Industry Specialists Help Vineyards Protect Their Most Valuable Commodities
By: Cheryl Gray
In “The Wizard Of Oz,” Dorothy and her friends were afraid of lions and tigers and bears. For vineyards, danger lurks behind mealybug and nematodes and fungi. Oh my.
Insect pests and diseases can wreak havoc on vineyards, often causing irreparable and costly damage, destroying fruit, vines, even trunks – down to the root. That is why experts in managing these risk factors brandish prevention as their weapon of choice.
Atlas Vineyard Management
One such company is Atlas Vineyard Management, a Napa Valley, California, company founded in 2006. Its vineyard clients stretch from California to Oregon to Washington state. The company offers vineyard development, farming and viticulture services along with grape sales and marketing. AVM underscores what it describes as a successful track record of developing more than 2,000 acres of vineyards as proof that its pest and disease control methods are all built on best practices.
Madeleine Rowan-Davis is Senior Viticulturist for AVM. With degrees from the University of California at Davis and Mount Holyoke College, she is a certified Pest Control Advisor with a Qualified Applicator’s License, both through the state of California. As a former researcher at UC Davis, Rowan-Davis’ education and experience focus on sustainable farming. She pointed to one of the most dangerous insect pests to vineyards.
“The insect pest that incurs the highest costs per treated acre and poses a significant threat in the Northern California region, where we do a good amount of farming, is vine mealybug, which is arguably impossible to eradicate. Once it is present in a vineyard, it requires continued inputs to minimize spread into uninfected areas of the vineyard and prevent damage to the fruit.”
Rowan-Davis told The Grapevine Magazine how vine mealybug triggers multiple problems, including disease. “Not only can it damage the fruit by producing copious amounts of honeydew that results in the fruit being covered in sooty mold, but they also vector multiple strains of grapevine leafroll virus, which reduces the ability of the grapevine to ripen its crop. The plant cannot be cured once it is infected, so this can result in a lot of expense – ripping out & replanting infected vines – as well as lost revenue since it takes several years for the replanted vines to produce a crop. Because this pest has multiple generations in a single season, it can be particularly bad in warm growing regions where populations can multiply more rapidly.”
AVM offers its clients pest and disease scouting along with a customized management program. The company deploys spray programs that involve Integrated Pest Management principles, which it says minimizes chemical use while maximizing the effectiveness of sprays required to eradicate a problem.
“I would say that we advocate for management strategies to be well rounded,” said Rowan-Davis. “IPM guidelines are very helpful and allow us to minimize our reliance on chemical solutions while producing the highest quality wine grapes that a given site can produce. We use chemicals and management practices that are permitted in organic farming, even in our conventionally farmed properties.”
Like insect pests, there are diseases that affect some grape growing regions more than others, including leafroll and red blotch.
“These diseases are both caused by viruses and can dramatically impact the quality of the fruit,” Rowan-Davis said. “Grapevine viruses are moved around with planting material if one doesn’t follow safe practices, and many can also be vectored from vine-to-vine by insects or other pests. Red blotch and leafroll are found in many growing regions, but the severity of the disease can differ depending upon varying environmental stresses.”
When it comes to fighting the diseases and insects that can destroy a vineyard, education, backed by experience, matters.
Mark Greenspan, Ph.D., President and Viticulturist of Advanced Viticulture, Inc., has 30 years in the field, earning his Bachelor of Science in Electrical Engineering, Master of Science in Viticulture and doctorate in Agricultural Engineering, all from the UC Davis. He is also a certified crop advisor, certified professional agronomist and a licensed pest control advisor with the state of California.
Advanced Viticulture opened in 2005 as a technical consulting firm specializing in water and nutrient management, soil evaluations and vineyard design. Its vineyard clients are along California’s north and central coasts, across the U.S. and internationally. In 2011, the company expanded into vineyard management, providing services that include farming grapes and developing vineyards, primarily in Sonoma and Napa counties. Greenspan gave The Grapevine Magazine an overview of the damage caused by a range of insect pests.
“Spider mites can rapidly cause loss of leaf function and can retard fruit maturation as a result, if the infestation and damage become excessive. Nematodes weaken the vines overall and can eventually kill vines. The nematodes can spread in the soil and create weak and dead areas within a vineyard block,” he said. “All of these pests are found throughout grape growing regions of the U.S., but spider mites tend to thrive under hot, dusty conditions under periods of vine water stress. The West Coast experiences far fewer insect pests – and definitely diseases – than the East Coast and other grape growing regions of the U.S.”
According to Greenspan, some common diseases inflict significant damage to vineyards. “Powdery mildew is the most common and most damaging. It is fairly easy to control with fungicides, but the rotation of materials, timeliness, spray intervals and spray coverage is important for its control. This is a common problem in all growing regions. Trunk diseases are also very common and very damaging, and they include Eutypa and Botryosphaeria fungi, as well as Esca types of fungi. These are common in all regions and can damage a vineyard by killing the permanent structure of the vine.”
Choosing between either chemical or organic methods is about weighing outcomes. “We don’t advocate for either, but find that a mix of ‘chemical’ and organic materials is often the best approach,” Greenspan said. “Purely organic methods can be very difficult to make effective, especially for difficult pests like vine mealybug and spider mites. Fungal diseases are more readily treated using organic methods, but conventional materials are often more effective and require fewer passes through a vineyard to attain control. Also, it is not correct to label this ‘organic versus chemical.’ Organic products may be chemical as well but are derived from natural sources without extensive processing.”
Sym-Agro, Inc., based in California’s San Joaquin Valley, has developed new takes on what nature has to offer to combat insect pests and diseases plaguing vineyards. President and CEO Peter Bierma founded the company in 2012.
“I started Sym-Agro based on the belief that nature has antigens for every problem and, if you balance control with biology, you can grow really good crops with very little conventional pesticides,” said Bierma. “Now, with technology to validate [the] efficacy of essential oils, beneficial bacteria, etc., and more pressure on synthetic pesticides, this segment is growing very fast.”
Bierma, with three decades of industry and field experience, said Sym-Agro offers three specific products for grape crops: Cinnerate, Instill Copper and ProBlad Verde.
“ProBlad Verde provides excellent control of powdery mildew and botrytis. It is one of the few fungicides which has direct activity on all life stages of disease and provides 10-14 day spray intervals. Secondly, it is excellent for powdery mildew knockdown, stopping disease within four to eight hours and then providing control for 10-14 days.”
Cinnerate is a triple-action threat, Bierma said, acting as a miticide, fungicide and insecticide. Based on emulsified cinnamon oil, it is touted as a crop-safe but direct killer of all life stages of disease, including spores. Results come through either direct contact with the spray solution or through fuming activities. Used to reduce post-harvest rot through a pre-harvest application, Cinnerate is also a combatant against well-known insect pests, including mites, leafhoppers and mealybug.
Phomopis, powdery mildew and botrytis are the primary targets of Instill Copper, a low dose, liquid copper fungicide. Bierma told The Grapevine Magazine that Instill Copper leaves no visual residue on treated grapes and is safe to use throughout the growing season.
Suterra, a global leader for more than 30 years in pheromone insect pest control, creates products for use in six continents. In California alone, it provides services to an estimated 180,000 vineyard acres. Suterra is located in Bend, Oregon, where it houses research and development, pheromone synthesis, product engineering and manufacturing. Its parent company is The Wonderful Company, one of the world’s largest agricultural conglomerates and owner of wine brands that include Landmark, Justin and JNSQ.
Suterra products are available in multiple forms, including proprietary aerosol emitters, sprayable formulations, membrane dispensers and specialized monitoring lures. Its chief innovations are CheckMate VMB-F and CheckMate VMB-XL, touted as groundbreaking in the market. Sara Goldman, Technical Support Manager for Suterra, explained why these synthetic replicas of the sexual reproduction pheromones of vine mealybug are so formidable.
“By hanging VMB-XL dispensers or spraying VMB-F microcapsules, vineyard managers confuse flying male vine mealybugs so that they can’t find females to mate. This reduces the pest’s overall populations and is completely safe for all beneficial species and humans,” Goldman said. “CheckMate prevents damage and extends the lifespan of insecticides by mitigating resistance development. We also offer specialized lures to help Pest Control Advisors monitor for vine mealybug and grape mealybug.”
Goldman told The Grapevine Magazine that CheckMate VMB-F is more commonly used by conventional growers. It works with any IPM tools, from beneficial parasites and predators to conventional insecticides. That flexibility and compatibility make it a popular choice for vineyards defending against vine mealybug. An infestation, she said, can happen to even the most careful growers.
“Although the adult male vine mealybug can fly, the females and immature vine mealybugs, also known as ‘crawlers,’ are wingless and unable to fly. It is these non-flying life stages that spread the infestation into and through a vineyard in several ways. The most direct way is at planting through infested nursery stock,” she said. “Another common transmission method is through farm equipment. Do not allow contaminated equipment, vines, grapes or winery waste near un-infested vineyards. Mealybug crawlers can even hitch a ride on field crews that have been working in an infested vineyard or with prunings and plant residue from the previous season. They can also be dispersed by birds and other wildlife, surprising even the most meticulous growers.”
Once insect pests & diseases get out of control, both can create an uphill battle for vineyards. Experts say that for new vineyards, prevention starts with clean and disease-resistant plant materials. For mature vineyards, early detection and strategies developed by specialists who know best how to control and eradicate the threats can make the difference.