Location: Horticultural Crops ResearchTitle: Abscisic acid form, concentration, and application timing influence phenology and bud cold hardiness in Merlot grapevines Author
|Bowen, Pat - Agri Food - Canada|
|Mills, Lynn - Washington State University|
|Willwerth, Jim - Brock University|
|Bogdanoff, Carl - Agri Food - Canada|
|Keller, Markus - Washington State University|
Submitted to: Canadian Journal of Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/25/2015
Publication Date: 5/24/2016
Citation: Bowen, P., Shellie, K., Mills, L., Willwerth, J., Bogdanoff, C., Keller, M. 2016. Abscisic acid form, concentration, and application timing influence phenology and bud cold hardiness in Merlot grapevines. Canadian Journal of Plant Science. 96:347-359. doi: 10.1139/cjps-2015-0257.
Interpretive Summary: Sustainable production of the wine grape cultivar Merlot at northern latitudes is challenged by the occurrence of extreme cold weather events that injure dormant buds and other cold-senstive tissues. Increasing the bud cold hardiness of Merlot could enhance its resilience to cold injury and therefore its performance in northern growing regions. The plant hormone abscisic acid (ABA) is involved in the promotion of dormancy and cold acclimation in plants. Foliar application of ABA solutions have been found to increase cold hardiness in other crops and some ABA analogues have been found to be more effective than natural ABA. The objective of this study was to compare the effectiveness of naturally occurring and analogue forms of ABA on increasing the bud cold hardiness of ‘Merlot’ grapevines grown in northern production regions. The study was conducted over three consecutive years at field trial locations in the U.S. and in Canada. Bud cold hardiness was influenced by ABA formulation. Natural ABA tended to be most effective during autumn acclimation whereas the ABA analogue was most effective during spring deacclimation. Results from this study, in combination with historical weather data, can be used to guide selection of the most suitable ABA form for a given production region. The ABA analogue would be most appropriate for production regions prone to spring cold events whereas natural ABA would be more suitable for use in regions prone to autumn cold weather events.
Technical Abstract: The effects of abscisic acid (ABA) form, concentration and application timing on bud cold hardiness, phenology and fruiting performance on ‘Merlot’ grapevines (Vitis vinifera) were evaluated in a three year field trial with site locations in British Columbia Canada, Ontario Canada, Washington U.S. and Idaho U.S.. Solutions containing natural ABA (ABAN) and a purported long-lived ABA analogue (ABAA, Valent BioSciences VBC-30158) at differing concentrations were applied to the vine canopy at veraison or immediately following harvest. Postharvest foliar applications of ABAN at concentrations greater than or equal to 5000 ppm tended to advance leaf fall and increase autumn bud cold hardiness. Postharvest foliar applications of ABAA at 1000 ppm tended to delay budbreak the spring following application and increase spring bud cold hardiness. Fruit yield and basic composition were affected little by the ABA treatments. In production regions most prone to injurious, late spring cold events, ABAA would be more suitable than ABAN because ABAA enhanced hardiness in spring when injurious cold events are most likely. ABAN would be more suitable than ABAA in production regions most prone to injurious cold events in autumn because ABAN enhanced autumn acclimation.