Trunk Neglect Is Too Common

riesling grapeTrunk or wood-canker diseases, including Botryosphaeria dieback, Esca, Eutypa dieback, and Phomopsis dieback, present a serious challenge to winegrape growers. Many vineyards in California are likely infected and yield losses in severely symptomatic vineyards can reach more than 90%. The overall economic impact of losses to Eutypa alone just in California has been estimated at 14% of gross producer value.

Trunk diseases take a long time to develop and often become symptomatic years after infection has already occurred, at which point management options are limited. While preventative management practices are available, grape growers may be hesitant to use them due to uncertainties about cost-effectiveness and future risk of infection.

Key Findings
Grape growers in the southern San Joaquin Valley, predominantly raisin growers in Fresno County, use both delayed pruning and pruning-wound protectants at relatively low levels for the prevention of trunk disease. For both practices, almost 40% of growers begin using the practice in vineyards older than 13 years. Growers rated pruning-wound protectants slightly more positively than delayed pruning for both maintaining yield and cost-effectiveness.

Methodology
We conducted a survey of attendees at the San Joaquin Valley Grape Symposium, organized and hosted by Matthew Fidelibus, University of California Cooperative Extension Specialist, held in Easton, CA, on Jan. 8. We used Turning Point, an electronic audience response system, to conduct the survey. UCCE Viticulture farm advisors and industry representatives helped design the survey. Up to 67 individuals responded to any given survey question.

Similar surveys are being conducted in other grape growing regions of California in the winter of 2013-2014. We are also conducting economic cost-benefit studies to better understand the long-term costs and benefits of different management practices in a range of scenarios. Combined, this research will provide us with a better understanding of the long-term efficacy of these management practices and the incentives motivating grower decision-making. We hope that this information will, in turn, provide growers and other managers a better understanding of how best to deal with trunk diseases.

trunk-neglect-figure-1-and-2Detailed Results
We asked raisin growers from the southern San Joaquin Valley about two practices known to be effective in preventing trunk diseases: delayed pruning and the application of pruning-wound protectants. We first asked growers how often they have used — or advised, for those in an advisory role — each of the practices in the last five years. As seen in Figure 1, growers use both delayed pruning and pruning-wound protectants at relatively low levels. Between 50-60% of growers never or rarely use these two practices.

We also asked growers what the typical age of a vineyard was when they first started using each (or advising) of the practices. Because these practices are most effective when used as preventative measures before infection occurs, the age of the vineyard at first use is an indication as to whether the practices are being used optimally. Symptoms typically become apparent in vineyards eight years or older, even when infection occurs much earlier. As seen in Figure 2, for both practices, about 40% of the growers reported typical first use to be in vineyards older than 13 years old. Thus a sizable minority of growers likely start to use these preventative practices after infection has already occurred.

trunk-neglect-figure-3Finally, we asked growers to evaluate the efficacy of each of the practices for two different criteria: maintaining adequate yield and cost-effectiveness. As seen in Figure 3, growers rated both practices mildly positively for both characteristics. Growers rated pruning-wound protectants slightly more positively than they did delayed pruning.

Topics: , , ,

Leave a Reply

Fruits Stories
drought management; irrigation; water management
FruitsHow To Become A Soil Sleuth
March 26, 2015
To correctly apply the proper nutrients at the right rates, you need to know where your fields are deficient and how to correctly diagnose a disorder. Read More
Cold ProtectionWind Machine, Electric Pruners Donated To MSU Research Center
March 25, 2015
New equipment to help protect research blocks from frost damage and provide center with latest technology. Read More
CitrusProposed Farm Bill Provision To Limit Payments To Non-Farmers
March 25, 2015
USDA has proposed a new rule which would limit payment to those who are only actively engaged in farming. Read More
Pennsylvania hard cider guild logo
Apples & PearsPennsylvania Hard Cider Producers Founded Independent Trade Organization
March 25, 2015
The Pennsylvania Cider Guild is designed to help promote and educate members and consumers. Read More
FruitsHow To Get Started With Partnerships And Sponsorships
March 25, 2015
Mark Saunders of Saunders Farm says your business is never too small or too big to get more value for what you do on your farm. Read More
FruitsValue Through Partnerships And Sponsorships [Opinion]
March 25, 2015
Mark Saunders of Saunders Farms says admission is one way to get value for what you do, but sponsorships and partnerships are the next level. Read More
chateau hough urban vineyard Cleveland Ohio
GrapesFrom Riots To Vineyard — A Story of Urban Revival
March 25, 2015
Ex-convict’s inner-city vineyard in the Hough neighborhood in Cleveland an opportunity for those leaving incarceration for a bright future in viticulture. Read More
The Latest
drought management; irrigation; water management
FruitsHow To Become A Soil Sleuth
March 26, 2015
To correctly apply the proper nutrients at the right rates, you need to know where your fields are deficient and how to correctly diagnose a disorder. Read More
Cold ProtectionWind Machine, Electric Pruners Donated To MSU Research …
March 25, 2015
New equipment to help protect research blocks from frost damage and provide center with latest technology. Read More
CitrusProposed Farm Bill Provision To Limit Payments To Non-F…
March 25, 2015
USDA has proposed a new rule which would limit payment to those who are only actively engaged in farming. Read More
FruitsHow To Get Started With Partnerships And Sponsorships
March 25, 2015
Mark Saunders of Saunders Farm says your business is never too small or too big to get more value for what you do on your farm. Read More
FruitsValue Through Partnerships And Sponsorships [Opinion]
March 25, 2015
Mark Saunders of Saunders Farms says admission is one way to get value for what you do, but sponsorships and partnerships are the next level. Read More
FruitsWorld Ag Expo 2015: New Tools For Fruit Growers
March 24, 2015
From wind machines to solar-powered pumps, here is some of the new equipment on display this year's edition of the nation's largest farm show. Read More
FruitsRare Leafhopper Found In Shipment At Delaware Port
March 24, 2015
This is the second time this pest has been discovered by U.S. Customs and Border Protection agriculture specialists. Read More
FruitsNew Pome, Citrus Thinning Tool Approved
March 24, 2015
Refine plant growth regulator receives federal registration. Read More
CitrusFarm Bureau Says WOTUS Rule Would Ignore Exemptions
March 24, 2015
Common farming practices may be vulnerable to Clean Water Act enforcement under the rule. Read More
FruitsUC-Davis Seed Biotech Center Receives Funds For Continu…
March 24, 2015
The university received $500,000 in funds toward a $2.5 million goal from seed company Limagrain. Read More
FruitsTips For Pear Psylla Management
March 24, 2015
Dormant oil applications should start as growers begin to experience warmer, mild weather. Read More
FruitsBiocontrols Event Draws Rave Reviews
March 23, 2015
Conference devoted to discussion of biological means to control pests and diseases held last month in Fresno, CA. Read More
brown marmorated stink bug dog search team
FruitsUSDA Uses Man’s Best Friend To Track Stink Bug
March 23, 2015
It's all paws on deck to find brown marmorated stink bug's overwintering sites. Read More
CitrusCalifornia Unveils $1 Billion Drought Package
March 23, 2015
Governor, legislative leaders, announce $1 billion emergency drought legislation. Read More
CitrusFeed A Bee Campaign Aims To Plant 50 Million Flowers
March 23, 2015
Bayer CropScience announces program to increase forage opportunities for critical pollinators. Read More
Florida organic strawberry research
FruitsParry America Aims To Boost Biopesticide Business Via S…
March 19, 2015
Brian Dockery tapped to drive growth of company’s specialty crop sector. Read More
Giant African Land Snail
CitrusFlorida To Get $7.3 Million To Fight Agricultural Pests…
March 19, 2015
Federal Farm Bill funding will bolster surveillance, detection, and identification of invasive threats to crops. Read More
FruitsStink Bug Predator Found In U.S.
March 18, 2015
Wasp native to Asia attacks brown marmorated stink bug eggs. Read More