Page 23 - CSHS 2022 Book of Abstracts - 2022-08-22 web version

CSHS 2022 Conference

(FO.7) Integration of Salicylic Acid into a Conventional Spray Programs of Apple
Michael S. McLaughlin 1,2* , Pervaiz A. Abbasi , Balakrishnan Prithiviraj , Shawkat Ali
2
1
1
1. AAFC, Kentville, NS; 2. Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie
University, Bible Hill, NS
________________
For decades, chemical fungicides have been the primary means of controlling fungal pathogens in apple orchards
typically involving 12-14 applications over the course of a growing season. However, some fungicides have come
under increasing scrutiny due to their negative impacts on environment, and on animal and human health, leading
to increased restrictions on their use. As fungicides are increasingly restricted, additional, eco-friendly disease
management tools are necessary. In this study, the plant defense elicitor, Salicylic Acid (SA), was integrated into a
conventional spray program for the control of fungal pathogens on ‘Honeycrisp’ apples, replacing 6 (2019 and 2020)
and 4 (2021) applications of fungicides in conventional spray programs, respectively. The experiment was
conducted in an experimental orchard at the Kentville Research and Development Centre as well as in commercial
orchards in Nova Scotia, New Brunswick, and Prince Edward Island. In the experimental orchard, no significant
differences in disease incidence were observed between traditional fungicide and the integrated program on foliage
throughout the growing season, nor on apple fruit at harvests or after a 3 month storage periods. Similar results
were observed in apple fruit harvested from the commercial orchards, with the exception of the New Brunswick
orchard, in which the integrated spray program performed better against black rot than the traditional spray
program (12.75% vs 16.75% respectively). This research underscores the potential of integrating SA into spray
programs to maintain disease control while reducing fungicide usage.

(FO.8) Quantitative proteomic investigation on storage quality of ‘Honeycrisp’ apples after pre-
harvest and postharvest treatment of 1-MCP
Jun Song , Yihui Gong , Jennifer DeEll , Melinda Vinqvist-Tymchuk , Leslie Campbell-Palmer ,
1
1*
3
2
1
Sherry Fillmore , Geoffrey Lum , and ZhaoQi Zhang
2
2
2
1. AAFC, Kentville, NS; 2. College of Horticulture, South China Agriculture University, Guangzhou, China; 3. Ontario
Ministry of Agriculture, Food and Rural Affairs, Simcoe, ON
________________
1-Methylcyclopropene (1-MCP), an ethylene action inhibitor, has been widely applied in the fruit industry to
maintain and extend the shelf life of fruit, especially apples. The traditional application of 1-MCP has been expanded
from being only a postharvest treatment to pre-harvest in a spray form. Despite awareness that treatments can
maintain fruit quality and reduce some physiological disorders, fundamental biochemical knowledge about 1-MCP
treatment on fruit quality is still needed. To reveal the protein changes in relation to fruit quality with respect to
pre- and postharvest 1-MCP treatment, we conducted a quantitative proteomic experiment employing stable isotope
labeling by peptide dimethylation on ‘Honeycrisp’ apples. Apples treated with 1-MCP pre-harvest, postharvest or a
combination of both treatments were evaluated after cold storage for 7 months. We found the significant changes in
fruit ethylene concentration, fruit quality indices and incidence of physiological disorders. WE also quantified
proteins changes and found proteins that were common in all treatments. Importantly, we identified proteins that
changed significantly in abundance in response to pre-harvest, postharvest and combining treatments of 1-MCP
respectively. We also report a small group of proteins that were only seen to response to pre-harvest 1-MCP
treatment. Combining the results from all treatments, proteomic changes reveal and confirm that ethylene
biosynthesis, stress resistance, antioxidant, redox system as well as phenylpropanoid metabolism have direct link to
the 1-MCP treatment. We discuss the potential metabolomics changes resulting from the various means of 1-MCP
treatment and the efficacy of pre-harvest 1-MCP treatment.

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