CSHS Program and Abstracts
Halifax 2006 Organizing Committees
Agriculture and Agri-Food Canada's Greencover Program
Canadian Society of Horticultural Science
Wednesday, August 2, 2006
13:30 Environmental losses of soil applied nitrogen in wild
blueberry production. Gloria Thyssen*, Dr. David Percival and Dr. D.
Burton, Nova Scotia Agricultural College, Truro, NS, Kevin Sanderson,
Agriculture and AgriFood Canada, 440 University Avenue, Charlottetown, PE.
Environmental losses of soil applied N-fertilizers through ammonia volatilization, ammonium and nitrate leaching, and greenhouse gas emissions (GHG) were examined in a wild blueberry production system. Volatilization trials were established in the vegetative phase of production in Nova Scotia (NS) and Prince Edward Island (PE) in 2004 and 2005. A controlled environment, leaching experiment was conducted in 2005 using intact soil cores collected from Debert, NS. The GHG experiment examined the loss of soil applied N through nitrous oxide (N2O), carbon dioxide and methane emissions, using a static non-steady state chamber. Treatments used in the volatilization trial consisted of no fertilizer (control) and N applications (35 kg Noha-1) of ammonium sulphate (AS), urea (U), diammonium phosphate (DAP) and sulfur coated urea (SCU). The leaching trial consisted of the aforementioned treatments, and the addition of isobutylidene diurea (IBDU) and Nitroform (NF). The GHG trial consisted of a control and AS. Results from the volatilization trials indicated significant treatment effects with U (NS in 2004, PEI in 2005) and DAP (NS in 2005) being significantly greater than the control. Significant results from the leaching trial were present, with IBDU having the highest nitrate leaching rate, and AS having the highest rate of ammonium leaching. N2O emissions were found to be minimal, with no significant treatment effects. Therefore, these results indicate that volatilization and leaching losses are significant and site specific and can provide the basis of inadequate growth.
Key words: nitrogen, wild blueberry, environmental losses, ammonium, nitrate
13:45 Compost teas and their effects on raspberry and strawberry
fruit quality. Jennifer Hargreaves1*, Phil R. Warman2, Sina
Adl3, 1Dalhousie University/Soil Ecol, LSC 5130, Dept of Bio. Life Sciences,
1355 Oxford Street, Halifax, NS, B3H 4J1, 2Dalhousie University/NSAC,
Compost teas are new products in the organic agriculture industry typically being used to control plant disease. However, organic farmers are also experimenting with this product as a "stand alone" product, one that may be beneficial because it impacts a plant more quickly than nutrients applied to the root zone. This research will investigate these claims by directly comparing the effects of non-aerated compost teas from different compost sources, composts, and fertilizer on the nutrient content and fruit quality of strawberries and raspberries grown in the field. Furthermore, recommendations on compost tea production methods have been debated for some time and so other experiments will focus on comparing compost tea nutrient content of aerated and non-aerated compost teas made from difference compost sources and their ability to provide nutrients to plants. Finally, it is claimed that compost tea properties begin to shift within 24 hours after production, so compost tea properties, including nutrient content and microbial community structure, will be monitored in aerated and non-aerated compost teas made from different sources for 6 weeks after production. The findings of this project will greatly aid in filling data gaps in compost tea research and help determine the suitability of these amendments for practical farming purposes. Preliminary results will be presented, specifically, the effects of storage on compost tea properties and results from the first harvest.
Key words: compost tea, raspberries, strawberries, antioxidants, MSW compost, Ruminant compost
14:00 Effect of mulch applications on nitrogen fertility and the growth and productivity of organically managed highbush blueberry plants. N.E. Burkhard1*, D.H. Lynch1, D.C. Percival2 , 1Nova Scotia Agricultural College, Department of Plant & Animal Sciences, P.O. Box 550, Truro, NS, B2N 5E3, Canada; 2Nova Scotia Agricultural College, Department of Environmental Sciences, Truro, P.O. Box 550, NS, B2N 5E3 Canada.
Weed management is a significant challenge in organic highbush blueberry (Vaccinium corymbosum L.) production due to an inability of existing registered herbicides to control within-row weeds. Mulch application may be a promising alternative; however, it can greatly influence soil nitrogen (N) dynamics. In 2005, a study was initiated at a commercial highbush blueberry operation in Nova Scotia to: 1) test the ability of 20 cm-thick mulches to suppress weeds and 2) asses their influence on N fertility, plant growth and crop yield. A split-plot experimental design was used with five blocks, six treatments and five plants (cv. Duke) per split plot. The whole plot factor consisted of mulch/fertility treatments and included: (i) control (no amendment), (ii) ammonium sulphate fertilizer (30 kg N ha-1), (iii) pelletized poultry manure (60 kg N ha-1), (iv) pine needles (80 t ha-1), (v) horse manure and sawdust compost (550 t ha-1), and (vi) seafood waste compost (360 t ha-1). The split plot factor consisted of level of hand weeding (- /+). Preliminary results of mineralizable soil N (monitored in situ using PRSTM anion/cation exchange membranes), seasonal changes in soil mineral N (NO3--N and NH4+-N), and plant response (leaf N, crop yield, plant canopy index) will be presented.
Key words: highbush blueberry; organic production; weed control;
14:15 Associations of citrus tree
decline, soil variability and
Diaprepes abbreviatus (L.) root weevil: two-case study in Florida. Hong
Li1*, Stephen H. Futch2, Robin J. Stuart2, James P.
Syvertsen2, and Clay
W. McCoy2, 1Nova Scotia Agricultural College, Department of Plant and
Animal Sciences, Truro, Nova Scotia, B2N 5E3, Canada. 2University of
Florida, IFAS, Citrus Research and Education Center, Lake Alfred, Florida
The hypothesis of associations of environmental soil heterogeneity with citrus tree decline and Diaprepes abbreviatus (L.) root weevil variability was tested in two flatwoods citrus groves in Florida. Studies were conducted on a loamy, poorly drained Mollisol in Osceola County, central Florida in 2002, and on a sandy, poorly drained Spodosol in DeSoto County, south-west Florida during 2001-2003. Adult weevils were monitored using 50 Tedders traps arranged in a 34 x 25 m grid at the Osceola site, and using 100 identical traps in a 30 x 15 m grid at the DeSoto site. Soil water content (SWC), texture, pH, Ca, Mg, Fe, Cu and other nutrients were measured at each trap. Soil was strongly acidic (pH 4.9±0.4) at the Osceola site but near neutral (pH 6.6±0.4) at the DeSoto site. The Mehlich-I extractable soil Mg and Ca were correlated to soil pH and SWC in both soils, and extractable Fe was related to pH, SWC and Mg in the Spodosol (0.30 < R2 < 0.65, P < 0.01). The weevil density was high in areas low in soil Mg and Ca in the acidic Mollisol, but high in areas with high soil pH, and Mg and low sand content in the near neutral Spodosol (P < 0.05). Tree decline was associated with soil Fe concentrations > 40 mg kg-1 in the Mollisol (P < 0.01), and weevil density was low at soil pH between 5.7 and 6.2. The range of spatial dependence of weevil population, soil pH, SWC, Fe, Mg and sand varied between 60-100 m in the Mollisol and the Spodosol. Soil-weevil-tree simple and multivariate linear models were established to put into practices for predicting and controlling the weevil population and tree decline in the future. Differences in site characteristics suggested the need for site-specific weevil and citrus tree management.
Key words: Citrus tree management, linear regression model, root weevil
control, soil pH, soil-weevil overlay patterns.
14:30 Use of plant growth regulators to increase bioactive compounds
in the wild blueberry. Joanna MacKenzie* and David Percival, Nova
Scotia Agricultural College, Truro, Nova Scotia Canada.
Key words: wild blueberry, plant growth
14:45 The impact of 'surround' on leaf gas exchange of
apple trees in New Brunswick. J.P. Privé*, L. Russell, and A.
LeBlanc, Agriculture and Agri-Food Canada; Atlantic Food and Horticulture
Research Centre, Bouctouche, New Brunswick, Canada.
Key words: kaolin, leaf physiology, photosynthesis, stomatal conductance, intercellular CO2, transpiration.
15:00 Root Weevils and Strawberry - Just how many are too many? Kenna MacKenzie*, Julia Reekie, Micheal Binns and Beata Lees, Agriculture and Agri-Food Canada, Kentville, NS B5N 1J5.
Root weevils are a concern for strawberry production across the world. Yet, no damage threshold has been determined for root weevils in commercial strawberry production. Two experiments were run where individual six week old strawberry plants were innoculated with known numbers of black vine weevil eggs. Two cultivars, Kent and Annapolis (rated as susceptible and tolerant to root weevil feeding respectively), were used. In the first experiment treatments of 0, 6, 12, 24, 48, 96 and 192 eggs per plant were used, while 0, 3, 6, 12, 24 and 48 were used in the second experiment. Live and dead leaves, crown and roots were weighed and the number of larvae per pot were counted. Plants at the higher doses (48 and up) in experiment one showed high mortality and poor growth. In the second experiment, there was no effect of root weevil feeding seen with Annapolis while Kent plants at 48 eggs per plant treatment had smaller root systems. These results demonstrate that root weevil feeding has little, if any, effect on strawberry growth at least under ideal conditions. Interactions between root weevils and other stresses such as root diseases may be responsible for major losses seen in field situations.
Key words: Otiorhychus sulcatus, economic threshold, root weevils, strawberry
Wednesday, August 2, 2006
Oral Presentations Abstracts
16:00 Chlorophyll Fluorescence as an indicator of physiological change in plants. John M. DeLong*, Robert K. Prange, Atlantic Food and Horticulture Research Centre, Agriculture and Agri-Food Canada, 32 Main St., Kentville, Nova Scotia, B4N 1J5.
Chlorophyll fluorescence (CF) has been termed a rich, but ambiguous signal. Since Kautsky's observations of leaf fluorescence in the 1930s, the development of theoretical aspects of fluorescence have paralleled advances in understanding the mechanisms involved in the light reactions of photosynthesis. The development of pulse amplitude modulated (PAM) fluorometry in the 1980s facilitated a boom in the use of CF as standard methodology for detecting plant stresses in their myriad forms. CF is popular because it is rapid and non-destructive, facilitates repeated observations on the same experimental unit and provides direct measurements of fundamental photosynthetic reactions. CF techniques have been used for measuring plant responses to: excess and UV light, herbicides, water stresses, low oxygen environments and high and chilling temperatures, to name a few. CF methods have been developed to monitor in vivo excitation energy distribution, oceanic photosynthesis, adaptation of plants to changing light regimes, senescence, insect damage and even fruit ripening and quality! This presentation will highlight application of CF as an indicator of physiological change in plants due to alterations in growth or storage environments (stress responses) and normal senescence metabolism (non-stress responses).
Key words: photosynthesis, fluorescence, PAM, HarvestWatch
16:15 The effects of handling and postharvest dehydration on grape
berry chlorophyll fluorescence, mass loss and visual colour. Harrison
Wright1,2*, John Delong1, Robert Prange1 and Rajasekaran
Food and Horticulture Research Centre, Agriculture and Agri-Food Canada,
Kentville, NS, B4N 1J5, Canada; 2Department of Plant and Animal Sciences,
Nova Scotia Agricultural College, PO Box 550, Truro, NS, B2N 5E3.
Two experiments were designed to test the effects of handling on primary chlorophyll fluorescence parameters (Fo, Fm, Fv/Fm), colour change and dehydration dynamics in a green seedless table grape cultivar. In experiment 1, the effect of barehanded, gloved and pedicel-handled grapes and a high intensity light saturation pulse was compared to an untouched control. Experiment 2 investigated the effects of handling grapes at different stages in dehydration. Non-significant differences in '% mass loss' were observed among the different handling protocols. Handling grapes increased senescent-like browning of the berries when touched with bare or gloved hands compared with pedicel-handling. Exposing grapes to the saturation pulse of the fluorometer did not change berry colour or any fluorescence parameters. Fluorescence measurements indicated that the control grapes (no handling) senesced less than the three handled treatments and that the pedicel-handled grapes senesced less than the glove and bare-hand treatments. The senescence-promoting effect of handling on the fluorescence measurements and berry colour was significantly less on grapes treated immediately after they were brought into the lab compared with those that sat out (7 days +) before they were handled. This study shows that postharvest handling influences grape berry chlorophyll fluorescence, mass loss and visual colour.
Key words: barehanded, gloved hand, pedicel
handled, saturation pulse,
16:30 Biochemical characteristics of selected advanced lines and
commercially grown raspberry cultivars. Shahrokh Khanizadeh1, Behrouz
Ehsani-Moghaddam1, and J. Alan Sullivan2*, 1Agriculture and Agri-Food
Canada, Horticultural Research and Development Centre, 430 Gouin Blvd.,
St-Jean-sur-Richelieu, QC, Canada, J3B 3E6; 2Department of Plant
Agriculture, University of Guelph, Guelph, ON, Canada, N1G 2W1.
Three advanced raspberry lines from University of Guelph (88-18, 88-117, 88-134) and one from Quebec fruit breeding programs (SJR942-7) were tested in Quebec for their winter hardiness, fruit quality and performance, and compared to four commercially grown cultivars ('Festival', 'Boyne', 'Nova' and 'Killarney'). The selected lines were evaluated for their total antioxidant capacity, soluble solid contents, and acidity. The crude, hydrophilic and lipophilic antioxidant content of fruit were measured using the Trolox Equivalent Antioxidant Capacity (TEAC) method. Significant variation was observed for crude, hydrophilic and lipophilic antioxidant values among the advanced raspberry selections. The highest crude, hydrophilic and lipophilic activities were found in 88-18 with 24.06 ± 0.87, SJR942-7 with 16.80 ± 0.13, and Boyne with 0.53 ± 0.06 µmol TE/g FW, respectively.
Key words: antioxidant, Phenolics, shelf life
16:45 Apple peels as a value-added food ingredient in a model muffin system. H.P.V. Rupasinghe*, L. Wang, G. Huber, and N.L. Pitts, Department of Environmental Sciences, Nova Scotia Agricultural College, Truro, Nova Scotia B2N 5E3, Canada.
Apple fruit skin, a rich source of dietary fiber and many health-enhancing phenolics, is a by-product of apple processing. The aim of this study was to investigate the feasibility of incorporating dried apple skin powder (ASP) as a value-added ingredient in bakery food products using a food model system of muffins. The blanched, dehydrated and ground ASP (2 mm particle size) was incorporated into muffins at 0, 4, 8, 16, 24, or 32% (w/w) levels by replacing an equivalent amount of wheat flour in a standard muffin mixture. The effect of ASP substitution on texture, color, volume, proximate composition, total phenolic content and antioxidant capacity of muffins was determined. The level of total phenolics and antioxidant capacity of muffins was directly correlated to the amount of ASP incorporated. A taste panel of 65 untrained panellists showed that the 16% replacement level of ASP produced the bakery product most acceptable for organoleptic attributes. The effect of baking on individual phenolic constituents was determined by liquid chromatography mass spectrometry. The present study has demonstrated the potential for the industrial exploitation of ASP as a health food ingredient for bakery industry.
Key words: Malus edomestica, phenolics, antioxidants, food ingredient, baking
Vegetable growers in Atlantic Canada are at the mercy of long, harsh winters as they seek ways to diversify crops, gain access to early spring markets and capture price premiums. Over-wintering leeks is an opportunity to produce a high quality early vegetable. This study examined cropping system factors in over-wintering leeks in Southeastern New Brunswick and Nova Scotia's Annapolis Valley over three years. Experimental layout was a three by three cross design at each site, with each replicate containing all treatments. Treatments were combinations of eight cultivars and three row covers (bare soil, straw, non-woven polypropylene fleece). Data collected included winter and spring soil and air temperatures, yield of trimmed leeks and leek diameter. Results showed that over-wintering leeks is viable in both New Brunswick and Nova Scotia. Yields varied from less than 1.0 to 9.8 t ha-1 in New Brunswick, whereas yields in Nova Scotia varied from 4.2 to 15.3 t ha-1. Row covers improved yields compared with bare soil, although two cultivars yielded just as well on bare soil as under row covers. The high quality and small diameter of over-wintered leeks at the New Brunswick site suggests an opportunity for a niche market "New Brunswick Baby Spring Leek."
Key words: Leeks, winter, row cover
08:45 Potassium management for carrots in Prince Edward Island. K.R. Sanderson* and J.B. Sanderson, Agriculture and Agri-Food Canada, Crops and Livestock Research Centre, Charlottetown, PE Canada C1A 4N6.
Nine field studies were conducted over a three-year period to determine the response of carrot (Daucus carota L.) to soil-applied K on sandy to loamy sand Orthic Podzol soils in Prince Edward Island. Sites were classified based on K rating as L-, L, and M (Mehlich-III extractant) according to the PEI Soil and Feed Testing Laboratory. Treatments consisted of broadcast applied muriate of potash at 0, 75, 150, 225 and 300 kg K ha-1. Total carrot yields were 70, 90 and 98% of maximum yield when no K was applied, while 150, 75 and 0 kg K ha-1 were required to achieve 95% maximum yield for the L-, L and M soil K ratings, respectively. Increasing rates of applied K linearly increased the K content of tissue and soil taken at harvest. Root K content increased linearly with rate of applied K and parallel line analysis indicated separate lines were required for each K soil test rating.
Key words: Carrots, potassium, yield, root content
09:00 Assessing different nitrogen use efficiency indices using field-grown green bell peppers. Laura L. Van Eerd*, University of Guelph Ridgetown Campus120 Main St. E.,Ridgetown, Ontario N0P 2C0 Canada.
Rising crop input costs and pressure to protect the environment has increased interest in improving nitrogen use efficiency (NUE), while maintaining crop yields and minimizing N losses. The aforementioned parameters were assessed in two green bell pepper field experiments per year. In two contrasting years (i.e. cool/wet vs. warm/dry), marketable yield response to N application was either positive or no response was observed. In most experiments, the quantity of N (0-210 kg N/ha), application timing (preplant vs. split) and N source (ammonium nitrate vs. urea with nitrification and urease inhibitor) did not influence total and marketable yield nor measured fruit quality parameters. Total percent N in the fruit and shoot was lower in non-fertilized plants compared to plants receiving 70 or 210 kg. N/ha. There were considerable differences between locations in soil mineral N, yield, NUE, and plant N uptake and removal. Moreover, NUE (i.e. apparent N recovery) and agronomic efficiency decreased as N application increased from 70 to 210 kg N/ha. However, this was not observed when physiological efficiency and N harvest index were quantified. Thus, the interpretation and applicability of NUE depends on the goals of the research and which index was used.
Key words: nutrient use efficiency, green bell peppers, harvest index, nitrogen, fertilizer
09:15 Potatoes transformed for enhanced tolerance of temperature stress. D.R. Waterer* and L.V. Gusta, Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8.
Potatoes (Solanum tuberosum) are sensitive to temperature stress both in the field and during storage. This project evaluated the yield, quality and stress tolerance of potato (cv. Desiree) transformed with a range of genes involved in adaptation or resistance to environmental stress. The genes introduced via Agrobacterium-mediated transformation were; dehydrin 4 (Dhn4) isolated from barley, mitochondrial Mn superoxide dismutase (SOD) from wheat, CBF1 from canola and ROB5 from bromegrass cell culture. The genes were linked to either the constitutive 35S promoter or a stress-induced Arabidopsis COR78 promoter. In a series of controlled environment trials, the transformed lines were exposed to low or high temperature stress as developing plants or as harvested tubers. Transformation with SOD or ROB5 appeared to improve tolerance to low and high temperature stress both during development and in storage. Similar results were obtained in field trials if the crop was exposed to significant heat or drought stress. When the field trials were managed to minimize stress, none of the transformed lines produced higher yields or had any obvious quality advantage relative to the parental material. The COR78 promoter appeared to be as effective as the 35S promoter but without the metabolic cost of constitutive expression.
Key words: dehydrin, superoxide dismutase, ROB5, CBF1
09:30 Effect of sowing depth on emergence, growth and yield of Okra (Abelmoschus esculentus L.) Moench in South West Nigeria. F.O. Odeleye1*, O.M.O.Odeleye2, J.K.Vessey3, Z.Dong3, F.B.Yakubu4, and A.O.Olaleye5, 1Dept. of Crop Protection and Environmental Biology, University of Ibadan, Nigeria, 2National Horticultural Research Institute, Jericho, Ibadan, Nigeria, 3Dept. of Biology, St. Mary's University, Halifax, N.S., Canada. 4Federal School of Forestry, Jericho, Ibadan, Nigeria, 5Dept. of Soil Science and Farm Mechanization, Olabisi Onabanjo University, Ago-Iwoye, Nigeria.
Pot and field trials were conducted to evaluate the effects of sowing depth on the performance of two varieties of Okra grown as sole crop. The trials involved factorial combination of 5 sowing depths (1,2,3,4,and 5cm) with 2 varieties of okra in randomized complete block with 4 replicates. The experiments were carried out in pots and the experimental plot of the Dept. of Crop Protection and Environmental Biology, University of Ibadan, Nigeria. The data taken on days to emergence, growth and yield parameters were subjected to ANOVA using SAS and means were separated using LSD and SE. Results showed that sowing okra 4cm and 5cm deep significantly reduced % seedling emergence and caused a significant decrease in the vegetative growth, dry matter accumulation and yield of okra in pots and on the field. The 5cm depth is the most damaging in this regard. Good seedling emergence were obtained at I, 2 and 3 cm sowing depths but the 3 cm depth appears to be the optimum sowing depth as highest yield and overall best performance of okra were attained at this depth. The two varieties of okra used in this study responded similarly to depths of sowing but NHAe 37-4(medium maturing) out yielded LD88( early maturing) apparently because of its longer life cycle and its larger leaf area which enabled it produced more fruits over time during its life cycle.
Key words: sowing depth, Okra, emergence, growth, yield
09:45 Response of Cucumber to time of fertilizer application in South West Nigeria. F.O. Odeleye1*, O.M.O Odeleye2, J.K.Vessey3, Z. Dong3and H.N. Ebuzome1, 1 Dept. of Crop Protection and Environmental Biology, University of Ibadan, Ibadan, Nigeria, 2National Horticultural Research Institute, Jericho, Ibadan, Nigeria, 3Dept. of Biology, St. Mary's University, Halifax, N.S. B3H 3C3, Canada.
A field trial was conducted on the experimental farm of the Department of Crop Protection and Environmental Biology, University of Ibadan, Nigeria, to determine the growth and yield response of cucumber to time of fertilizer application. The cucumber variety used was Poinsett. Applying N.P.K( 20:10:10) fertilizer at the rate of 150 kgNha-1, the treatments comprised applications at: planting, 3 weeks after planting (WAP), 6 WAP; split applications at planting + 3 WAP, at planting + 6 WAP, at 3 WAP + 6 WAP and control to which no fertilizer was applied. The experimental design was randomized complete block with 4 replications. Means were separated using Duncan's Multiple Range Test at the 5% probability level. Results from the experiment showed that cucumber plants that were fertilized at one time or the other generally performed better than control plants in terms of vegetative growth and yield. However, comparing the times of fertilizer application treatments, fertilizer applied entirely at 6 WAP was the least beneficial to cucumber plants , application of the entire fertilizer at planting or the split application of fertilizer at planting + 3 WAP engendered a high level of vegetative growth but lower fruit yield compared with split application at 3WAP+6WAP. The split application of fertilizer at 3 WAP+ 6 WAP was optimal for the performance of the crop in terms of vegetative growth and fruit yield in South West Nigeria.
Key words: Cucumber, N.P.K., time of application, vegetative growth, fruit yield.
Oral Presentations Abstracts
10:30 Taming the Wild Rose. R. Barry1*, K. Sanderson2 and J. Kemp1, 1Department of Biology, University of Prince Edward Island, 550 University Ave., Charlottetown, PE C1A 4P3 and 2Agriculture and Agri-Food Canada, 440 University Ave., Charlottetown, PE C1A 4N6.
Roses of the genus Rosa are found growing wild throughout the Atlantic Provinces in a multitude of different habitats. Rose hips, the marketable product from these roses, are a rich natural source of bioactive compounds useful in the pharmaceutical industry. In 2004 a wild rose field trial was established at the Agriculture and Agri-Food Canada Harrington Research Farm on Prince Edward Island. Planting stock for this trial was propagated from wild rose populations throughout PEI. Treatments were applied at planting and included: in-row mulch (none, bark and straw), between-row (tilled and sod) and in-row fertility (none, compost and chemical fertilizer). In-row mulch and fertility treatments were reapplied in 2005. Straw mulch proved to be the most effective in-row mulch for promoting new shoots, increasing plant spread and shoot length. Between-row tilled treatment proved better than between-row sod for promoting plant spread, shoot length, shoot diameter, and rose hip yield. The most effective in-row fertility treatment was the chemical fertilizer which resulted in a greater plant spread, shoot length, and rose hip yield than the other two treatments. Outcomes from this experiment will be used to establish protocols for commercially growing wild roses as an agricultural crop for the Atlantic Provinces.
Key words: wild rose, rose hip, Rosa sp., alternative crop, field production
10:45 Predicting Weekly Yields of Greenhouse-Grown Sweet Peppers. W. C. Lin1* and B. D. Hill2, 1Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, P.O. Box 1000, Agassiz, British Columbia, Canada V0M 1A0, 2Research Centre, Agriculture and Agri-Food Canada, P.O. Box 3000, Lethbridge, Alberta, Canada T1J 4B1.
Sweet peppers (Capsicum annuum L.) grown in commercial greenhouses are harvested when they are fully coloured. The production season of greenhouse peppers is about 10 months each year. In this study, sweet peppers were grown in an experimental greenhouse to examine the irregular patterns of weekly yields. Peaks-and-valleys in weekly yield occurred in each of five years with both red and yellow sweet peppers. Records of weekly yields and associated environmental data were used in formulating models with artificial neural networks (ANN). ANN models accommodated two different cultural practices: conventional one fruit per node and fruit-pruned to one fruit for every other node. It appears that red peppers yields can be predicted four weeks ahead, but yellow peppers only one week in advance. ANN models may require validation with prevailing cultivars and cultural practices, when they are markedly different from the original data used in formulating the ANN models. Our results indicate that ANN models can be improved by continuously updating with data consisted of different cultural practices and cultivars. ANN models are superior or equivalent to regression models. The relationship between peak production week and environmental factors of greenhouse-grown sweet peppers will be discussed.
Key words: greenhouse, production, sweet peppers, predictive models,
Greenhouse-grown sweet peppers (Capsicum annuum L.) are commercially harvested when fully colored. This study examined whether storage at temperatures lower than recommended 7.5oC for four weeks would be possible. Red and yellow peppers were stored for four weeks at 1oC, 2.5oC, 5oC, 7.5oC, 10oC, and 12.5oC, followed by a 3-day shelf life evaluation at 20oC. Each fruit was visually rated for decay from none (0) to severe (5). Fruit from commercial and experimental harvests were compared. With commercial harvests, red peppers had low decay at 5oC, 7.5oC, and 10oC, while yellow peppers had low decay at 10oC or 12.5oC. A rapid increase in decay index (more than 2.5) upon return to room temperature after four-week storage at 1oC and 2.5oC indicated possible chilling injury. Storage at 5oC or higher did not result in a rapid increase in decay index (less than 1.0). With experimental harvests, red peppers were more tolerant to 5oC or 7.5oC than yellow. In general, sweet peppers harvested from the experimental greenhouse had less decay than those from a commercial source. This study indicated that fully colored sweet peppers could be stored at 5oC for four weeks without indication of chilling injury.
Key words: post-harvest, quality, shelf life, sweet pepper, storage temperature
11:15 Responses of a Long Greenhouse Tomato Crop to Summer CO2 Enrichment. Xiuming Hao, Qingguo Wang* and Shalin Khosla, Greenhouse and Processing Crops Research Centre, Agriculture and Agri-Food Canada, 2585 County Rd. 20, Harrow, Ontario, Canada N0R 1G0.
Responses of greenhouse tomatoes to CO2 enrichment are strongly influenced by duration of the CO2 enrichment and greenhouse climate. While CO2 enrichment generally benefits tomato fruit production in winter its effects on summer tomato production (under high air temperature and strong ventilation) are still not clear, especially when the crop has been subjected to long term of CO2 enrichment in winter. Therefore, a study was initiated in 2005 to determine the feasibility of summer CO2 enrichment in southwestern Ontario, a major greenhouse vegetable production area in North America with very hot summer. The long tomato crop (cv. Rapsodie) was planted into rockwool slabs in six greenhouse compartments in January. From January to the middle of June, the tomato plants in all six greenhouse compartments were subjected to the same standard CO2 enriching practice. From the end of June to August, three CO2 treatments (two compartments for each treatment) were applied: Control (ambient), Enrich1 (800 ppm when ventilation was less than 10% and 400 ppm when less than 50%) and Enrich2 (1200 ppm when ventilation was less than 10% and 500 ppm when less than 50%). The CO2 enrichment was stopped when ventilation requirement was more than 50%. Leaf photosynthesis, as indicated by the CO2 response curve, partially acclimated to the CO2 enrichment. Stem dry weight was increased while fruit dry weight was reduced by the summer CO2 enrichment. Marketable fruit yield was also reduced by the summer CO2 enrichment. High air temperature might have affected fruit setting and thus limited the response to CO2 enrichment. Further investigation on carbohydrate translocation is needed to clarify the mechanism limiting the response of greenhouse tomatoes to summer CO2 enrichment.
Key words: Photosynthesis, Lycopersicon esculentum, high temperature stress, acclimation
11:30 Neural networks to predict harvest dates of greenhouse-grown sweet peppers. B. D. Hill1*, W. C. Lin2, 1Lethbridge Research Centre, Agriculture and Agri-Food Canada, P.O. Box 3000, Lethbridge, Alberta, Canada T1J 4B1, 2Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Box 1000, Agassiz, British Columbia, Canada V0M 1A0.
Sweet peppers (Capsicum annuum L.) grown in the greenhouse display a pattern of irregular weekly yields. Modelling the colouration of individual fruit may help growers predict the number of harvestable (fully coloured) peppers in advance. We monitored the red, green and blue colour intensities of developing fruit via digital image processing. These colour measurements together with crop and environmental variables were used as inputs into neural network (NN) models to predict days-to-harvest (D-to-H) for individual fruit. When 18 inputs were evaluated, the 'best' model used only five of the inputs to predict D-to-H for red peppers with a R2 of 0.79 and root mean square error (RMSE) of 3.4 d. Predictions were more difficult for yellow peppers. The 'best' model used eight inputs and achieved a R2 of 0.69 and RMSE of 4.4 d. Light and temperature had only minor effects on predictability. Further testing indicated that equivalent NN predictions could be obtained using only three inputs (Julian day, nodal position of the target fruit, ratio of red:green intensities). The R2 of NN models were higher than those of corresponding regression models. We concluded that NN have considerable potential to assist greenhouse operators predict the D-to-H of sweet peppers.
Key words: greenhouse, fruit, colouration, digital imaging, neural networks
Friday, August 4, 2006
Small fruits are genetically heterozygous and characterized as "not coming true from seeds". The conventional methods, although successful for vegetative propagation of these fruits, are slow and labour-intensive and few propagules are produced from a selected clone or hybrid. Micropropagation techniques are important for clonal multiplication, germplasm improvement and gene conservation of Canadian small fruits: Fragaria (strawberries), Rubus (raspberries, cloudberries) and Vaccinium (blueberries, cranberries, lingonberries, etc.) species. The in vitro propagation of these species using axillary bud proliferation and adventitious shoot regeneration has been investigated in a number of studies. The morphogenesis seems to be highly dependent on plant growth regulators and media used for culture, which is again genotype specific. The paper presents the progress in-depth of various aspects of Canadian small fruits species in vitro, on gelled and in liquid media using bioreactors, for their commercial production. It also discusses the relationship between molecular diversity and in vitro propagation, the production of apparently rejuvenated clones and the issues that still need to be addressed to utilize the full potential of plant tissue culture techniques in mass propagation of Canadian small fruit nuclear stocks.
Key words: Fragaria, Rubus, Vaccinium, micropropagation, bioreactor
14:10 Horticultural plant conservation: management and commercialization. John T. A. Proctor*, Dept. of Plant Agriculture, Bovey Bldg., University of Guelph, Guelph, Ontario, N1G 2W1.
Most Canadian crop plants originated outside Canada, e.g. corn from Mexico, soybeans from China. Germplasm for these crops is retained in the Canadian Plant Germplasm System (CPGS) so that their genetic diversity, and that of their wild relatives, is preserved. A small number of Canadian crop plants are native to Canada, e.g. strawberry, raspberry and ginseng. Ginseng is one of Canada's oldest crop plants and featured in the early fur trade. It is Canada's most important pharmacological crop.The CPGS preserves some native crops, but not ginseng. In this review the history, genetic diversity, crop management and commercialization of ginseng will be described. Worldwide the ginseng genus (Panax L.) has 11 species, 9 from Asia and 2 from North America, P. quinquefolius and P. trifolius. The genus is genetically diverse and the crop plant basically undomesticated. Wild ginseng is listed as endangered in the 1999 list of Canadian species at risk.
Key words: genetic resources, ginseng, medicinal herb
14:50 Fresh-cut apples: Challenges and opportunities for multi-disciplinary research. Peter M.A. Toivonen*, Agriculture and Agri-Food Canada, Summerland, B.C. Canada V0H 1Z0.
The fresh-cut apple industry has just become established in North America. Much of this development has been a result of multi-disciplinary work to find integrated and reliable solutions to problems. The future looks very bright for this fruit product, however growth and improvement in the quality and relative production costs will require further work. The existing industry has grown from concept to reality in response to research activities in package technology, sensory analysis, postharvest physiology, postharvest pathology and food microbiology. Several examples of how these critical research inputs impacted and continue to impact on the industry practice. The next generation of questions and challenges posed by the industry will require some new inputs. One example is that the dip used to control cut-edge browning in fresh slices is reported to be the most expensive component. New cultivars of apples which do not brown can potentially remove this cost of production. However, these new cultivars will also create challenges in regards to postharvest storage research to optimize their condition and availability to the fresh-cut processor over a storage season. Another issue which continues to plague the industry is secondary browning, a problem caused by fungi. Sporadic occurrence during the storage season and between lots in a storage has required research to develop predictors of lot to lot variation in susceptibility. More recently, a new technology involving 1-MCP may hold promise as a final solution to this insidious and unpredictable problem. The very nature of fresh-cut fruit has and continues to require a coordinated multi-disciplinary research strategy.
Key words: Value-chain, value-added, apples, fresh-cut, integrated research
Friday, August 4, 2006
The amount of fruit and vegetables produced under organic production systems, irrespective of how "organic" is delimited, has been steadily increasing. Organic production is largely based on cultivars that were originally developed for conventional production systems. The prospects of breeding specifically for organic systems are intriguing. One approach is identifying the major constraints with which organic growers must contend (often diseases or insect pests) and then incorporating stable genetic resistance. A more complex approach is to define an organic crop ideotype and derive an index of traits as a selection criterion. How effective are these methods expected to be in improving clonally propagated fruit crops? In addition to the importance of the breeding goals, the technologies employed are also of concern. The topic will be examined with special reference to breeding strawberries and apples.
Key words: Fruit breeding, strawberries, apples, disease resistance, selection environment
17:00 The Current Status of Organic Horticulture Research in Canada and Recent Linkages with International Scientists in Organic Apple and Pear Production Research. Charlee G. Embree, Research Scientist, Study leader for Organic Horticulture, Agriculture and Agri-Food Canada, Kentville, Nova Scotia, Canada B4N 1J5.
Organic horticulture research has been conducted by Agriculture and Agri-Food Canada (AAFC) Scientists throughout the Nation for a number of years. The research projects have in all cases been conducted in conjunction with or complimentary to the scientists primary focus. Extensive research reports have therefore been few. Often results are made available directly to the industry producers, through the popular press or in technical publications. There is evidence that this is changing as horticultural research scientists learn of the industry's need to produce more certified organic produce to meet expanding market opportunities. The greenhouse vegetable industry is a good example. Research in organic tree fruit production in Canada is also in its early stages of development. In Feb 2006 it received a strong stimulus however, when a group of AAFC, ISHS and the Organic Agriculture Center for Canada scientists joined with the regional organic network (ACORN) to host the First International Apple and Pear Symposium in Nova Scotia. This paper will attempt to document the current status of organic research in Canadian Horticulture and to report the highlights of the International Apple and Pear Symposium.
Wednesday, August 2, 2006
P107 The Halifax experimental pollen and spore monitoring and forecast program: 5-year results and trends. Benjamin J.A. Moulton1, David H.S. Richardson1, David L.Waugh2, and Ann A.L. Miller1,3*, 1Department of Biology, Saint Mary's University, 923 Robie St, Halifax, NS, B3H 3C3, 2Atmospheric Science Division, Meteorological Service of Canada - Atlantic Region, Environment Canada, 45 Alderney Drive, Dartmouth, NS, B2Y 2N6; 3marine g.e.o.s., 1003 Peter St., Apt. 1, New Minas, NS, B4N 3L7.
This pollen and spore monitoring programme has been in operation since 2000. Pollen levels are monitored in Halifax, Beaverbank, and Noel, urban, suburban and rural sites, respectively. Pollen forecasts are made based on the pollen found and the expected weather. Here trends in the 5-year pollen records are reported. Pollen and spores are allergenic to sensitive individuals, causing hay fever symptoms to chronic asthma. The forecasts can help predict high-risk periods of allergic reactivity, allowing individuals to modify their daily activities, minimizing the need for medical treatment, reducing the risk of developing serious or chronic respiratory illness, and decreasing the demands on the health care system. Plant reproductive behaviour, weather, and climate are complexly inter-related with the incidence of hay fever / asthma. Vegetation patterns (composition, seasonality, ranges) are changing, as temperatures increase, precipitation becomes more variable, and atmospheric carbon dioxide levels rise, all the result of global warming. Plants are flowering sooner, flowering seasons may be longer, and some produce more pollen. Plants at more inland sites in Nova Scotia tend to flower and release pollen earlier. Long-term monitoring may reveal early indications of vegetation responses to global warming.
Key words: Airborne pollen, pollen monitoring, Nova Scotia 5 year pollen calendars, pollen forecasts, pollen, weather and allergies.
P108 Temporal, compositional, and density characteristics and differences of airborne pollen and spore records from Halifax, Kentville and Sydney, NS. Erin Pitman1*, Ann A. L. Miller1,2, David H.S. Richardson1, and David L. Waugh3, 1Department of Biology, Saint Mary's University, 923 Robie St, Halifax, NS, B3H 3C3; 2marine g.e.o.s., 1003 Peter St., Apt. 1, New Minas, NS, B4N 3L7; 3Atmospheric Science Division, Meteorological Service of Canada - Atlantic Region, Environment Canada, 45 Alderney Drive, Dartmouth, NS, B2Y 2N6.
Since 2000, the Saint Mary's University-Environment Canada Experimental Pollen and Spore Monitoring Programme has been operating in Nova Scotia. Airborne pollen and spore levels have been recorded at three equi-latitudinal sites. This year one sampler remains situated in Halifax, and the others are located at Agriculture Canada's Kentville Research Station and Cape Breton University, allowing monitoring over greater geographical and climatic ranges. Halifax and Sydney are exposed to cool coastal elements, whereas Kentville is inland at the eastern end of the Annapolis Valley, in the lee of the North Mountain. The Kentvillle sampler is adjacent to Environment Canada's automatic weather station, allowing correlation of pollen species and densities with local weather conditions. The temporal differences in pollen release by natural vegetation, and the compositional differences and densities of the pollen assemblages have been measured. Some differences appear to be due to biannual reproductive behaviour and to local weather conditions, but others can be attributed to the latitudinal differences and prevailing climatic conditions. It has been possible to examine records of fruit tree and agricultural crop pollen release and correlate this with that from natural vegetation.
Key words: Pollen monitoring Nova Scotia, pollen and climate, pollen and vegetation, pollen calendars and climatic temporal shifts
P109 Wendy, a new early season strawberry. Andrew R. Jamieson*, Agriculture and Agri-Food Canada, Atlantic Food and Horticulture Research Centre, 32 Main Street, Kentville, NS B4N 1J5.
Wendy is a productive, short-day cultivar adapted to matted-row culture in eastern Canada. Harvest of Wendy is in early season, concurrent with Evangeline. Primary fruit are wedge-shaped; subsequent fruit are conic. Fruit are larger than for Evangeline with similar color and firmness. Berries of Wendy have excellent fresh flavor. Plants are vigorous and productive in matted rows. Plants are moderately resistant to powdery mildew but susceptible to Verticillium wilt. The reaction to red stele root rot has not been defined. Wendy is introduced as an early season alternative to Evangeline and Veestar with improved fruit size and yield.
Key words: Fragaria xananassa Duch., cultivar description, fruit breeding
P110 Certain natural and synthetic compounds act as anti-transpirants. Rajasekaran Lada1, B. Theakston2, A. Adams1*, T.J. Blake2, 1Department of Plant and Animal Science, Nova Scotia Agricultural College, P.O Box 550 Truro, NS B2N 5E3 Canada, 2Earth Science Centre, Faculty of Forestry, University of Toronto, 33, Wilcocks Street, Toronto, M5S3B3, Canada.
Water is a scarce resource and nearly 75% of the underground water has already been depleted, mostly through agriculture. Controlling stomatal opening without any phytotoxic effects on plants is advantageous under water limiting conditions and to conserve soil moisture. A study was conducted to screen potential anti-transpirant compounds for their ability to reduce stomatal conductance and leaf transpiration in carrot seedlings. Carrot seeds var. Oranza were sown in 6" pots containing Promix™ and grown under greenhouse conditions (21ºC day, 14ºC night) for 3 weeks. Each pot received 250 ml of water per day. Twenty compounds were applied as a foliar spray. Each treatment was replicated 4 times with untreated and water treated controls for each. Sprays were applied at 10:00 am and allowed to dry on the leaves before measurements were taken between 10:45 and 11:45 am using a LI-1600 Steady State Porometer (LiCor, USA). Our previous studies revealed that stomata in carrot seedling are most active during that time. Of the twenty compounds screened, Wiltpruf™, Leafsheild™, N-Methyl-L-Proline, and BIOPROTECT™ were all effective at reducing stomatal conductance (Cs) and leaf transpiration (Tl). Compounds such as Potassium chloride, 1-2-4 Triazole, Trans-4-Hydroxy-L-Proline, Spermine and Spermidine all increased Cs and Tl.
Key words: anti-transpirant, stomatal conductance, leaf transpiration
P111 Regulation of superoxide dismutase isoforms in resistant strawberry cultivar subjected to leaf spot disease. Behrouz Ehsani Moghaddam* and Shahrokh Khanizadeh, Agriculture and Agri-Food Canada, Horticultural Research Development Centre, 430 Gouin Blvd., St-Jean-sur-Richelieu, Québec, Canada, J3B 3E6.
Two June bearing strawberry cultivars, Joliette (resistant) and Kent (susceptible) were inoculated with Mycosphaerella fragariae pathogen. Macroscopic symptoms characterized by red spots were observed on leaves thirty days after inoculation. Comparison of the Superoxide dismutase isoform profiles obtained by gel electrophoresis in all samples extracted from both resistant and susceptible cvs indicated one constant sharp band identified as Mn-SOD with 19 kD molecular mass. The intensity of this band in all samples derived from resistant cv was greater than that of susceptible. Another SOD isoform was also disclosed as a CuZn-SOD with 16 kD molecular mass, detected in all soluble proteins derived from resistant cv. This isoform was not observed in susceptible cv, however, with an increment of the amount of loaded protein, it was illuminated as a faint band in sample collected 3 d after inoculation, indicating insufficient production of CuZn-SOD isoform in susceptible cv during oxidative burst induced by the M. fragaria pathogen. Several bands were also characterized in both cv containing jointly Fe and Mn as their co-factors (Fe, Mn-SOD). In the resistant cv the activity of Fe, Mn-SOD isoforms gradually and regularly increased and reached to their highest level during the third day after inoculation. In comparison, the activity of the isoforms changed irregularly over the 20 days of the survey after inoculation.
Key words: Red spot, Disease resistance, SOD, Isoforms
P112 Spatial Variation of Wild Blueberry N, P and K Levels Using Hyperspectral Techniques. Camille Bourguignon1*, Dr. David Percival1, Dr. Jean-Pierre Privé2, Dr. Robin Robinson1 Nova Scotia Agricultural College, P.O. Box 550, Truro, Nova Scotia, Canada, B2N 5E3, 2AFHRC, Senator Hervé J. Michaud Research Farm, P.O. Box 2069, Bouctouche, New Brunswick, Canada, E4S 2J2.
Current wild blueberry leaf macronutrient assessment analyses are costly and time consuming and generally provide an overview for blanket fertilizer applications. Hyperspectral techniques using wavelengths in the visible and near-infrared spectra have been considered as an alternative for various crops. Nutrient assessment research at the site (CASI 550) and plot (FieldSpec Pro radiometer) levels were used to determine if spatial variations of wild blueberry leaf N, P and K contents could be determined in commercial fields. In May 2004, a multiple location N-P-K experiment (16 treatments, 4 replications) was established in Mount Thom, Nova Scotia. Nitrogen (0-80 kg Noha-1, as (NH4)2SO4), phosphorus (0-220 kg P2O5oha-1, as TSP) and potassium (0-80 kg K2Ooha-1, as MOP) were applied to induce variations in corresponding leaf nutrients contents. Leaves were sampled in August 2004 and 2005, as well as in June 2005. Foliar N (LECO auto-analyzer), as well as foliar P and K (ICAP), were determined. CASI 550 data was acquired at Mount Thom (833 m altitude) at dates similar to those of leaf sampling. Radiometer data was collected in 2005 (2 m above ground) at dates corresponding to CASI data collections. Stepwise regressions and NDVI comparisons on CASI reflectances were done to estimate leaf N content. Preliminary analyses were completed on radiometric raw DNs to observe possible trends of foliar N, P and K variations.
Key words: V. angustifolium, nutrient management, hyperspectral, CASI, NDVI
P113 Current status of elderberry research in eastern Canada. Denis Charlebois* and Claude Richer, Horticultural Research and Development Centre, Agriculture and Agri-food Canada, 430 Gouin Blvd., St-Jean-sur-Richelieu, Quebec J3B 3E6.
American elderberry (Sambucus nigra ssp. canadensis) is a perennial shrub native to Eastern North America. Aside from being used as wind break or ground stabilizer there has been an increasing demand for its fruits mainly from the food colorants industry. To satisfy the demand of this industry alone more than 100 hectares would have to be planted. However little is known about this plant's cultivation. We report preliminary results from a long term study evaluating field performance, yield, fruits characteristics of the wild species and 5 selected cultivars (Kent, Nova, Scotia, Victoria and York). Under proper care all cultivars showed excellent winter survival from zone 5a to zone 2b. Branches are only moderately resistant to snow and ice load and can easily break if left unattached. Rapid growth (up to 1,5 m a year) can compensate for losses following bad winter conditions. Fruit production starts the second year in the field and can vary between 2 and 3 kg per plant. It reaches between 5 and 8 kg per plant the second year of production. Pigment content differs between cultivars; those producing larger fruits containing less pigment. Results obtained so far can be used to assist potential producers selecting the appropriate cultivars to suit their need.
Key words: Sambucus, elderberry, new crop, crop management, anthocyanin
P114 Potential to double crop vegetables on plastic mulch. T. Simms, J. Bantle, W. Hrycan and D. Waterer*, Department Plant Sciences, University of Saskatchewan, Saskatoon, SK S7N 5A8.
Double-cropping plastic mulches may increase cost-effectiveness while reducing the environmental impact of this method for enhancing growth of vegetable crops. In regions with a short growing season, double-cropping of mulches involves leaving the plastic in the field over winter. This extended exposure to the elements may negatively effect the physical and optical characteristics of the mulch. In 2005, black, clear and IRT mulches were used to produce pepper (Capsicum annuum) or cucumber (Cucumis sativus). Clear mulch produced the highest yields of both crops, followed by the IRT and black mulch. Light transmission characteristics of the mulches were noticeably altered after the first growing season. Part of this change was due to soil and debris on the surface of the mulch: when the mulches were washed, their light transmission characteristics more closely resembled new mulch. The light transmission characteristics of the IRT mulch changed more than the clear or black mulches. All the mulches were physically sound at the beginning of the second growing season. The light transmission characteristics of the mulches and the performance of tomatoes cropped on the mulch in the second season will be reviewed.
Key words: light transmission, pepper, cucumber
P115 Determination of flavonols in apple genotypes by liquid chromatography mass spectrometry. G.M. Huber1*, C. Embree2, and H.P.V. Rupasinghe1, 1Department of Environmental Sciences, Nova Scotia Agricultural College, Truro, Nova Scotia B2N 5E3, Canada, 2Atlantic Food and Horticulture Research Center, Agriculture and Agri-Food Canada, Kentville, Nova Scotia B4N IJ5, Canada.
Growing evidence has been reported on the specific health benefits of flavonols. Apple skin is one of the richest sources of flavonols, particularly quercetin glycosides. The objective of this research was to determine the distribution of flavonols among the fruit skin tissues of selected 27 apple genotypes comprised of 11 commercial cultivars, 10 new breeding lines, and 6 crab species. An ultrasound-assisted method was optimized for extraction of flavonols from freeze-dried apple skin tissues. The identification and quantification of six known flavonols was performed using ESI-MS/MS in multiple reaction monitoring mode. The major flavonols identified in apple skins were quercetin-3-galactoside, quercetin-3-rhamnoside, quercetin-3-glucoside, and quercetin-3-rutinoside. Quercetin-3-galactoside, the most abundant flavonol, represented 46% of total flavonols in the skin. The commercial cultivar group had higher total flavonols (121 to 363 mg/100g DW) than the new breeds and crab apple groups (p<0.0001). Empire (363 mg/100g DW), Novamac (356 mg/100g), and Royal Gala (303 mg/100g DW) cultivars had the highest total flavonols content among the tested apple genotypes. Precursor ion scan of the quercetin aglycone (m/z 301) revealed the presence of an additional quercetin glycoside in some apple genotypes. Further analyses are being performed to elucidate the structure of this unknown quercetin glycoside.
Key words: Malus domestica, phenolics, flavonoids, quercetins, LC-MS/MS
P116 Life cycle analysis of environmental technologies to improve wild blueberry production. G. Dias1*, L. Bushi1, S. Young1, C. Monreal2, D. Percival3, G. Thiessen3, 1GHGm.com, Guelph, ON, N1H 4W8, 2Agriculture and Agri-Food Canada, Ottawa, ON, K1A 0C6, 3Department of Environmental Sciences, Nova Scotia Agricultural College, Truro, NS.
A Canadian agricultural life cycle analysis model was used to analyze the environmental performance of leading edge environmental monitoring and precision farming techniques to optimize fertilizer, pesticide, and water use in wild blueberry production. These techniques could provide sustainable technologies to reduce the risk of soil and water contamination and increase the competitiveness of the blueberry industry. The baseline industry practice involves standard fertilization and pesticide application at a single rate (i.e. blanket application) and limited use of irrigation. The life cycle analysis compared the environmental performance of the new technology and the baseline based on a reference unit (RU) of 1000 kg blueberries harvested. The use of precision farming techniques and environmental monitoring to determine the needs of the blueberry crop resulted in environmental savings of 1744 MJ/RU of energy, 127 kg CO2e/RU of greenhouse gases, and 580 µg/RU of ammonia emissions, compared to the baseline practice. Other environmental indicators that were measured include residual N, P loading reduction, pesticide hazard reduction, soil carbon, soil erosion reduction, and biodiversity, but these results are pending. Precision farming technologies should improve yields, fruit quality and composition and enhance environmental stewardship.
Key words: life cycle analysis, precision farming, environmental performance, blueberry production
P117 Delineation of within-site terroir effects using soil and vine water measurement. Investigation of Cabernet Franc. Javad Hakimi Rezaei* and Andrew G. Reynolds, Cool Climate Oenology and Viticulture Institute, Brock University, St. Catherines, Ontario.
The influence of soil, climate, and water status were studied in commercial vineyard blocks of Vitis vinifera L. cv. Cabernet Franc in Niagara Peninsula, Ontario. Vine performance, berry, must and wine composition of nonirrigated grapevines were compared in ten vineyard blocks containing different soil types. The influence of climate was assessed using maximum and minimum temperature, degree days (base of 10°C) and rainfall for 2005. Preliminary results showed that within each vineyard block water stress zones can be identified on GIS generated maps using leaf water potential and soil moisture measurements. Some of the variables correlated with the intensity of vine water stress. Wines made from high and low water stress zones in each vineyard block were tasted by a panel that could be differentiated in terms of water stress levels as well as geographic location.
Key words: grape water stress wine quality vine performance
P118 Effect of Plant Growth Regulators on Tomato Plug Plant Production, Field Establishment, Maturity, Yield & Quality. John Zandstra1*, Dr. Jim Dick2, John Lang3, 1Ridgetown College, University of Guelph, Ridgetown, ON N0P 2C0, 2Tomato Solutions, 23264 Mull Rd., Chatham ON, N7M 5J4, 3CanGro759 Wellington St Dresden ON N0P 1M0.
Managing transplant development in a greenhouse can be challenging in certain years, and techniques to help control plant growth would be useful. Given the limited growing season in southwestern Ontario, processing tomato transplants which establish and begin to grow quickly after transplanting are also desired. Triazoles are a group of agricultural chemicals which were initially developed as fungicides but were also found to regulate plant growth. The most typical plant growth response to triazoles is a reduction in stem length, but they also have been found to increase leaf thickness, stem thickness, and root development. Triazoles have also been reported to protect plants from environmental stresses, including drought and temperature extremes. When applied to processing tomato transplants as a soil drench at the 2 leaf stage, the triazoles paclobutrazol (Bonzi) and uniconazole (Sumagic) reduced plant development resulting in the need to fertilize heavily (up to 5 times the normal rate) to achieve the desired plant height at transplanting. These treatments resulted in increased vigour in the field (measured as plant dry and fresh weight), advanced plant development (earlier bloom), and advanced fruit maturity.
Key words: tomato transplant triazole maturity greenhouse
P119 Evaluation of fresh and aged clam processing wastes as agricultural liming agents for coastal vegetable production fields. Josée Owen1*, Serge LeBlanc1, Patrick Toner2 and Erica Fava1, 1Agriculture and Agri-Food Canada, Atlantic Food and Horticulture Research Centre, Senator Hervé J. Michaud Research Farm P.O. Box 2069, Bouctouche, New Brunswick, Canada E4S 4J1, 2New Brunswick Department of Agriculture, Fisheries and Aquaculture, 850 Lincoln Road, Fredericton, New Brunswick, Canada E3B 9H8.
Clam processing in Atlantic Canada generates 4000 metric tons of clamshell wastes annually. Twenty-year stockpiles of shells must now be remediated to satisfy environmental regulations. This study examined fresh and aged clamshells as agricultural liming agents for sandy, acidic, coastal vegetable production soils. Clamshell wastes fresh from processing and aged stockpiled shells were analysed for coliform bacteria, plant nutrients, calcium carbonate equivalent, and organic matter. The shells met New Brunswick's guidelines for wastes as soil additives. Clamshells were ground to three size fractions (<0.250 mm, 0.250 to 1.00 mm, 1.00 to 2.00 mm). These were mixed with two soils at four rates, and placed in a control-plus-factorial (commercial agricultural lime as control) pots experiment. During an eight-week incubation, soil water pH and electrical conductivity (EC) were monitored biweekly. At four and eight weeks, a soil extract germination test was conducted using watercress (Lepidium sativum L.), a species sensitive to water quality, as an indicator plant. The pH and EC data were used to develop prediction graphs of the soil reactions which can be used as a basis for guidelines for rates of land application for liming. Clamshell amendment did not negatively affect germination of watercress seeds.
Key words: clam, lime, soil pH, soil electrical conductivity
P120 Leaf removal and prohexadione-calcium can modify Camarosa strawberry nursery plant morphology for plasticulture fruit production. J.Y. Reekie1*,3, P. R. Hicklenton1, J. R. Duval2, C. K. Chandler2, and P. C. Struik3, 1Atlantic Food and Horticulture Research Centre, Agriculture and Agri-Food Canada, Nova Scotia, Canada B4N 1J5; 2Gulf Coast Research and Education Center, University of Florida, 14625 County Road 672, Wimauma, FL 33598, USA, USA; and 3Department of Plant Sciences, Crop and Weed Ecology Group, Wageningen University, Wageningen, the Netherlands.
Mowing and the application of a new gibberellin biosynthesis inhibitor, prohexadione-calcium (ProCa), were studied as methods to modify the bare-root transplant morphology of Camarosa strawberry (Fragaria × ananassa Duchesne) in a Nova Scotia nursery. The effect these nursery practices had on fruit production in annual hill plasticulture was also determined. In one experiment Camarosa plants were sprayed with ProCa at an active ingredient concentration of 62.5 mg L-1 on Aug. 22, Sep. 05, or Sep.19, 2001 and 2002, corresponding, respectively, to growing degree days (10°C base) of 800, 894 and 965 in 2001 and 726, 821 and 908 in 2002. Application on Aug. 22 increased production of daughter plants, especially those of marketable size, by increasing the number of daughters per meter of runner and allocating more dry matter to marketable daughters. In a second experiment, field plots were mowed and/or treated with ProCa at an active ingredient concentration of 62.5 mg L-1 on Sep. 05 or Sep. 19, 2001 and 2002. All plants were dug in early October, shipped to Dover, Florida, and transplanted into plasticulture for fruit production. At digging, plants that had been mowed or treated with ProCa on Sep. 05 were reduced in plant height and total leaf area compared with untreated plants. Plants that were treated both with ProCa and mowed were the shortest. Fruit yield was higher from treated than from untreated plants. In 2001, the treatments increased early fruit production.
Key words: Fragaria x ananassa, mowing, gibberellin biosynthesis inhibitor, phenology, height control
P121 Time to Emergence (ATE) and Stem Number of Potato Plants grown from Seed Tubers Treated with Ethylene and 1 - methylcyclopropene (MCP) During Storage. K. Pruski*, B. Daniels-Lake and R. Prange. Nova Scotia Agricultural College, 50 Pictou Rd., Truro NS, B2N 5E3; Atlantic Food & Horticulture Research Centre, Kenville NS, B4N 1J5.
A three-year study (2002/04) was undertaken to determine the effects of low concentrations of ethylene in storage atmosphere and MCP (1-methylcyclopropene) treatment on physiological responses of seed tubers. Seed tubers (cut and uncut) of the three cultivars, Atlantic, Russet Burbank and Shepody, were stored at 4 °C, 80 - 85% humidity, with air ventilation of 15 L/min for two -6 h periods daily, either under continuous ethylene supplement at 4 ppm alone (either from November or February) or with MCP, applied as a gas, for 48 h, only once in early December. In growth-room studies, once a month (January - May), six uncut tubers were taken from each of the storage treatments, planted to pots and grown for one month at 16 h photoperiod, 22/18°C d/n temp. In field studies, cut (stem and rose end) and uncut tubers were planted. In the growth-room, shoot emergence from the ethylene-treated seeds of all three cultivars occurred significantly earlier (up to 5 days), producing higher number of stems per tuber and stolons per stem, compared with control and MCP treatments. ATE decreased further with the increased length of storage. MCP in combination with ethylene was particularly effective in Shepody after 190 days of storage. Similar in the field, plants grown from ethylene-treated whole and cut rose end seed emerged earlier (2-3 days) compared to plants from untreated and cut stem end seed. In the field, however, the differences between cultivars were more pronounced than in growth-room studies.
Key words: potato, tuber size control, time to emergence, stem count, storage
P122 Do Photo-Physical-Mechanical (PPM) pre-treatments induce defense against carrot blights (Alternaria dauci and Cercospora carotae) through endogenous hormonal signals? Kathryn Pickle1*, Rajasekaran R. Lada1, Sam Asiedu1, Claude Caldwell1, Jeffrey Hoyle2, and Jeffrey Norrie3, 1Department of Plant and Animal Science, Nova Scotia Agricultural College, PO Box 550, Truro, NS, B2N 5E3, 2Department of Environmental Science, Nova Scotia Agricultural College, PO Box 550, Truro, NS, B2N 5E3, 3Acadian Seaplants Limited, 30 Brown Avenue, Dartmouth, NS, Canada, B3B 1X8.
Plants have evolved many different and ingenious strategies to defend themselves against environmental and biotic stresses. The impact of examining and understanding these natural defense mechanisms may lead to the modification of conventional farming practices, and reduce our dependency on chemical disease control. One of the most promising methods is to trigger plant defenses by exposing them to an abiotic stress prior to infection, thereby increasing the plants resistances to diseases and/or pests. In this model study, UV-C radiation, leaf brushing and canopy trimming were applied to field-grown carrots and the degree of blight and white mold infection was measured. Preliminary analyses showed that UV-C radiation at 4 weeks post-emergence or brushing at 4 or 8 weeks significantly reduced carrot blight and/or white mold. This implies that UV-C radiation and brushing may induce plant defenses, allowing the crop to better defend itself against future biotic stress. This hypothesis that photo-physical and mechanical (PPM) pre-treatments induce plant defenses through increasing endogenous salicylates and/or jasmonates is being investigated under controlled conditions.
Key words: photo-physical, mechanical, plant defense mechanisms
P123 Prince Edward Island growers can reduce soil phosphorus buildup while maintaining carrot crop yield. K.R. Sanderson* and J.B. Sanderson, Agriculture and Agri-Food Canada, Crops and Livestock Research Centre, Charlottetown, PE Canada C1A 4N6.
Producers continually manage the application of nutrients relative to economic crop returns while remaining sensitive to environmental issues such as increasing soil phosphorus. To address this issue in carrot production, we studied the effect of soil applied P on yield and soil P content in PEI. Six field studies over a three-year period were evaluated to determine the yield response of carrot (Daucus carota L.) on sandy to loamy sand Orthic Podzol soils. Treatments consisted of broadcast P at 0, 33, 66, 99 and 132 kg P ha-1. When total yield of carrots was fitted to a quadratic response curve and solved for maximum yield, 110 kg P ha-1 would be required to achieve this yield. By applying P to achieve 95% of maximum yield, soil test P was only increased by 25% compared to when P was applied to achieve maximum yield. Carrot growers can significantly reduce environmental contamination caused by the buildup of soil P while maintaining excellent crop yield.
Key words: Carrots, phosphorus, yield, soil P
P124 Assessing nitrogen use efficiency and potential nitrogen losses in field-grown cucurbits. Laura L. Van Eerd*, University of Guelph, Ridgetown Campus, Ridgetown, Ontario N0P 2C0.
With nutrient management legislation, it may be more critical to optimize nitrogen use efficiency (NUE) in order to maintain crop yields and minimize off-field N losses. The aforementioned parameters were assessed over two years in three field experiments of processing winter squash and machine-harvested processing cucumbers. Preplant ammonium nitrate or UMAXX® (a urea-based fertilizer containing nitrification and urease inhibitor) was broadcast applied at five doses between 0 and 220 kg N/ha, and a split application of 70 plus 40 kg N/ha. In two contrasting years (i.e. cool/wet vs. warm/dry), marketable cucurbit yield response to N application was either positive, negative, quadratic, or no response. There was no difference in marketable yield between different application timings nor N source. Generally, NUE decreased as N rates increased from 110 to 220 kg N/ha for both cucurbits. Squash NUE was considerably higher than cucumber, which was likely due to the stage of plant development at harvest. The quantity of mineral N remaining in the field at harvest varied greatly with location and cucurbit crop. Preliminary results indicate an opportunity to reduce N rates and thus increase NUE and decrease potential N losses.
Key words: vegetable, nitrogen, squash, cucumbers
P125 Effects of Summer and Fall Applications of Foliar Boron on Wild Blueberry Fruit Bud Winter Injury. L.J. Eaton1*, H-Y. Ju1 and K.R. Sanderson2, 1Nova Scotia Agricultural College, Truro, N.S. B2N 5E3, 2Agriculture and Agri-Food Canada, Crops and Livestock Research Centre, Charlottetown, P.E.I. C1A 4N6.
Boron is a micro nutrient that is important in small fruit production, and plays a role in fruit bud development and possibly in tolerance of harsh winter conditions. Boron is applied to a few wild blueberry (Vaccinium angustifolium Ait.) fields in Nova Scotia, but little is known of its effects. This study reports the effects of single and multiple applications of foliar boron to two commercial wild blueberry fields, particularly the effects on tissue B concentrations and winter injury to developing fruit buds. Foliar boron (Bortrac®) was applied in single and multiple applications over a four year period. Multiple foliar boron applications, summer + fall, resulted in increased tissue boron levels in first crop fruit buds compared to untreated controls, but the increases were not observed in second crop fruit buds. Only multiple applications of foliar boron (summer + fall) applied in two successive cycles at the Fern Walker field reduced winter injury compared to untreated controls. It is possible that multiple foliar applications of boron to blueberry fields may reduce winter injury to developing fruit buds in some years.
Key words: boron, micro-nutrient, winter injury, tissue boron levels, wild blueberry
P126 Influence of Introduced Living Mulches in Lowbush Blueberry Fields on Soil Microclimatic Conditions. Lynda I. Stewart*, David C. Percival, and Bonna L. Jordan, Department of Environmental Sciences, Nova Scotia Agricultural College, Truro, Nova Scotia, Canada B2N 5E3.
Increased herbicide use has lead to an increase in the size and number of bare spots in fields and soil erosion creating an unfavorable environment for wild blueberry growth and development. Vegetative cover, in the form of living mulches, is a feasible method of improving soil quality and lowbush blueberry coverage. Two experiments were conducted in commercial blueberry fields to determine the effects of introducing living mulches on the soil microclimatic conditions, and the competition for light between the blueberry and living mulches. Both experiments were established in the vegetative phase of production and each consisted of three vegetative treatments. The first experiment consisted of 1) an unseeded control, 2) creeping red fescue and perennial ryegrass, and 3) birdsfoot trefoil (BFT) and tall fescue. The second experiment consisted of 1) an unseeded control, 2) BFT, perennial rye grass, tall fescue, and 3) nordic hard fescue, sheep's fescue, creeping red fescue, perennial ryegrass. Following two growing seasons, the living mulches significantly retained soil moisture and decreased soil temperature when compared to the bare soil samples. The introduction of the living mulches did not affect the soil hydraulic activity, infiltration rate, or soil aggregate stability. BFT and fescue species significantly increased the % organic matter and the soil nutrients K, Ca and Mg. LAI and PAR results suggest the fescue species compete less for light, and may be more suitable as living mulches in lowbush blueberry fields.
Key words: Lowbush blueberry, living mulch, fescue species, birdsfoot trefoil
P127 Microbial growth control of fresh-cut apples by cinnamon extracts. S. Muthuswamy*, H.P.V. Rupasinghe, and G.W. Stratton, Department of Environmental Sciences, Nova Scotia Agricultural College, Truro, Nova Scotia B2N 5E3, Canada.
The consumer demand for convenient and nutritious minimally processed produce like fresh-cut apple has been steadily increasing. Identification of natural antimicrobial agents that are acceptable to consumers is a challenge to the fresh-cut industry. We have investigated the potential for natural antimicrobial products extracted from cinnamon (Cinnamomum cassia) to use as a food additive to extend the shelf life of fresh-cut apples. Five extracts were prepared from cinnamon bark and powder to evaluate their antimicrobial activity on two common food borne microorganisms, Escherichia coli and Listeria innocua. An ethanolic extract of cinnamon bark inhibited the growth of E. coli and L. innocua by 67 and 68%, respectively, as determined by the optical density (turbidity) of the Tripticase soy broth (TSB) culture medium (24 hrs at 32C) inoculated with the microorganisms separately. When incorporated in a commercial anti-browning dipping solution FreshExtendTM, the cinnamon extract reduced significantly (p<0.05) the microbial growth of apple slices stored for 12 days at 6C in comparison to the control. The cinnamon extract had no influence on the antibrowning properties of FreshExtend. Liquid chromatography mass spectrometry analysis showed that the major component of this extract is cinnamaldehyde.
Key words: Malus domestica, minimally-processed, natural antimicrobial, shelf life
P128 Ambiol enhances drought tolerance in flacca tomato mutant with wilty phenotype. Mason T. MacDonald*, Ecophysiological Research Group, Department of Plant and Animal Science, Nova Scotia Agricultural College, Truro, NS, B2N 5E3.
Ambiol is a synthetic antioxidant well established to possess plant growth regulating properties. In addition, Ambiol is capable of alleviating drought stress in a variety of dicots and conifers, including tomatoes (Lycopersicon esculentum). As such, it is expected that Ambiol may require ABA, a phytohormone associated with stomatal closure, to alleviate drought stress. A 2-sample t-test was constructed to test the effect of a 10 mg L-1 and 0 mg L-1 Ambiol seed treatment on an ABA deficient tomato mutant, flacca. It was found that the 10 mg L-1 treatment was able to significant increase plant height (10%), membrane stability (10%), and photosynthetic rate (60%). These preliminary results suggest that there is some benefit from Ambiol regardless of the presence of ABA, perhaps due to promotion of cytokinins or auxins , which would help explain increased growth and stability of the photosynthetic apparatus. Confirmatory studies are needed using ABA inhibitors.
Key words: Ambiol, benzimidazole, drought, stress, flacca
P129 Impact of morphological and physiological variations in strawberries (Fragaria) on resistance to he tarnished plant bug, Lygus lineolaris, and the efficacy of the egg parasitoid, Anaphes iole. Nader Koohpayehzadeh1*, Guy Boivin2, Yves Desjardins1, Shahrokh Khanizadeh2, 1Université Laval, Département de Phytologie, 2HRDC, Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu QC, Canada, J3B 3E6.
The strawberry is one of the most important small fruit culture in Canada. There are hundreds of strawberry varieties which were developed based on morphological traits as well as physiological factors. Moreover, these varieties vary in their susceptibility to some diseases and pests. The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hem.:Miridae) is an important pest of strawberries causing fruit deformation " catfaced " and abortion. In this study, we will assess the important of morphological and physiological characteristics of strawberry in the resistance of this plant to the tarnished plant bug. However, in order to use resistant cultivars of strawberries in integrated pest management programs, it is important to determine the effectiveness of natural enemies on these cultivars. To verify this hypothesis in the strawberry system, we will use Anaphes iole Girault (Hym.: Mymaridae), an egg parasitoid of tarnished plant bug. These results will help plant breeders to produce cultivars which are both resistant to this pest and amenable to the use of egg parasitoid.
Key words: Strawberry, tarnished plant bug, Lygus, Anaphes iole, resistance
P130 SuperMac, a new winter hardy scab resistant apple cultivars. Shahrokh Khanizadeh1*, Yvon Groleau1, Audrey Levasseur1, Odile Carisse1, Jennifer DeEll2, Jean-Pierre Privé3, Campbell Davidson4, Intiaz Ali5, Jenk Kemp6,1Agriculture and Agri-Food Canada, Horticultural Research and Development Centre, 430 Gouin Blvd., St-Jean-sur-Richelieu, QC, Canada, J3B 3E6, 2Ontario Ministry of Agriculture and Food, Box 587, 1283 Blueline Rd & Hwy #3, Simcoe, Ontario, Canada N3Y 4N5, 3Agriculture and Agri-Food Canada, Food and Horticulture Research Centre, Senator Hervé J. Michaud Research Farm, 1045 St. Joseph Rd. Bouctouche, NB, Canada, 4Agriculture and Agri-Food Canada, Cereal Research Centre, Unit 100 - 101 Route 100; Morden, MB, Canada, R6M 1Y5, 5Department of Food Science, Macdonald Campus of McGill University, 4,111, Lakeshore rd. Ste Anne de Bellevue, Quebec and 6Praktijkonderzoek Plant & Omgeving B.V., Postbus 167, 6700 AD Wageningen, The Netherlands.
SuperMac is being released as a replacement for Spartan, which is presently being grown in Eastern Canada for its excellent shelf life but susceptibility to scab the most common apple diseases. This new cultivar produces larger fruit than 'partan and is resistant to apple scab (Venturia inaequalis (Cke) Wint.). It is very attractive, has a pleasant taste and an excellent shelf-life and keeps very well and longer compare to the "Spartan'. SuperMac is a 'McIntosh' type apple (Malus x domestica Borkh. The tree is hardy to -30oC, and the fruit and leaves are resistant to the common races of apple scab (Venturia inaequalis (Cke) Wint.) due to the presence of the Vf gene derived from Malus floribunda 821.
Key words: Malus, Venturia inaequalis, breeding, genetic
P131 Eden(TM) A Non-Browning Apple Cultivar. Shahrokh Khanizadeh1*,Yvon Groleau1, Audrey Levasseur1, Rong Tsao2, Raymond Yang2, Jennifer DeEll3, Cheryl R. Hampson4 and Peter Toivonen4, 1Agriculture and Agri-Food Canada, Horticultural Research and Development Centre, 430 Gouin Blvd., St-Jean-sur-Richelieu, QC, Canada, J3B 3E6; 2Agriculture and Agri-Food Canada, Food Research Centre, 93 Stone Road West, Guelph, ON, Canada, N1G 5C9; 3Ontario Ministry of Agriculture, Food and Rural Affairs, 4890 Victoria Ave N, Box 8000, Vineland Station, ON, Canada, L0R 2E0; 4Agriculture and Agri-Food Canada, 4200 Hwy. 97, Summerland, BC, Canada, V0H 1Z0.
Eden (TM) is a dessert apple (Malus x domestica Borkh.) type with improved firmness, crispness, high quality flesh and much longer shelf life than McIntosh and Cortland. The fruit have superior flavor and do not fall from the tree at maturity. The flesh is juicy, firm, crisp and resistant to bruising. No browning occurs after cutting, making it an excellent candidate for fresh fruit slices, fruit salad, dried apple chips and processing (juice, cider). Eden (TM) also tested as 'SJCA38R6A74' and 'A38R6A74', originated from a cross made in 1971 between Linda and Jonamac, at the Agriculture and Agri-Food Canada (AAFC), Horticultural Research and Development Center (HRDC). 'Eden(TM)' fruit are susceptible to bitter pit, especially if the season is dry and no irrigation is provided. The yield is very similar to Macspur and the fruit are resistant to water core. Contrary to Macspur, the fruit of Eden do not drop at maturity and stay on the tree several weeks after, even at -20oC, which make it a good candidate for Ice Cider production.
Key words: 'SJCA38R6A74' (EdenTM) Apple, Additional index words: Malus x domestica, fruit breeding, winter hardy, antioxidant, long shelf life, non-browning apple, Persistent fruit
P132 Antioxidant Capacity in June-bearing and Day-Neutral Strawberry. Shahrokh Khanizadeh*, Behrouz Ehsani-Moghaddam, and Audrey Levasseur, Agriculture and Agri-Food Canada, Horticultural Research Development Centre, 430 Gouin Blvd., St-Jean-sur-Richelieu, Québec, Canada, J3B 3E6.
The present study was carried out to estimate the crude, hydrophilic and lipophilic antioxidant content of known and new advanced selections among June-bearing and day-neutral genotypes using Trolox equivalent antioxidant capacity method. Crude, hydrophilic and lipophilic extractions were prepared using 25g samples of frozen fruits. In June-bearing strawberries, significant differences were observed among crude, hydrophilic and lipophilic antioxidant values of different selected genotypes. Mean of crude, hydrophilic and lipophilic antioxidants in June-bearings were estimated 20.382, 13.444 and 0.474 µmol TE/g FW, respectively, which were higher than those of the day-neutral genotypes (i.e. 13.167, 9.387 and 0.281 µmol TE/g FW). The present study revealed the importance of genetic background for determining the antioxidant potential in selected June-bearing genotypes and the possibility of production of new strawberry cultivars with higher levels of antioxidant capacity through breeding programs.
Key words: antioxidant, Trolox, phenolics, shelf life
P133 Clé des Champs Strawberry. Shahrokh Khanizadeh1*, Martine Deschênes1, Audrey Levasseur1, Odile Carisse1, Jennifer DeEll3, Rong Cao2, Raymond Yang2, J. Alan Sullivan4, Jean-Pierre Privé5, 1Agriculture and Agri-Food Canada, Horticultural Research and Development Centre, 430 Gouin Blvd., St-Jean-sur-Richelieu, QC, Canada, J3B 3E6; 2Agriculture and Agri-Food Canada, Food Research Centre, 93 Stone Road West, Guelph, Ontario, Canada, N1G 5C9; 3Ontario Ministry of Agriculture and Food, Box 587, 1283 Blueline Rd & Hwy #3, Simcoe, ON, Canada, N3Y 4N5; 4Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada, N1G 2W1; 5Agriculture and Agri-Food Canada, Food and Horticulture Research Centre, Senator Hervé J. Michaud Research Farm, 1045 St. Joseph Rd. Bouctouche, NB, Canada.
Clé des Champs is a new June bearing strawberry cultivar (Fragaria X ananassa Duch.), bred for Eastern Central Canada and climates similar to Quebec conditions. Clé des Champs was released for pick your own and shipping because it has very attractive light red, glossy and firm fruit, which have an excellent shelf life of several days. Clé des Champs, tested as LL9324-24, is a progeny resulting from a cross between 'SJ89244-6E' and 'SJ8518-11' made in 1993 by S. Khanizadeh. Clé des Champs has been tested at the Agriculture and Agri-Food Canada (AAFC) sub-station in L'Acadie, Quebec since 1994, and during 1995-2002 by our partners Association des producteurs de fraises et framboises du Québec - (APFFQ) and Réseau d'Essais de Petits Fruits, CPVQ (Quebec Regional small fruit trials, Conseil des productions végétales du Québec) in Quebec. It has been also tested by other AAFC research centers (Atlantic Food and Horticulture Research Centre, Bouctouche NB), as well as in Ontario. Clé des Champs is presently being tested in another AAFC research center (Manitoba) and also in Europe by Meiosis (Bradbourne House, Stable Block, East Malling, Kent ME19 6DZ).
Key words: winter hardy, fragariae, genetics
P134 Phenolic Composition and Antioxidant Activity of Selected Apple Genotypes. Shahrokh Khanizadeh1*, Rong Tsao2, Djamila Rekika1, Raymond Yang2 and Jennifer DeEll3, 1Horticultural Research and Development Centre, Agriculture and Agri-Food Canada, 430 Gouin Blvd., St-Jean-sur-Richelieu, Quebec, Canada, J3B 3E6; 2Food Research Program, Agriculture & Agri-Food Canada, 93 Stone Road West, Guelph, Ontario N1G 5C9, Canada; 3Ontario Ministry of Agriculture and Food, Box 587, 1283 Blueline Rd & Hwy #3; Simcoe, ON, Canada, N3Y 4N5.
The phenolic composition of eleven apple genotypes was determined in the flesh and peel by high performance liquid chromatography (HPLC), total phenolic content (TPC) by the Folin-Ciocalteu method, and antioxidant capacity using ferric reducing antioxidant power (FRAP). HPLC analysis identified and quantified several groups of phenolic compounds: procyanidins, hydroxycinnamic acids, anthocyanins, flavonols, and dihydrochalcones. Procyanidins were the most predominant group in both flesh and peel and contributed 52.4% and 44% of the total phenolic index (TPI), respectively. Quercetin glucosides were almost exclusively found in the peel, while cyanadin 3-galactoside was found only in red apple peel. The profile of phenolic compounds varied among the eleven genotypes and the peel showed higher concentrations than the flesh. Among the studied genotypes Reinette Russet and 'SJCA38R6A74' had the highest and the lowest concentrations, respectively. The total phenolics (TPI/TPC) of both flesh and peel extracts correlated well with antioxidant capacity as estimated by the FRAP assay (R2 = 0.87, 0.76, 0.92, respectively), with the exception of TPC from the apple peel determined with FC (R2 = 0.52). The low chlorogenic acid and zero total flavanol content in flesh of 'SJCA38R6A74' genotype tended to be associated with no browning compare to other cultivars.
Key words: Malus, Phenolics, scab resistant
P135 Fresh market sweet corn production under clear and solar mulch films. T.Q. Zhang*, C.S. Tan, and J. Warner, Harrow Research Center, Agriculture & Agri-Food Canada.
Earliness of fresh market sweet corn is vital important to increase production profitability and maintain market occupancy. The maturity of fresh market sweet corn may be advanced by various mulch films, which however have to be screened to select the one that maximizes the earliness and productivity. We conducted an experiment to determine the effects of clear (CMF) and solar mulch films (SMF) on soil temperature and moisture during the growing season and the performance of fresh market sweet corn in a Granby sandy loam soil with and without N fertilization in southwest Ontario from 2000 to 2001. Regardless of N fertilization, both mulch films increased soil temperature and moisture, compared with the bare soil. Increases of soil temperature were greater under CMF than SMF, with an average of up to 2.2oC across the entire growing season in both 0-10 and 10-20cm soil depths. However, increases of soil moisture (0-20cm) were up to 4.4% less under CMF than SMF. Both CMF and SMF advanced sweet corn maturity by 6-7 days. Marketable yield increased by 25 to 63% without N addition and by 72 to 114% with N addition under CMF. Under SMF, marketable yield increased by 97 to 98% without N addition and by 120 to 200% with N addition. SMF is significantly superior to CMF for fresh market sweet corn production.
Key words: sweet corn, mulch film, maturity, yield, soil temperature, soil moisture
P136 Protocol for Explant Disinfection and in vitro Shoot Multiplication in Rhubarb. U. Rayirath1*, R. Lada1, C. Caldwell1, S.K. Asiedu1 and K. Sibley2, 1Department of Plant & Animal Sciences, 2Department of Engineering, Nova Scotia Agricultural College, Truro, Nova Scotia, Canada, B2N 5E3.
Rhubarb (Rheum rhabarbarum L.) is an emerging commercial vegetable having great potential or the frozen food industry in North America. However, the exorbitant propagule cost and low rate of in situ propagule production limit expansion of rhubarb industry. Rhubarb is propagated vegetatively by rhizome divisions. Identifying rhizome growth accelerating signals and their application will increase propagule production. Experiments are being conducted to identify the rhizome inducing signals in rhubarb in vitro. Experiments were conducted to standardize protocols for explant disinfection and rapid in vitro shoot multiplication from meristem tips. The results showed that treating lateral bud explants with 30 % bleach (sodium hypochlorite) for 10 minutes significantly reduced culture contamination. The culture medium containing MS basal salts and 1 mg/L each of benzyl aminopurine (BAP) and indole 3- butyric acid (IBA) was found to be ideal for rapid shoot multiplication from meristem tips. The protocol is successfully used for inducing multiple shoots from meristem tips obtained from lateral buds.
Key words: in vitro, protocol, rhubarb, disinfection, shoot- multiplication
P137 Polyphenol profiles of apple processing by-products. H.P. Vasantha Rupasinghe*, Nova Scotia Agricultural College, Department of Environmental Sciences, Truro, Nova Scotia B2N 5E3 Canada.
There is a strong body of scientific evidence indicating the role of plant polyphenols in fruits and vegetables for their potential benefits in human health. Processing of apples for juice, pie and sauce results in significant volumes of by-products such as pomace, skins, cores, and seeds. The purpose of this study was to investigate whether the processing waste streams of apple are a promising source for biologically active polyphenols. Liquid chromatography coupled to electrospray ionization and triple quadrupole mass spectrometry (ESI-MS/MS) was used to determine the polyphenols present in apple by-products collected from commercial juice and pie manufacturing plants. Apple pomace contained total phenols content of 43 mg/100g dry weight (DW). The most predominant phenolic compound present in apple seeds and cores was phloridzin (64 and 24 mg/100g DW, respectively). The total phenolic contents of skin tissues of 'Northern Spy' and 'Idared' cultivars were 322 and 402 mg/100g DW, respectively. Among the major polyphenols of 'Idared' skins were: cyanidin-3-galactoside (114 mg/100g DW); quercetin-3-galactoside (90 mg/100g DW); phloridzin (56 mg/100g DW); chlorogenic acid (40 mg/100g DW); and epicatechin (33 mg/100g DW). These findings demonstrate the potential nutraceutical and other uses of apple by-products upon the investigation of efficient extraction technologies.
Key words: Malus domestica, phenolics, flavonoids, by-products, LC-MS/MS
P138 Preemergence Weed Control in Ornamental Perennials. Valtcho D. Zheljazkov1*, Kevin Patterson2, Kim Parsons2, and Glen Sampson2, 1Mississippi State, North Mississippi Research and Extension Center, 5421 Highway 145 South, Verona, MS 38879, U.S.A. Tel: (662) 566-2201 Fax: (662) 566-2257, 2Department of Environmental Science, Nova Scotia Agricultural College, P. O. Box 550 Truro, Nova Scotia B2N 5E3, Canada.
In recent years, the market for ornamental perennials (such as Astilbe japonica, Astilbe arendsii, Astilbe chinensis, Sedum spp., Hosta fortunei, and Hemerocallis spp.) in Canada expanded. Weed competition is a major limiting factor to production of these new cash crops. The objective of this two-seasons field study was to evaluate pre-emergence and post-emergence herbicides for weed control in the above ornamentals. It was found that: (1) Pre-emergence herbicides: (1.1) Napropamide, linuron, mebribuzin, pendimethalin, metolachlor, pronamide, and oxyfluorfen may be used in Hosta. (1.2) For weed control in Astilbe, napropamide, pendimethalin, metolachlor, pronamide, and oxyfluorfen may be suitable. Linuron at 2.25 kg a.i. ha-1 can be used in A. japonica and A. arendsii, but no in A. chinensis. (1.3) Herbicides napropamide, linuron, pendimethalin, metolachlor, pronamide, and oxyfluorfen may be suitable for weed control in both Herocallis and Sedum. (2) Post-emergence herbicides: (2.1) Bentazon, fluazifop-P, pendimethalin, pronamide, thifen sulfuron, rimsulfuron, dithiopyr, and isoxaben can be used. Chlorimuron should be tested further at lower rates. (2.2) Fluazifop-P, pendimethalin, pronamide, chlrorimuron, thifensulfuron, rimsulfuron, dithiopyr, and isoxaben can be used for weed control in all three Astilbe species. (2.3) Bentazon, fluazifop-P, pendimethalin, pronamide, chlorimuron, rimsulfuron, dithiopyr, and isoxaben can be used in Hemerocallis. (2.4) Bentazon, pendimethalin, pronamide, chlorimuron-ethyl, nicosulfuron, nico-rimsulfuron, thifensulfuron, dithiopyr, and isoxaben can be used in Sedum.
Key words: Bare root perennials, Screening of herbicides, Astilbe, Sedum, Hosta, Hemerocallis
P139 Incubation PRSTM-N flush on organic highbush blueberries (Vaccinium corymbosum L.) soils with and without mulches. Zhiming Zheng1*, Derek H. Lynch1, David Percival2, and Nicole Burkhard1, 1Department of Plant and Animal Sciences, 2Department of Environmental Science, Nova Scotia Agricultural College, P.O. Box 550 Truro, NS B2N 5E3.
Previous studies have indicated a poor relationship between standard soil N tests and highbush blueberry plant N uptake. Standard leaf N tests are conducted too late in the season for making current season N recommendations, and this is especially true for organic highbush blueberries where supplemental fertilization is reliant on slowly mineralizing organic amendments. Ion exchange membranes may provide an alternative tool to assess the N supply power of these soils. The study was designed to assess the mineral N flush on unfertilized highbush blueberries soils under laboratory incubation. In the Spring of 2005, soils were taken from 2 sites varying in texture of Nova-Agri/Blueberry Acres, a commercial organic highbush blueberry farm, in Centreville, NS. Both mulched and un-mulched mineral soils were recovered, sieved to pass 6 mm sieve and air-dried. In the Spring of 2006, a pot study was conducted using mulched and unmulched mineral soils under a controlled air temperature (25 °C) and a soil moisture of 60% field capacity. A pair (cation/anion) of Plant Root Simulator (PRSTM) probes, an ion-exchange membrane encapsulated in a plastic probe was inserted into soils in each plot. The probes were replaced at intervals of 3d at first, followed by 4 successive 7d periods thereafter over a total of 31d. The mineral N sorbed on probes (PRS-NO3 and -NH4) was eluted with 0.5M HCl and determined colorimetrically by a hydrazine-reduction method. A subsample of soil (~50g) was also taken at day 0 and 31 for determination of soil mineral N (NO3-N and NH4-N) content by chemical extraction. The relationships between the flush of mineralized soil N over a defined summative burial period and soil mineral N measured by chemical extraction as affected by soil texture and mulches will be examined.
Key words: incubation, organic highbush blueberries, Plant Roots Simulator (PRSTM) probe, soil mineral N, soil N flush