App aims to help grape growers address problems

Most growers, pest control advisors and the like know the drill when they gather for a workshop. First order of business: Please silence your phones.

But that wasn't the admonishment that opened a San Joaquin Valley Winegrowers Association meeting on a mobile phone app called The Vineyard Advisor.

Presenter Ed Hellman, professor of viticulture and enology at Texas Tech University, suggested participants take out their phones and consider downloading the app on their Apple or Android devices.

The app addresses 360 grape problems nationwide, including diseases, insect and mite pests, wildlife pests, environmental stresses, physiological disorders and weeds.

It has a huge database on registered pesticides and can let users know if a given pesticide is registered for use in their state. Disease management information includes control strategies and action thresholds, natural control and cultural practices, organic material, references and additional resources.

Users can search for a "grape problem"—for example, powdery mildew—or a given grape pesticide or active ingredient.

A search for grape powdery mildew gives information that includes a link to a powdery mildew disease risk assessment index and the Fungicide Resistance Action Committee, which has classified fungicides by mode of action and resistance risk and assigned a FRAC group number.

The risk assessment index can be tapped to find out the degree to which powdery mildew's development may put the vines at risk. If it's deemed high, with production every five days in a given region, it would be best to plan a fungicide application sooner than if it's moderate, with reproduction every 15 days.

Hellman used the index to check out the risk in the Kearney Agricultural Research and Extension Center area in Parlier.

The app gives advice on avoiding selection of a fungicide that would contribute to resistance and has a link on fungicide efficacy tables. It has advice on organic materials and provides warnings that some grape cultivars are sensitive to sulfur and to not apply sulfur and oil products within 10 to 14 days of each other.

Hellman pointed out the app shows 410 products registered for grape powdery mildew. The pesticides can be searched by name or by active ingredient. The app's user can find if a product is labeled for use in their state. If it has been canceled, that will be noted. Also, a PDF of the full pesticide label can be called up.

Other common California diseases in the database include armillaria root rot (oak root fungus), botryosphaeria dieback, botrytis bunch rot, crown gall, downy mildew, esca (black measles), eutypa dieback, phomopsis cane and leaf spot, Pierce's disease, summer bunch rot (sour rot) and viral diseases.

Insect management information includes control strategies and action thresholds, natural control and cultural practices, organic materials, references, registered pesticides and additional resources.

Under weed management information are special considerations, cultural practices and general recommendations, organic practices and materials, references, registered pesticides under preemergence herbicides and postemergence herbicides, and additional resources.

Environmental stresses include smoke taint, pinot leaf curl, sunburn or heat injury, spring frost or freeze injury, hail injury, fall frost injury and salt toxicity.

Physiological disorders that are considered include "hens and chicks" (millerandage) when a grape bunch contains berries of different sizes and levels of maturity, coulure (berry shatter), early bunch stem necrosis, spring fever and berry shrivel.

There's also a grouping of emerging problems that includes smoke taint, grapevine red blotch, spotted wing drosophila, brown marmorated stinkbug, European grapevine moth and spotted lanternfly.

Toby O'Geen, University of California, Davis, professor and soil resource specialist, talked about the UC Davis California Soil Resource Lab and SoilWeb apps that may be used to access detailed soil survey data from the U.S. Department of Agriculture and the National Cooperative Soil Survey.

The app uses an interactive Google map and runs in a web browser and is compatible with desktop computers, tablets and smartphones.

Also available are the Soil Series Extent Explorer, the Soil Agricultural Groundwater Banking Index that may be used to identify the suitability of soils for on-farm groundwater recharge in California, SoilWeb Earth and Soil Properties.

Information that can be quickly accessed includes composition of the soil, ponding frequency, available water storage and drainage classification. It can also provide pH information and profiles of the soil that show organic matter, clay and sand content and more.

It can also show levels of electrical conductivity, water holding capacity, erosion, runoff and drainage, and whether a given area is suitable for farming.

(Dennis Pollock is a reporter in Fresno. He may be contacted at agcompollock@yahoo.com.)