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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Publications at this Location » Publication #309368

Research Project: Sustainable Vineyard Production Systems

Location: Crops Pathology and Genetics Research

Title: Pruning for prevention and management of canker diseases

Author
item Baumgartner, Kendra
item Westover, Fritz - VINEYARD TEAM

Submitted to: Trade Journal Publication
Publication Type: Trade Journal
Publication Acceptance Date: 2/14/2014
Publication Date: 2/14/2014
Publication URL: http://www.vineyardteam.org/virtual-tailgates/pruning-diseases/
Citation: Baumgartner, K., Westover, F. 2014. Pruning for prevention and management of canker diseases. Trade Journal Publication.

Interpretive Summary: Trunk diseases (wood-canker diseases) threaten all California vineyards due to widespread distribution of the fungal pathogens. The infections are chronic and occur each year. Trunk diseases in mature vineyards reduce yields and increase management costs to the point where the vineyard is no longer profitable. This demonstration will help you identify trunk diseases and learn how to manage them through delayed pruning. We recommend that you start preventing trunk diseases before symptoms appear in young vineyards (less than 5 years old), beginning at the first dormant pruning. Trunk pathogens infect primarily through pruning wounds by rain-induced spore release during the dormant season in California. There are two approaches for pruning. One approach is to delay pruning until February or later. Pruning wounds made in early winter (December or January) are very susceptible to infection because winter rains induce spore release and cold temperatures lengthen the wound-healing process. In contrast, pruning wounds made in mid- to late winter (February or later) are at lower risk of infection because rain is less frequent and wounds heal soon after pruning. The other approach is double pruning, which is a type of delayed pruning for cordon-trained, spur-pruned vineyards. It involves two passes: Pass 1 (December or January) is often done with a mechanical pruning machine, canes are prepruned to about 10 to 12 inches above last year’s spurs; and Pass 2 (February or later), which is done by hand and canes are pruned to 2-bud spurs. This removes the section of the cane that may have been infected via pruning wounds made during Pass 1.

Technical Abstract: Trunk diseases (wood-canker diseases) threaten all California vineyards due to widespread distribution of the fungal pathogens. The infections are chronic and occur each year. Trunk diseases in mature vineyards reduce yields and increase management costs to the point where the vineyard is no longer profitable. This demonstration will help you identify trunk diseases and learn how to manage them through delayed pruning. We recommend that you start preventing trunk diseases before symptoms appear in young vineyards (less than 5 years old), beginning at the first dormant pruning. Trunk pathogens infect primarily through pruning wounds by rain-induced spore release during the dormant season in California. There are two approaches for pruning. One approach is to delay pruning until February or later. Pruning wounds made in early winter (December or January) are very susceptible to infection because winter rains induce spore release and cold temperatures lengthen the wound-healing process. In contrast, pruning wounds made in mid- to late winter (February or later) are at lower risk of infection because rain is less frequent and wounds heal soon after pruning. The other approach is double pruning, which is a type of delayed pruning for cordon-trained, spur-pruned vineyards. It involves two passes: Pass 1 (December or January) is often done with a mechanical pruning machine, canes are prepruned to about 10 to 12 inches above last year’s spurs; and Pass 2 (February or later), which is done by hand and canes are pruned to 2-bud spurs. This removes the section of the cane that may have been infected via pruning wounds made during Pass 1.