Canadian Society for Horticultural Science

Technical Program - Tuesday July 10^th, 2001

Room 1307 Thornbrough Building  Moderator, Allan Sullivan

8:30 - 8:35 Welcome and Announcements

8:35 - 9:15 Management Strategies for Optimizing Greenhouse Vegetable Production, Shalin Khosla, (invited speaker)

9:15 - 9:50 Development of a Food Safety Program, Amber Leudtke (Invited Speaker)

9:50 - 10:10 Refreshment Break (Centre Six)

Oral Session 2. Biotech Breeding and Genetics.

Room 1307 Thornbrough Building

10:10 - 10:40 The Quebec Strawberry and Apple Breeding Programs: An Overview, Shahrokh Khanizadeh (Invited Speaker)

10:40 - 11:10 Biotechnology and Horticultural Crops, Gord Surgeoner (Invited Speaker)

Poster Session 1 & 2

11:10 - 12:00 Peter Clark Hall

Lunch

12:00 - 1:45 CSHS Annual General Meeting Luncheon (Room 1307 Thornbrough Building)

Oral Session 3. Medicinal Plants and Novel Crops

Room 1307 Thornbrough Building

2:00 - 2:30 New Medicinal Plants for Horticulture, Praveen Saxena (Invited Speaker)

2:30 - 3:00 Horticultural Plants for Phytoremediation, Thereza Dan (Invited Speaker)

3:00 - 3:15 Refreshment Break (Centre Six)

Poster Session 3.

3:15 - 4:00 Peter Clark Hall

Graduate Student Poster Judging

4:00 - 4:30 Peter Clark Hall

Annual Banquet

6:30 - 9:30 Rm1077 B&C , Ontario Veterinary College

Table of Contents

Managing Crops for Optimum Productivity and Safety

Abstracts for Poster Session 1

Poster Session 11:10-12:00

Peter Clark Hall, University Centre

CSHS Poster 1.1 Effects of Urea and Plant Bioregulators (Ethephon and Promalin) on Reserve N, Cold Hardiness, and Cropping of Sweet Cherry Trees
S. Guak*, M. Beulah and N.E. Looney

Agriculture and Agri-Food Canada, Pacific Agri-Food Research Centre, Summerland, British Columbia V0H 1Z0
  Email: guaks@EM.AGR.CA

In deciduous fruit trees, reserve N is known to play an important role in early season growth but its effect on cropping is little understood. To improve tree reserve N, we sprayed six-year-old 'Lapins'/Mazzard trees with four rates of urea (0, 2, 4 or 6%) on 25 September and 2 October, 2000. Ethephon (200 ppm) as a leaf senescence promotor and Promalin (250 ppm BA + 250 ppm GA₄₊₇) as a senescence delaying agent were combined with urea - the aim being to determine how bioregulator-altered leaf senescence/abscission affects N recovery from leaves. Each bioregulator was applied 3 days before and 3 days after the first urea spray. Urea increased total N concentrations in leaves and in dormant flower buds and twigs proportionally to rate applied. 6% urea increased total N by 15%, 19%, and 13% in leaves, buds and twigs, respectively. Ethephon advanced leaf senescence and abscission but did not alter net N recovery. In contrast, Promalin delayed leaf senescence and abscission and substantially reduced N recovery. Accordingly, Promalin significantly reduced twig reserve N. Interestingly, ethephon slightly reduced flower bud N while Promalin increased it. Urea did not affect cold hardiness of flower buds or twigs measured in early December; ethephon increased it in both tissues; and Promalin significantly decreased twig (but not bud) hardiness. The effects of these treatments on bud hardiness in early spring and year 2001 flowering and fruit set will also be reported.

CSHS Poster 1.3 Nitrogen Management and Cultivar Evaluation for Controlling Petiole Spotting and Bacterial Soft Rot of Chinese Cabbage. J. Warner*, R. Cerkauskas, T. Zhang and X. Hao Greenhouse & Processing Crops Research Centre, Agriculture and Agri-Food Canada 2585 County Road 20, East, Harrow, Ontario N0R 1G0 Email: warnerj@em.agr.ca

Chinese cabbage is one of the most extensively grown Asian vegetables in southern Ontario. Disorders such as petiole spotting (gomasho) and bacterial soft rot (Erwinia carotovora subsp. carotovora) may lead to significant losses in production and quality. The objectives of this study were to investigate the effects of nitrogen (N) source and rate on gomasho, bacterial soft rot and yield of Chinese cabbage and to identify cultivars with resistance to the disorders and which are suitable for commercial production in Ontario. Three N fertilizer sources (ammonium nitrate, urea, calcium nitrate), each applied at 100, 200 and 300 kg N/ha + a zero N treatment (10 main plot treatments) and two cultivars, Kasumi and Ohken 75 (subplot treatments) were tested. In a separate experiment, 16 Nappa type cultivars were evaluated. Cabbage head size was not affected by N source or rate. However, both source and rate of N fertilization affected the incidence of petiole spotting and bacterial soft rot, depending on cultivar. Petiole spotting severity increased after 4 weeks of storage at 2^oC. There was a range in cultivar susceptibility to both petiole spotting and bacterial soft rot. Of the cultivars tested, Akala, Spring Flavor, Yuki and Ohken 75 had relatively low petiole spotting ratings. Kasumi and Blues were very susceptible to soft rot with over 50% of the heads affected while Yuki was least susceptible with only 4% of heads affected.

A nitrogen (N) rate and source experiment was conducted on summer cabbage cultivar Atlantis on mineral soil in Simcoe, Ontario in 2000 in response to proposed nutrient management legislation. Nitrogen rates of 0, 50, 100, 150, and 200% of the recommended rate (128 kg N/ha preplant; 42 kg N/ha sidedress) were applied using calcium ammonium nitrate preplant and potassium nitrate for all sidedress applications. Potassium nitrate was also applied at 200% of the recommended N rate. In a final treatment, 50% recommended N was applied preplant and sidedresses were based on weekly chlorophyll meter readings. At three times during the growing season, the nitrogen status of the plants was analysed using a chlorophyll meter on mature leaves and a nitrate meter on midrib sap and a soil extract. Tissue and soil samples were sent to a lab for N analysis. At harvest, cabbage was graded for total yield, marketable yield, density, and thrips damage. Cabbage yield was higher in the 150 and 200% N rates than the lower N rates. Thrips damage was higher in low N treatments as a result of delayed maturity. Potassium nitrate treatments had significantly lower yields than the corresponding rate of calcium ammonium nitrate. Sidedress applications based on chlorophyll meter results were too late to recover full yield potential. Chlorophyll meter readings showed a better correlation with yield than the nitrate meter, however both show potential in nutrient management of cabbage. The results suggest current N recommendations may need to be revised. Keywords: Cabbage, nitrogen, nutrient management, thrips, chlorophyll, yield

CSHS Poster 1.5 Weed Discs and Other Nonchemical Alternatives for Container Weed Control. C. Chong* and P. Purvis, Dept. of Plant Agriculture - Vineland, University of Guelph, Vineland Station, Ontario, Canada L0R 2E0
Email: cchong@uoguelph.ca

Forsythia (Forsythia × intermedia 'Lynwood Gold'), potentilla (Potentilla fructicosa 'Pink Beauty') and weigela (Weigela florida 'Red Prince') liners were grown for one season in containers with six weed control treatments: Enviro LID and Tex-R Geodisc weed discs; Mori Guard weed sleeve; Devrinol and Ronstar herbicides applied at potting; and both herbicides applied at potting plus Ronstar only six weeks later; and weekly hand-weeding. Compared to unweeded containers, all six treatments reduced weed growth substantially, accompanied by increased but varied top dry weight response among species. In a related investigation, yew (Taxus × media 'Densiformis'), viburnum (Viburnum dentatum), and spirea (Spiraea × bumalda ' Froebellii') were container-grown for two years with eight treatments: Tex-R Geodisc, Biodisc, Corrudisc, ITML Weed Guard, and Mori Guard weed discs; Mori Guard weed sleeve; and pine sawdust and paper mill sludge mulches. Minimal and/or sporadic weed growth caused by near-drought conditions in year 1 and dense plant canopies in year 2, resulted in no difference in plant growth due to frequency (weekly, mid-season, end-of-season) of weed removal. There was no effect of the weed disc or weed sleeve treatments on plant growth, although the paper mill mulch caused Mn-deficiency related foliage chlorosis and reduced growth of yew.

CSHS Poster 1.6 Compost Leachate for Irrigation of Nursery Trees
Marek K. Jarecki* ¹, Calvin Chong² and R.Paul Voroney¹,
¹ Deptartment of Land Resources Science, University of Guelph, Guelph N1G 4Z6, Canada ² Deptartment of Plant Agriculture-Vineland, Vineland Stn., ON L0R 2E0, Canada Email: mjarecki@lrs.uoguelph.ca

Leachate from composting operations may contain organic and mineral components in concentrations that exceed water quality standards, and may serve as a supplementary source of plant nutrients. A field experiment was established in 1997 to evaluate the use of compost leachate collected in a pond at a composting operation for irrigating trees [silver maple (Acer saccharinum), green ash (Fraxinus pennsylvanica lanceolata), black locust (Robinia pseudoacacia), a poplar hybrid (Populus angulata x nigra var. plantierensis) and Carolina poplar (Populus x canadensis)]. The plants received three levels of irrigation (none, and 70% and 100% of the average long- term monthly rainfall during the growing season) and two levels of N+P fertilizer (100 kg N + 44 kg P per ha; and 200 kg N + 88 kg P per ha). During 1998 and 1999, the leachate significantly increased growth of the plants. In 1998 the higher NP resulted in larger trunk diameters of all tree taxa than lower NP, but in 1999 (after two seasons) the higher NP was better only for hybrid poplar and green ash. In 1998, leaf chlorophyll content also increased significantly in trees receiving the higher level of fertilization, and for hybrid poplar and silver maple was significantly correlated with foliar N content (r = +0.87 and + 0.91, respectively). The leachate increased leaf chlorophyll content also in black locust and hybrid poplar and foliar Na content in all taxa. In contrast, foliar N, P, K and Mg contents varied depending on the treatment, the year, and the plant taxa.

Keywords: compost leachate, irrigation, ornamental trees

CSHS Poster 1.7 20^th Century Trends in Quebec's Apple Industry. David Wees*
Macdonald Campus of McGill University, 21,111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec, H9X 3V9
Email: wees@macdonald.mcgill.ca

During the twentieth century, Quebec's apple production sector evolved from a collection of numerous small orchards scattered throughout the province to a large-scale industry dominated by a few regions and a half-dozen cultivars grown on dwarfing and semi-dwarfing rootstocks. The goals of this study were to identify some of the long term changes - and their causes - in apple production in Quebec using statistical data. Prior to 1950, Quebec produced 10,000 to 20,000 t of apples annually, making up about 5% of Canadian production. Following severe winter kill in 1933-34, many trees were planted in the 1930's and early 1940's leading to important increases in production during the 1950s; from the early 1960's through the late 1970's production averaged 100,000 t (5 million bushels) and accounted for 25% of the Canadian crop. After the severe winter of 1980-81, production dropped to 45,000 t; following extensive re-planting in 1981-1985, it increased to again reach 100,000 t in the 1990's, making up 17-18% of Canadian production. Until the 1980's, vigorous rootstocks were used almost exclusively; by the 1990's 35% of trees were dwarf and 44% were semi-dwarf. Before the 1930`s, 'Fameuse' and 'Wealthy' were very popular cultivars; 'McIntosh' became the cultivar of choice after the severe winter of 1933-34. In the 1960's and 1970's 75% of the crop was 'McIntosh'; that proportion decreased to 68% in the 1980's and 62% in the 1990's; 'Cortland', 'Empire', 'Spartan' and 'Paulared' have made up the difference. Before the 1970's less than 20% of the crop was processed; that proportion increased to ~50% in the late 1980's then declined to 35% in the 1990's. In the 1960`s there were over 2300 mainly small-scale orchards scattered on 10,000 ha of land throughout the St-Lawrence Valley and the southern part of Quebec; in the 1990's there were less than 1000 growers on 8,000 ha concentrated in three main areas: the Richelieu Valley (Rouville-Missisquoi), the Huntingdon-Hemmingford area along the border with New York State and the north shore of the Lake of Two Mountains (Oka - St-Joseph).

CSHS Poster 1.9 Broccoli Cultivars and Quality Ratings at Various In-row Spacings. A. W. McKeown *, C. J. Bakker. University of Guelph, Department of Plant Agriculture, Simcoe Campus, Simcoe, ON N3Y 4N5 Email: amckeown@uoguelph.ca

Wide in row spacings of 30 - 45 cm are recommended for broccoli in Ontario due in part to the risk of head rot. Finding cultivars better adapted to higher populations would increase yield potential. Over a three year period a number of cultivars were evaluated at in-row spacings ranging from 15 to 45 cm with 0.75 m between rows. Plots were replicated four times and arranged in a split-plot design with in-row spacings as main plots. Yields were determined and reasons for unmarketability rated on a 1 (undesirable) to 5 (desirable) scale. Yields were analysed by ANOVA, and Principal Components Analysis (PCA) used to determine which of the quality factors was related to cultivar, environment or spacings. Yields varied with the year, in part due to above normal temperatures in 1998, however there were several cultivars that were better at high populations. Misshapen heads were a primary reason for cull out. PCA indicated that 5 eigenvectors explained 78% of the variation. The first principal component explained 25% of the variation and appears to be related to quality. The relationships from the PCA will be discussed with regard to yield and quality. There are several cultivars that appear to tolerate higher populations than recommended while other clearly cannot. There is an opportunity improve broccoli production practices through higher plant populations with adapted cultivars.

CSHS Poster 1.10 Canada and Ghana: New Horticultural Partners D. D. Ceplis, P.Ag.*¹, E. N. Estabrooks, P.Ag.², and M. K. Pritchard, P.Ag ³¹ Information Technologies Division, Assiniboine Community College, Brandon, MB R7A 2A9 ² Evans & Associates Agricultural Consulting, 207 Shaw Lane, New Maryland, NB E3C 1J2 ³ School of Agriculture, University of Manitoba, Winnipeg, MB R3T 2N2 Email: Ceplis@assiniboinec.mb.ca In January 2001, an international project management team of the Canadian Society of Horticultural Science (CSHS) met with the Ghana Institute for Horticulturists (GhIH) in Ghana, West Africa to discuss the possibilities of the two scientific societies partnering for the purposes of

1. institutional strengthening in both Ghana and Canada and

2. increasing vegetable production during the dry season at rehabilitated dam sites in northern Ghana (known as the Upper West Region).

CSHS Poster 1.11 Is Pruning Weight an Accurate Expression of Vine Size? Justine E. Vanden Heuvel*¹, K.Helen Fisher ², and J.Alan Sullivan^{1 1} Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada N1G 2W1 ² Department of Plant Agriculture, University of Guelph, Vineland Stn., ON, Canada LOR 2EO Email: jvandenh@uoguelph.ca

The use of pruning weight as an expression of vine size is a common exercise in grapevine research, regardless of canopy management practices. The objective of this research was to investigate whether the relationship of pruning weight to other vegetative parameters was affected by canopy management. The correlation between several vegetative parameters and pruning weight of field-grown grapevines (cvs. Chardonnay/5BB and Cabernet Franc/5BB) on six trellising systems was investigated in 1999 in the Niagara region of Ontario. Trellising systems were classified into two groups: lower density canopy growth (Leaf layer number (LLN<2.0)) and higher density canopy growth (LLN>2.3) at harvest. Correlations of vegetative parameters and pruning weight on a per vine basis were significantly affected by canopy density. Pruning weight of low density canopies was not significantly correlated to any other vegetative parameters, while pruning weight in higher density canopies was significantly correlated to leaf number (r=0.51, p=0.0154), total leaf dry weight (r=0.67, p=0.0007), leaf area (r=0.55, p=0.0083), cane number (r=0.54, p=0.0082), and mean cane diameter (r=0.63, p=0.0013). In canopies where summer pruning did not occur, pruning weight had a stronger relationship to other vegetative parameters, such as leaf dry weight per vine (r=0.85, p=0.0329), leaf size (r=0.87, p=0.0244), and leaf area per vine (r=0.91, p=0.0131), indicating that the accuracy of using pruning weight as an expression of vine size may be dependant on canopy management techniques.

Keywords: Vitis vinifera L., pruning, trellising, vine size

CSHS Poster 1.12 To study current year and following year effects of chemical thinning on Gravenstien appleC. G. Embree* and D. S. Nichols

Achieving good fruit size and quality with annual cropping of apple cultivars is an important challenge in apple production worldwide. Gravenstien is a long standing example of a biennial apple cultivar. This study assessed current and subsequent cropping year effects for various exogenous plant growth regulators (PGRs) and Sevin^® XLR on biennial cropping of Gravenstein apple [Malus×domestica (L.) Borkh.] in a semidwarf orchard. The two PGRs (Accel^® and Fruitone^® N) were assessed with and without Sevin^® XLR, and two others (Promalin^® and Ethrel^®) were assessed without Sevin^® XLR. Fruitone^® N and Promalin^® were applied at petal fall. Sevin^® XLR alone and incombination with Accel^® and Fruitone^® N as well as Accel^® alone were applied at fruitlet diameter of 8.5 mm. Ethephon was applied at the 15 mm fruitlet stage. First year results show Accel^®, Sevin^® XLR + Accel^® and Sevin^® XLR + FruitoneN^® treatments all had larger crop-load values than Control. Sevin^® XLR + FruitoneN^® had the largest fruit size although not significant. The Ethrel^® treatment reduced crop-load below a commercial crop level. For the year-following response only the Accel^® treated trees had a significantly larger crop-load than control. Trees treated with Promalin^® had significantly lower blossom density, less crop-load and larger fruit size than other treatments tested. Ethrel^® and Accel^® increased the number of blossoms per cm². This report highlights the positive affect of Accel^® on minimizing biennial cropping of Gravenstien apple. The finding of the negative response of Promalin^® on biennial cropping are of interest. The interaction effect of PGR combinations with Sevin^® XLR are also discussed.

CSHS Poster 1.13 Physiological Responses of Carrot Seedlings Exposed to Drought Treasa Caldwell¹, R.Lada¹, and D.Hooper^{2 1} Department of Plant and Animal Sciences, Nova Scotia Agricultural College, Truro, Nova Scotia, B2N 5B1 ² Department of Chemistry, Atlantic NMR Faculty, Dalhousie University, Halifax, Nova Scotia

The study of drought tolerance has become a focus in agricultural research as a result of severe crop losses felt by farmers within the region, crippling the economy. Carrot crops, that occupy the second largest horticultural acreage in Nova Scotia, also experienced severe drought consecutively over three seasons from 1997 to 1999. Carrots are primarily grown under rainfed conditions, making drought a major environmental threat to carrot production. Identifying the physiological mechanisms and adjustments in carrots under drought as well as the threshold water potential at which physiological dysfunction begins to occur, would provide an understanding and assist in developing acclimation and/or adaptation strategies to protect this crop in the event of unexpected drought(s).

Three week old carrot (Daucus carota L var. Sativus) seedlings of variety Oranza, were exposed to various drought regimes by withholding water for 10 days in a controlled environment growth chamber. Growth and physiological responses were monitored. Decline in external soil water potential (_ext) resulted in a concomitant decline in xylem pressure potential( _x). Thresholds of approximately -0.36 MPa _ext as well as _x above -0.6MPa was determined. These thresholds were evident in all physiological and metabolic responses recorded. At the threshold water potential photosynthesis, stomatal conductance, leaf transpiration, water use efficiency were all declined with an increase in membrane damage as observed by an increase in membrane leakage. Stomata closed quickly even before the plants reached a threshold water potential, which lowered leaf transpiration. A leaf area adjustment as well as a sensitivity of elongation growth as oppose to expansion was implied through observations of plant growth over the various drought periods. These results indicate that carrot seedlings may use a water conservation strategy to tolerate drought and a critical threshold xylem pressure potential for the initiation of physiological dysfunction was at or above -0.6MPa.

CSHS Poster 1.14 Thermogenic compounds promote carrot seed germination at a low temperature.
Lada R. Rajasekaran*, Azure Stiles, Claude Caldwell

The possibility of hastening carrot seed germination at low temperature using thermogenic compounds such as salicylates (SAs) was explored. Seeds were incubated at various temperatures viz., 25, 20, 15, 10, 5 and 2C. Salicylates such as 2, 6-dihydroxybenzoic acid (DHBA), acetylsalicylic acid (ASA), and salicylic acid (SA) were supplied at 0, 1, 10, 100 or 1000 mg.L^-1 continually to the seeds incubated at 25C or 5C until germination. Data on germination percentage was collected and vigor value was calculated. Incubating seeds at various low temperature regimes significantly and proportionally reduced germination percentage and vigor value. Temperature optimum for obtaining high germination rate and vigor value was 25C. Critical threshold temperature for germination (GT₅₀) was 5C. Salicylate seed treatment hastened germination at 5C. DHBA 1, ASA 100, SA 1 mg.L^-1 were all effective in hastening germination at 5C. Among the salicylates, ASA 100 mg.L^-1 was the most effective in advancing germination at 5C. Salicylates at the highest concentration of 1000 mg.L^-1 inhibited germination significantly both at 25 and 5C. Salicylate-hastened germination at low temperature may perhaps be due to their thermogenic activity, increasing activation energy for germination or by triggering alternate oxidase genes.

CSHS Poster 1.15 The Role(s) of Plant Growth Regulators in Triggering and Enhancing Bulking of Dicer Carrots. C.E. Neuteboom^{* 1}, R. Lada¹, C. Caldwell¹, L. Eaton², P. Havard^{3 1}Department of Plant and Animal Sciences, Nova Scotia Agricultural College, PO Box 550, Truro, Nova Scotia, Canada B2N 5E3 ² Department of Environmental Sciences, Nova Scotia Agricultural College, PO Box 550, Truro, Nova Scotia, Canada B2N 5E3 ³Department of Engineering, Nova Scotia Agricultural College, PO Box 550, Truro, Nova Scotia, Canada B2N 5E3 Email:ceneuteboom@nsac.ns.ca

One and half to two inch diameter roots are generally preferred for dicing and grades exceeding 2" are also accepted. Nearly, 30-50% (depending on the variety) of the roots do not reach the preferred grade of above 11/2". Larger the root size greater the yield and profitability to a producer. Achieving root grades exceeding >2" in dicer carrots can be challenging especially in areas with cool springs, low average irradiance and cool, cloudy autumns. Since, root bulking and maturity is a physiological consequence associated with the histological developments of the storage roots including secondary cambial sheath formation and subsequent cell division, hastening histological developments by accelerating cambial sheath formation, cell division and increasing root sink capacity may trigger and enhance root bulking. These processes are regulated by phytohormones. Ethylene has been implicated in triggering cambial activity, membrane permeability and increasing sink activity in several species, implying that it may have a role in triggering bulking of storage roots in carrots.

In field trials, ethephon^TM (3-chlorophosphonic acid), an ethylene releasing compound was applied to dicer carrots (Daucus carota var. sativus) in two field locations (Great Village and Avonport) in Nova Scotia. Ethephon was applied at concentrations of 1, 10, 100, 1000 ppm at 2 weeks post-emergence, 2 and 4 weeks post-emergence or 2, 4 and 8 weeks post-emergence. Each treatment was replicated three times. The study adopted a CRD. Root girth, fresh root and shoot weight were monitored at each application. One meter samples were harvested and analysed for yield, root density, root girth and grade distribution. Leaf Area Indices were taken at 10 weeks, post-emergence using LI 2000.

Fields differed in responses throughout the season. Significant differences in root girth and weight as well as shoot weight were observed during the early phase of growth, with significant increases in root girth when ethrel was applied at 10 ppm concentration 4 weeks post-emergence in Great Village. At Avonport however, significant difference in root girths was observed at harvest in plants that received 1 ppm ethrel, applied at 2 weeks post-emergence. Ethrel at 10 ppm applied at 2, 4 and 8 weeks enhanced root bulking in Great village. There was however no significant differences in yield or recovery which may perhaps be due to low PAR as a result of several cloudy days throughout the season.

CSHS Poster 1.16 Characterization of endophytic plant growth promoting (PGP) bacteria, their location, population density, and biodiversity in processing carrots (Daucus carota L. var. sativus) Monique A. Surette* ¹, Antony V. Sturz², Rajasekaran Lada¹, Jerzy Nowak^{1,3 1} Department of Plant and Animal Sciences, Cox Institute, Nova Scotia Agricultural College, PO Box 550, Truro, NS, Canada, B2N 5E3, ² Prince Edward Island Department of Agriculture and Forestry, PO Box 1600, Charlottetown, PEI, Canada, C1A 7N3, ³ Virginia Polytechnic Institute and State University, 301 Saunders Hall, Blacksburg, VA, USA, 24061 Email: Masurette@nsac.ns.ca

A survey of endophytic bacteria colonizing processing carrots (Daucus carota L. var. sativus) was performed with 2 carrot cultivars (Carochoice, Red Core Chantenay) grown at 2 field locations (Canning, Great Village) in Nova Scotia. Most endophytic CFU were recovered from the carrot crown tissues (96%) compared to the periderm and metaxylem tissues irrespective of the cultivar and field location. The greatest population densities of endophytic bacteria were recovered from the crowns of cv. Red Core Chantenay carrot (Great Village) (52% of all of CFU recovered). Of 360 isolates examined, 28 bacterial genera were identified, of which Pseudomonas, Staphylococcus, and Agrobacterium were the most common (31%, 7% and 7% respectively). A bioassay using selected strains of bacteria was performed on 4 week-old carrot (cv. Bergen) and potato (Solanum tuberosum cv. Atlantic) plantlets. In carrots, 83% of the bacterial strains tested were found to be plant growth promoting,10% plant growth neutral and 7% plant growth inhibiting. In contrast the potato bioassay revealed a differential response with 38% neutral, 33% promoting and 29% inhibiting growth. In general, carrot endophytes did not show any carrot cultivar specificity but were less effective growth promoters of potatoes.

CSHS Poster 1.17 Tree Covers Provide Superior Protection Against Rain-Induced Fruit Cracking in Comparison with Intermittent Calcium Chloride Misting during Rain Events John A. Cline*¹ ,Ken Sligerland ², and Hugh Fraser ²

Rain-induced cracking of sweet cherries (Prunus avium) is a serious problem which results in large crop losses at harvest in many cherry producing areas of the world. The most widely held view is that cracking is caused by the direct absorption of rain water through the fruit skin. Several calcium compounds including calcium chloride (CaCl₂) have been evaluated in the past, all with inconsistent results. A method which intermittently applies a 0.5-0.1 % CaCl₂ solution to trees during a rain event has been reported to significantly reduce rain-induced fruit cracking (Flore et al, 1997). In addition, rain exclusion tree covers have been reported to significantly reduced cracking in wet years. An experiment (RCB design) with four replications was established in 1998 to measure the reduction in fruit cracking from 'Vandalay' /Mazzard trees (planted in 1989) treated with: a) an intermittent 0.5% (w/v) CaCl₂ solution applied with an overhead micro-sprinkler during each rainfall event within three weeks of harvest; b) covered with polyethylene plastic, and; c) left untreated. In one out of three years, fruit cracking from covered trees was significantly reduced by 22% (P=0.001) in comparison with untreated trees. In contrast, CaCl₂ did not significantly reduce fruit cracking, even though numerically cracking was reduced by 11% in comparison with untreated control trees.. Fruits from CaCl₂ treated trees were significantly smaller and had significantly lower percent soluble solids in one of the three years (P=0.01). These data indicate that in a three year test which differed in rainfall, tree covers provided that greatest protection against rain-induced fruit cracking and that misting with CaCl₂ inadequately controlled fruit cracking and indeed had a detrimental effect on fruit size, soluble solids, and tree health.

Key words: rain-induced fruit cracking, Prunus avium

Biotechnology, Breeding and Genetics

Abstracts for Oral Session 2

Poster Session 11:10-12:00

Peter Clark Hall, University Centre

CSHS Oral 2.1 The Quebec Strawberry and Apple Breeding Programs: An Overview

Shahrokh Khanizadeh*, Yvon Groleau, Johanne Cousineau¹, Jennifer DeEll, Martine Deschenes and Audrey Levasseur

Agriculture and Agri-Food Canada, Research Station, 430 Blvd. Gouin, St-Jean-sur-Richelieu, QC, J3B 3E6, Canada Email:khanizadehs@EM.AGR.CA

The fruit breeding and physiology work carried out by the Quebec strawberry and apple breeding programs located at the Agriculture and Agri-Food Canada (AAFC) Research Centre in St-Jean-sur-Richelieu (Quebec) is based on regional mandates and priorities. The Quebec apple breeding program was initiated in 1970 with the transfer of genetic material from Dr. Lloyd Spangelo of the Ottawa Research Station to the AAFC sub-station located in Frelighsburg (Quebec). Since 1970, numerous cultivars have been released by the Quebec breeding program including 'Blair' (1973), 'Richelieu' (1990), 'Rouville' (1991), 'Primevère' (1995) and 'Belmac' (1995). The present program is divided into five sections (rootstocks, ornamentals, scab resistant selections, non-scab resistant selections and processing apples) based on the evaluation of existing germplasm. Many of our semi-advanced apple and rootstock selections are presently being tested for their hardiness and tolerance to pests and diseases through partnership programs sponsored by the private sector and growers associations. We also have several selections (10280, 79-09, R124A04, R125A44, R130A09, 74-50-13, 77-13-11, A14R3A108, A16R5A15, A23R7A60, A33R5A67, A36R7A87, A38R6A74, FAR006A013, FAR026A042, FAR095A007, O-5410, O-654, O-662) entered into advanced trials. Specific techniques have been developed or adapted to accelerate the screening process including greenhouse testing for diseases, chlorophyll fluorescence for the assessment of shelf life, the use of controlled atmosphere chambers to enhance shelf life and advanced sensory evaluation techniques for processed apples (especially cider). The Quebec strawberry breeding program has the mandate to develop hardy, disease and pest resistant strawberry cultivars adapted to the Quebec climate. This program has released several cultivars with diverse agronomic characteristics and in several cases with resistance to fungal diseases such as leaf spot, powdery mildew and red stele (Chambly, Oka, Joliette, Yamaska, L'Acadie and Saint-Pierre). The present strawberry breeding program is divided into five sections (June-bearing, day-neutral, ornamental, processing and extended shelf life) based on regional needs and mandates. Several partnership programs have been established to meet these objectives. 'L'Authentique Orléans' is the first June-bearing cultivar developed through joint collaboration between AAFC and its private partner Les Fraises de l'Ile d'Orléans Inc. This cultivar was released in 2000 for its good fruit quality, long shelf life and high antioxidant content. A separate partnership program with Lareault Inc. and Phytoclone has resulted in the release of 'Rosalyne', a day-neutral, hardy, red flowering cultivar developed for home gardeners. This new cultivar produces large, showy red blooms and aromatic fruit all summer long. The Quebec strawberry breeding program uses several techniques and methods to accelerate the breeding process including chlorophyll fluorescence for the detection of frost resistance in blooms, the analysis of antioxidant levels and the relationship between these levels and pre/post-harvest fruit rots and disease resistance, and the use of DNA fingerprinting, phylogeny and RAPD marker analyses vs. a similarity index to assess parents and progeny. Additional information on both breeding programs can be found at www.pgris.com.

Biotechnology, Breeding and Genetics

Abstracts for Poster Session 2

Poster Session 11:10-12:00

Peter Clark Hall, University Centre

CSHS Poster 2.1 Application of in Vitro Techniques Combined with Classical Methods in Small Fruit Development Program for Cool Climates.

S.C. Debnath*, Atlantic Cool Climate Crop Research Centre, Agriculture and Agri-Food Canada, P.O. Box 39088, St. John's, NF A1E 5Y7, Canada.

Email: debnaths@em.agr.ca

Lingonberry (V. vitis-idaea L.), cranberry (V. macrocarpon Ait.), lowbush blueberry (V. angustifolium Ait.) and bakeapple (Rubus chamaemorus L.) are four small fruit crops economically important to Atlantic Canada. The collection, preservation and sale of wild grown berries have played an important part of the economy for rural areas of this area. Commercial exploitation of these tasteful fruits has been difficult because the productivity is often low in natural stands. Improvement of lingonberry, cranberry, blueberry and bakeapple can be done by selecting superior clones from natural populations followed by multiplication through micropropagation for further evaluation. Alternately, crosses can be carried out among promising genotypes to combine desired traits into the new combination. The aim of the Small Fruit Development Program of Atlantic Cool Climate Crop Research Centre (ACCCRC) is to use the excellent tools of biotechnology to speed up the traditional improvement process by multiplying rapidly the selected native clones and the hybrids obtained by crossing different genotypes or by selecting superior genotypes under in vitro condition. Summarized here are the advances in using some of the tools of biotechnology and the current status of the program for small fruit improvement in the ACCCRC of Agriculture and Agri-Food Canada in St. John's, Newfoundland.

CSHS Poster 2.2 The Role of Duplicate Alcohol Dehydrognase Genes in a Higher Plant - Petunia Hybrida.
Frey Garabagi* & Judy Strommer. Dept. of Molecular Biology and Genetics. University of Guelph, Guelph, ON N1G 2W1

The alcohol dehydrogenase gene family in Petunia hybrida consists of two members, adh1 and adh2. Data from ADH activity gels and two lines of transgenic petunia plants using a GFP reporter driven by one or the other promoter show that adh1 and adh2 have overlapping developmental expression patterns. Developmentally, expression of adh1 is specific to pollen and adh2 to nectaries, petals and filaments. Evidence of both promoter functions is in mature seeds, developing anthers, stigmas, styles and ovaries. While overlapping expression patterns of the two adh genes hints to some redundancy in expression, tissue specific expression patterns of the adh genes suggests presence of specific roles for the family members.

CSHS Poster 2.3 Galarina and Reinette Russet: Two New Scab-Resistant Apple Cultivars originating from INRA, France

Shahrokh Khanizadeh¹, François Laurens², Yves Lespinasse², Yvon Groleau¹, Johanne Cousineau¹, Jennifer DeEll³

2 INRA - C.R. d'ANGERS, Unité d'Amélioration des Espèces Fruitières et Ornementales, B.P. 57 - 49071 Beaucouze Cedex - France

O.M.A.F.R.A., 4890 Victoria Ave N., Box 8000, Vineland Station, ON, L0R 2E0

Email: khanizadehs@em.agr.ca

Several apple selections originating from European breeding programs have been evaluated during the last 10 years at our station in Frelighsburg (Quebec). Two selections from the breeding program at INRA - C.R. d'ANGERS (Unité d'Amélioration des Espèces Fruitières et Ornementales, France) look promising for commercial trials in Quebec. They are being released under the name 'Galarina' and 'Reinette Russet'. 'Galarina' ('Florina' x 'Gala') is a 'Gala' type apple with improved resistance to apple scab and a long shelf life. The flesh is very firm, juicy and aromatic with a low level of discoloration after cutting. 'Reinette Russet' (mutation of 'Reine des Reinettes')is very similar to 'Golden Russet' but it produces larger fruit and is partially resistant to apple scab. The skin is covered with a fine russet and the flesh is very sweet, firm and moderately juicy. This cultivar is good for specialty fresh markets because of its sweetness and it is also being evaluated for cider production.

Keywords: Malus domestica, Venturia inaequalis, apple breeding, cider production, shelf life

CSHS Poster 2.4 New Hardy Apple Scab Resistant Selections for Cider and Juice Production

S. Khanizadeh*, Y. Groleau, I. Ali, D. Guarino and R. Dumois, Agriculture and Agri-Food Canada, Research Station, 430 Blvd. Gouin, St-Jean-sur-Richelieu, QC, J3B 3E6, Canada; Department of Food Sciencesand Agricultural Chemistry, McGill University, QC H9X 3V9 and Verger de Minot

C. P. 658, Hemmingford, J0L 1H0

Email: khanizadehs@em.agr.ca

Five hardy scab resistant selections (12166, 10625, 0-654, 13323, 14199) were put in replicated trials along with four standard cultivars (Yarlington Mill, Golden Russet, McIntosh Summerland, Makamik) to evaluate their potational for cider production. A taste panel consisting of 6 certified commission judges evaluated the cider samples. The cider was evaluated for aroma and taste with an emphasis on flavour and taste-related components e.g. fruit intensity, appeal, acid and tannin levels. Of all the genotypes tested, ciders made from 'Yarlington Mill', '12166', and '10625' were ranked the best followed by 'Golden Russet and 'McIntosh Summerland'.

Keywords: Malus domestica, scab resistance, apple cider

CSHS Poster 2.5 New hardy rootstocks from the AAFC Quebec apple breeding program

Shahrokh Khanizadeh* and Yvon Groleau, Agriculture and Agri-Food Canada, Research Station, 430 Blvd. Gouin, St-Jean-sur-Richelieu, QC, J3B 3E6, Canada

mail: khanizadehs@em.agr.ca

Thirty hardy wooly aphid disease resistant rootstocks were selected from a 800 rootstocks seedling obtained from Malus robusta R-5 x M.26, Malus robusta R-5 x Budagovsky 57490 and an open-pollinated Ottawa 3. A trial was conducted in Frelishburg, Quebec, a sub-station of Agriculture and Agri-Food Canada to evaluate these selections using 'Spartan' as scion. Seven of these rootstocks were found to be very hardy, disease and pest resistant and efficient under Quebec environmental conditions, and are being tested further.

Keywords: Malus domestica, scab resistance, columnar, fruit breeding Juice and Cider

CSHS Poster 2.6 Breeding Winter-Hardy Strawberries for Northern Ontario

B. R. Hughes*¹ and A. Dale ²

¹ New Liskeard Agricultural Research Station, University of Guelph, New Liskeard

Department of Plant Agriculture, University of Guelph, Simcoe

Email: bhughes@onlink.net

The New Liskeard Agricultural Research Station is located 500 km north of Toronto in Canadian hardiness zone 3a. The area has an average of 1500 growing degree days (>5C) and between 100 and 120 frost-free days. At this location many strawberry cultivars yield inconsistently, consequently a breeding program was started in 1993 to breed winter-hardy strawberries adapted to northern Ontario. A series of nine crosses were made between three ultra-hardy cultivars, 'Beaver Belle', 'Beaver Early' and 'Beaver Sweet', and three large-fruited, firm Simcoe selections, 137A84, 319A92 and V7737-2.

One advanced selection, 16NL11, is seven to ten days later than 'Veestar' and has outyielded 'Cavendish' in two out of three years. The berries are similar in size and a lighter red than 'Cavendish'. 16NL11 is a promising selection for northern climates exhibiting winter hardiness, high yields and good berry size. It is currently in trials at five grower sites across northern Ontario. These trials are located in zones 3a through 4b close to the cities of North Bay, Sudbury, Sault Ste. Marie and Thunder Bay.

Keywords: Fragaria x ananassa, fruit breeding

CSHS Poster 2.7 The Proportion of Seedlings from Unreduced Gametes in Rubus

J. Alan Sullivan*, Jan Brazolot and Harry Jan Swartz; Department of Plant Agriculture, University of Guelph, Guelph, Ont., Canada, N1G 2W1

E-mail: asulliva@uoguelph.ca

Flow cytometry was used to determine the ploidy of 801 seedlings from 11 tetraploid x diploid Rubus crosses. The percentage tetraploid seedlings, apparently from fertilization with unreduced pollen, averaged 5.7% but ranged from 0% to 24% for different parental combinations. The proportion of tetraploid seedlings was not related to pollen source, female parent or the percentage of the seedling population which survived from embryo rescue in vitro to the time of assay at 3 months post germination. Tetraploid seedling vigor was not different than triploid seedling vigor. One percent of the seedlings were pentaploid, apparently from unreduced eggs and 0.2% were hexaploids presumably from the union of two unreduced gametes. The proportion of large pollen grains, determined by flow cytometry, ranged from 0.2% to 2.8% and did not relate by progeny to proportion of tetraploid seedlings.

Keywords: raspberry, ploidy, flow cytometry

Abstracts for Poster Session 3

Medicinal Plants and Novel Crops

Poster Session 3:15-4:00

Peter Clark Hall, University Centre

CSHS Poster 3.1 Effect of Physical Property of Coriander Fruit on Composition and Yield of Essential Oil

Manjula Bandara* and Elizabeth Russell, Alberta Agriculture, Food and Rural Development, Crop Diversification Centre-South, S.S. # 4, Brooks, Alberta, T1R 1E6, Canada

Email: manjula.bandara@gov.ab.ca

Coriander is the main spice crop grown in the Canadian Prairies. The essential oil content of the fruit varies between 0.03 to 2.5% and the main component, linalool, is used as the quality standard for coriander essential oil. One of the main factors influencing the essential oil yield and quality of coriander is physical property (mean fruit weight, split or crushed fruit %) of the fruit. This study examined the effect of physical property of coriander fruit on the composition and total yield of essential oil. Treatments included were whole, split and ground fruits with two size categories and were replicated twice.

Results indicated that physical property of the fruit and extraction time had a significant impact on total yield and composition of the essential oil. Small fruit (9-11g/1000 fruits) contained over 1.6-fold higher essential oil yield compared to that of larger-fruited treatments (15-17g/1000 fruits). The essential oil extracted from whole fruit had a significantly higher linalool content compared to other treatments. However, the ground fruit treatment consistently produced significantly higher oil yield than whole and split treatments and consequently the ground treatment produced the highest linalool yield. Grinding of fruit prior to hydro-distillation enhanced the oil recovery rate and therefore reduced the oil extraction period by at least 1.5 hours. In summary, results indicate that grinding of fruit prior to hydro-distillation improves essential oil recovery rate, total essential yield and total linalool yields of both small-and large-fruited coriander, while splitting of fruit improves total oil yield, particularly in small-fruited coriander.

Key words: Coriandrum sativum L.; hydro-distillation; mean fruit weight; oil recovery rate.

CSHS Poster 3.2 Tree nuts: an Example of a Diversification Crop.

Diversification of crop species grown in Ontario to create new market opportunities for growers is an ongoing process. Hybrid sweet chestnut (Casteanea mollissima X C. denata, C. sativa, C. crenata) and heartnuts (Juglans ailantifoloia var cordiformis), are grown in varying amounts by nut growers in the southern part of the Province. One problem common to most diversification crops is the lack of scientific and applied knowledge under Ontario conditions. There have been no formal comparisons of heartnut cultivars under our climate and high rate of tree mortality has occurred with grafted hybrid chestnuts on sandy soils. The intent of this work was to compare heartnut cultivars and three chestnut establishment treatments: fumigation, mulching and fertility levels. Land was prepared in the fall of 1994 and trees were planted in the spring of 1995. Heartnut cultivars were CW3, Imshu and Fodermaier grafted on black walnut root stock. Grafted Layeroka Chinese hybrid chestnuts were planted with +/- fall Vorlex fumigation, 450 or 900 g/tree of 10-10-10 fertilizer and +/- sawdust mulch at 73 l/tree for 2 years. Tree diameters were recorded each spring commencing in 1996 to estimate vigour. Harvest commenced in 1999. CW3 is the least vigorous of the heartnut cultivars but had the highest yield in 1998, 2000 suggesting an alternate bearing habit. These trees are still young and the pattern may evolve with time. Imshu is has smaller kernels but is easier to split and separate from the shell than CW3. Mulching in the planting and second year increased tree vigour of chestnuts until 2000. Fertility or fumigation had no effect on trunk diameter. Layeroka continues to flower and set fruit until killing frosts. Mulching increased the yield of jumbo nuts (> 32 mm) in 1998, 1999 and number one grade (> 22 mm, < 32 mm) in all three years. Over the years since planting, tree mortality has been approximately 30% but no effects of treatment have been observed. Tree nuts are long term crops and more time is required to fully evaluate the trials. However, initial indications are that: some returns can be obtained 4 years after planting, pruning systems need to be developed for heartnuts in particular, mulching each year appears necessary and better chestnut cultivars are required.

Key words: Diversifaction crops, heartnuts, chestnuts, yield.

CSHS Poster 3.3 Use of Strains of Trichoderma in Controlling Diseases of North American Ginseng Caused by Cylindrocarpon destructans.

I. Caldwell, H.-Y. Ju, S.K. Asiedu*, S.C. Hong, and B. Gray. Nova Scotia Agricultural College, P.O. Box 150, Truro, N.S. B2N 5E3, Canada.
Email: sasiedu@nsac.ns.ca

Root diseases are a major limiting factor in the growth and quality of ginseng. One of the main root disease causing pathogens of ginseng is Cylindrocarpon destructans. This fungus causes seed rot, damping off of seedlings, and root rot in roots of three to four year old plants, but no effective control method is available. The aim of this study was to test effectiveness of the fungus Trichoderma against C. destructans. Several strains of Trichoderma were applied to agar medium containing the disease to test which strains resulted in antagonism. Four strains (A8, A32, A161, and A321) were identified as especially antagonistic. These four strains were applied to growing seedlings planted in soil containing Cylindrocarpon destructans in a greenhouse. Strains were applied individually or in combination and compared to Benomyl and Propiconazole. Individual strains had no significant effect but the combination of all isolates reduced incidence of seedling root rot, increased emergence of seedlings and increased overall plant growth. In vitro tests on suppression of C. destructans by the various combinations of the four strains of Trichoderma was

performed on agar. All combinations resulted in equal amounts of disease suppression except the combination of strains A8 and A161. Further studies are being conducted on potential field use of these Trichoderma strains. The application of a Trichoderma sp. bioagent to decrease

incidence of root rot and other diseases provides an environmentally friendly alternative to chemical methods and would be more attractive to consumers.

Key words: ginseng, disease, Trichoderma, Cylindrocarpon, biocontrol

CSHS Poster 3.4 Stratification and Priming May Improve Seed Germination of Purple Coneflower, Blue-Flag Iris and Evening Primrose.

David Wees*, Macdonald Campus of McGill University, 21,111 Lakeshore Road

Ste-Anne-de-Bellevue, Quebec, H9X 3V9 Email: wees@macdonald.mcgill.ca

Several North American native wildflowers have potential for medicinal and ornamental use but the seeds of some species have poor, slow or erratic germination. The goal of this project was to improve seed germination with stratification or priming (osmoconditioning); species tested were purple coneflower (Echinacea purpurea), narrow leaf purple coneflower (Echinacea angustifolia), Blue-Flag Iris (Iris versicolor) and Evening Primrose (Oenothera biennis). In 1997, stratification consisted of storing seeds at 4^o-5^oC in wet paper towels for 4 weeks; priming consisted of soaking seeds in an aerated 0.1 M solution of KNO₃ for 5 days. In 1999, stratification lasted 3 weeks; priming was with 0.1 M or 0.2 M aerated solutions of KNO₃ for 1 week. With Iris versicolor stratification, priming and the control treatment gave respectively 59%, 33% and 10% germination, 44 days after seeding (DAS) in 1997. With Echinacea purpurea stratification, priming and the control treatment gave respectively 82%, 69% and 44% germination 21 DAS. With Echinacea angustifolia, stratification priming and the control treatment gave respectively 22%, 24% and 12% germination 21 DAS. With Echinacea, primed seeds germinated fastest; with Iris versicolor stratified seeds germinated first. Germination of Oenothera biennis in 1999 was only slightly improved by stratification (71%) or priming (68% in O.1 M, 74% in 0.2 M) compared to raw seed (67%) 15 DAS; both priming and stratification reduced time to germinate. With Iris versicolor in 1999, stratification and priming gave 17% and 1% germination compared to 0% with raw seed 33 DAS. With Echinacea angustifolia stratification gave 9% germination, priming 4% (in 0.1 M) and 9% (in 0.2 M) germination and the control 3% germination 40 DAS.

Key words: Echinacea, Iris versicolor, Oenothera biennis, germination, stratification, priming

CSHS Poster 3.5 Influence of Planting Arrangements and Leaf Removal on Garlic Yields

John W. Zandstra*, Ridgetown College, University of Guelph, Ridgetown ON. N0P 2C0
Email: Jzandstr@ridgetownc.uoguelph.ca

Planting arrangements and leaf removal of garlic were evaluated for their influence on yield and bulb size. Row width is often dependant upon machinery available to the grower, and ranges from 20 to 70 cm in Ontario, while recommendations for in-row clove spacings are 7-12 cm. Leaf removal can occur if growers remove the scapes (flower stalk) of hardneck garlic mechanically in years when they have little market value. Yields of the hardneck strain "Music" were found to increase quadratically while bulb weights decreased linearly as row widths and in row clove spacings decreased from 65 and 15 cm respectively. Yields and bulb weights decreased linearly as increasing numbers of leaves were removed during early scape development; by removing only 1 leaf (approximately 11% of total leaf area) bulb size was reduced by 13% and yield was reduced by 17.5 %.