By: Alyssa L. Ochs
Pests and plant diseases are inevitable if you’re in the business of growing any type of crop, but it’s how you handle those nuisances that really makes a difference in your production and crop quality. Fortunately, there are various methods available to vineyards for controlling common pests, such as insects, mites and parasites, as well as diseases specific to your region.
Common Vineyard Pests and Diseases
Depending on your vineyard’s location, you might experience many different types of pests throughout the year. Some of the most common pests that affect vineyards include grape berry moths, grape leafhoppers, Japanese beetles and rose chafers. Various types of mites, such as bud, rust and spider mites, often feed upon wine grapes, as well as mealy bugs and cutworms too.
Each of these pests affects grapevines differently but can cause significant damage if they aren’t identified and stopped at the earliest signs of feeding. In severe cases, pests can cause fruit to become so damaged that it cannot be used for winemaking. Malformed leaves, small leaves, less vine growth and reduced berry size are common after pest damage. Meanwhile, you might notice fewer grape bunches or leaves that are speckled and yellow after a pest infestation.
As with the pests themselves, diseases also vary widely depending on vineyard region and location within that region. For example, Pierce’s disease is especially problematic in California’s north coastal region. Powdery mildew and downy mildew are common pest-related grapevine diseases across the country, as well as black rot, botrytis bunch rot and phomopsis cane and leaf spot.
BioSafe Systems, LLC’s technical sales representative Taylor Vadon and technical marketing manager Patrick Clark told The Grapevine Magazine that powdery mildew and botrytis are some of the most common fungal diseases seen in vineyards today. They explained how powdery mildew is a devastating disease because this fungal pathogen can cause reduced vine growth, yield and fruit quality.
“The fungus can survive winter as chasmothecia, known as ‘resting spores,’ on the grapevine and nearby host sites, as well as mycelia infecting tissue inside dormant buds known as bud perennation,” they said. “Additionally, this fungus has been shown to have developed resistance to some commonly used fungicides.”
Control Methods for Vineyard Insects
Modern vineyards have a wide selection of chemical means at their disposal to control pests and keep plants as healthy as possible. For fungicides, it often takes a mixture of a couple different products for broad-spectrum control of multiple diseases. Yet it is often too late to wait until a fungus appears to apply fungicide. Insecticides in the form of cover sprays are popular among vineyards that like the convenience of an air blast sprayer and option to mix fungicides in the tank when desired.
Ryann Greenleaf of A1 Mist Sprayers, an application equipment company based in Ponca, Nebraska, told The Grapevine how these mist sprayers are great for coverage efficiency because they deposit the droplets of whatever product is applied to the underside of the leaf. Meanwhile, most other machines strictly apply product to the top of the foliage.
“A1 Mist Sprayers are also a more cost-effective piece of equipment and can be used for fungicides, insecticides and foliar fertilization applications.” Greenleaf said.
“The 3PT Terminator is our most recommended product for a vineyard because of the applied coverage of a product, it is the best ‘bang for your buck’ and it has additional attachments that can be purchased that have been designed specifically with a vineyard situation in mind, such as the 2-Way Orchard/Vineyard Volute and the 11-Nozzle Vertical Volute,” Greenleaf said. “Our next recommended product is the Boss mist sprayer. This is a smaller, more compact and price efficient model that is ideal for smaller operations and also has a Vertical Volute option.”
Control Methods for Vineyard Diseases
To control vineyard diseases, Dr. Melissa J. O’Neal, the product development manager for the Western United States for Marrone Bio Innovations (MBI), recommends using preventative sprays to strengthen the plant’s immunity.
“Integrated pest management (IPM) programs combine chemical, biological, cultural and other control methods to manage grapevine pests,” Dr. O’Neal said. “All products in the MBI portfolio can be rotated or combined with chemicals. The latter approach is the foundation of MBI’s BioUnite approach, which provides growers with IPM programs that harness the power of biology with the performance of chemistry, resulting in a more efficient food production system that is affordable, sustainable, safe and easy to use.”
“Regalia Biofungicide is used early for disease prevention and overall plant health and through the season for continued disease control,” said Dr. O’Neal. “Stargus Biofungicide is an advanced SAR and ISR biofungicide targeting key diseases of grapes. Increases in yield have been observed when either Regalia or Stargus are included in grape disease management programs.”
Dr. O’Neal said, “Grandevo contains several active compounds that repel, stop feeding, reduce reproduction and induce mortality to prevent the development of damaging populations of sucking and chewing insects, flies and mites. Venerate XC is a broad-spectrum, in-season insecticide with a similarly broad label. Finally, Haven is an abiotic stress manager that helps crops dissipate excess heat and moderates solar radiation, preventing heat and sun damage while increasing photosynthesis, as well as marketable yield.”
To best combat fungal diseases and manage development of fungicide resistance, Vadon and Clark of BioSafe Systems recommend preventative actions, such as dormant applications and continued measures throughout the growing season to protect plant tissue by reducing spores and inhibiting fungal development.
“The use of fungicidal products, like OxiDate 5.0 and PerCarb, play a key role in reducing disease pressure by eliminating fungus and their spores,” said Vadon and Clark. “Sound cultural practices interwoven with quality fungicide applications that utilize rotating modes of action, plus low to no resistance potential, are very important to sound vineyard disease management practices that protect the health of the vine, improve quality of the grapes and advance the sustainability of the vineyard.”
Vadon and Clark shared that recent results from a UC Davis study last season, showcased the effective use of OxiDate 5.0 in a BioSafe Systems program for grape powdery mildew, demonstrating leading significant performance for control of the disease amongst multiple industry standard programs.
Meanwhile, Semios is a scalable, data analytics platform that uses precision agriculture technology to help predict, identify and prevent pest and disease pressure. With company offices in California, Washington and British Columbia, Canada, Semios aims to help growers worry less through automated and remotely controlled climate, insect and disease monitoring treatment.
“We believe that data, direct from the vineyard, combined with dynamic modelling enables the most efficient, effective and targeted approach to managing grapevine diseases, like powdery mildew,” James Watson, the director of sales and marketing for Semios, told The Grapevine Magazine.
“When the appropriate action is taken with optimal timing, growers can improve results, while additionally mitigating the possibility of resistance due to overuse of control products,” Watson said. “Tools like Semios can be a powerful ally when growers are seeking improved economies in management practices and their customers are pressuring them to adopt more sustainable practices.”
Semios’ primary product available for vineyard management is its industry-leading grape powdery mildew model, which Watson said provides growers and consultants an index value with up to per-acre granularity that is computed inside the vine canopy. He said that this stands out from common commercial models that rely on climate data gleaned from a handful of weather data sources outside of the vineyard.
“Due to this unique, granular evaluation, growers and PCAs get a modelled sense of the probable location of disease risk hotspots in the vineyard at any time,” Watson said about Semios’ advantageous capabilities. “This can save critical time when scouting and assessing disease risk, while simultaneously informing a management strategy for optimal response and effectiveness of treatment.”
Timing and Other Considerations
As a general rule, many vineyards apply pest control methods when shoots are an average of five inches in length. After almost all of the florets have bloomed, consider applying a post-bloom spray. It is also a wise idea to apply pesticides before rainy periods so they have an opportunity to dry before the rain comes. In fact, weather conditions have a big impact on not only control applications, but also how many pests and diseases affect a vineyard during the year.
“Pest control is really dependent on what part of the world you live in and when the pests from your region are more active,” said Greenleaf of A1 Mist Sprayers. “However, using an A1 Mist Sprayer allows you to use the unit anytime of the year that the pests are being a nuisance and should be used year-round to not only eradicate a pest problem, but also help in the prevention of pests, including powdery mildew, downy mildew, black rot and fruit rot.”
Vadon and Clark of BioSafe Systems pointed out that many fungal disease pathogens are in a vineyard throughout the year, which means that vineyard managers should always stay vigilant with their management practices. It is essential to monitor vines for diseases leading up to and at bud break but also to be prudent heading into bloom until bunch closure.
“During the fruit set and early fruit development, vines are actively photosynthesizing and directing nutrients to growing points and developing clusters,” said Vadon and Clark. “These specific growth stages, coupled with potentially humid conditions and mild temperatures, can produce the ideal breeding ground for fungal diseases, such as powdery mildew, downy mildew and botrytis. During this period, it is vital to manage fungal pathogens and their spores with proven products, especially leading into bunch closure to ensure a healthy cluster.”
Watson of Semios said that the ideal timing and frequency of pest and disease control measures vary considerably depending on a vineyard’s region, historical pressure, pathogen and variety.
“Semios is ‘always on’ and provides the advantage of feeding proven disease tracking models, developed by trusted university researchers, with the most accurate and representative data,” Watson said. “Field data is updated every ten minutes, ensuring the most accurate insights when most needed. Timely identification and location of the risk via heat maps and automatic mobile alerts helps speed scouting and treatment decisions.”
Safety When Using Pesticides and Fungicides
Pesticide and fungicide use does not come without risks, so it is always best to accurately identify grapevine intruders before applying a new product. Use a minimal amount of a product to gauge effectiveness because more is not necessarily better when it comes to pest and disease control.
Read product labels carefully, store products in their original containers until they are empty and stay away from sprayed areas until they are dry. Also, check local regulations for pesticide and fungicide use to ensure you are in legal compliance before applying a new product.
Dr. O’Neal of Marrone Bio Innovations advises vineyard managers and staff to always read and follow label instructions, wear the proper PPE and consider using only products with a favorable safety profile.
“MBI portfolio offerings represent resistance management tools in a grower’s IPM program,” said Dr. O’Neal. “In addition, all products in the MBI portfolio offer growers sustainable modes of action which combat resistance development. MBI products have a favorable safety profile, with four-hour re-entry intervals and zero-day pre-harvest intervals. In addition, MBI products are reduced risk, are tolerance exempt, and all of them except Haven are OMRI-certified.”
Tips and Advice About Pest and Disease Control
Experts who work in with pests and diseases every day can offer practical advice to save you time, money and hassles in vineyard management.
“In general, predictive disease models were developed through research using micro-climate weather data collected in the vineyard,” said Watson of Semios. “Unfortunately, most current disease monitoring solutions don’t accurately measure in-canopy conditions, resulting in reduced accuracy and effectiveness of the model itself. It is important when using technology to assess disease risk to ensure that the source of the data that drives the calculations originates in the canopy of the vineyard itself, which can then speed assessment and treatment for improved results.”
Dr. O’Neal from Marrone Bio Innovations advises vineyard managers to always keep in mind the holistic mindset.
“Pest and disease management are continual tasks that extend beyond the growing season,” she said. “These tasks require year-round planning, program revision and continual research of the newly emerging management tools available. In the present agricultural landscape, managers will likely need to utilize a combination of biological, chemical, cultural and other management tactics.”
Vadon and Clark from BioSafe Systems said that the most critical advice for vineyard managers regarding disease management would be to stress the importance that they must be proactive and not reactive. There is some truth to the old saying that “an ounce of prevention is worth a pound of cure” because a robust and comprehensive preventative management program, in conjunction with good cultural practices, will mitigate many disease issues seen during crucial times of the growing season.
“Products, like Oxidate 5.0 and PerCarb, are perfect additions to a strong preventative management program, because they are cost-effective with broad-spectrum activity, have no known resistance and can be applied tank-mixed or stand-alone,” said Vadon and Clark. “Using these two products throughout the growing season will eradicate fungal spores and mycelium on contact, reducing disease pressure and thus preventing disease outbreaks and the buildup resistance.
“The best advice we can give is to start a prevention plan as soon as possible and to stay on top of that problem with a regular schedule of applications,” said Greenleaf of A1 Mist Sprayers. “It is very important to do your research on the pest, the chemical or natural solution for that pest and the equipment to apply it with.”
