Italian ryegrass is a major weed in orchards, vineyards, field crops, and fallow fields of California (Figure 1). Several different herbicides are used to control ryegrass and had been effective in reducing infestations until resistance evolved in many populations following repeated use of the herbicides. To date, resistance to glyphosate, paraquat, and some ACCase and ALS inhibitors has been confirmed …

Drosophila and Sour Rot Management University of Georgia Viticulture Extension — I just wanted to alert everyone that spotted wing drosophila (SWD) management timing is approaching soon. The SWD flies are active nearly year round in these parts, but near veraison as the brix levels in wine grapes reach approximately 15 degrees Brix, the grapes become attractive (and thus susceptible) to SWD. While …

White, yellow or brown blotches on fruit raise alarm bells, but they may be sunburn rather than a disease or chemical injury. This article lay out clues to identifying fruit damage as sunburn or another issues. Hot weather, strong sunlight, and low humidity are a recipe for sunburn on fruit crops. But another key ingredient is at play here too, …

Veraison has been spotted on grape clusters from the Horticultural Research Center in Chanhassen to Les Curry’s Marquette vines in Amboy. You know what that means: It’s almost bunch rot – err, I mean – harvest season! Key grape bunch rot diseases to look out for in Minnesota include botrytis bunch rot, sour rot, and phomopsis. Another non-disease related fruit …

Pinot leaf curl (PLC) is a physiological disorder of wine grapes marked by characteristic foliar symptoms early in the season. It may be associated with a disruption of healthy nitrogen metabolism in developing shoots. Although its incidence tends to be episodic, PLC symptoms were reported in Southern Oregon in Spring 2019 and have resurfaced (to a lesser degree) in Spring …

Japanese beetle numbers continue to increase in the weekly trap counts conducted by University of Minnesota researchers in Forest Lake, Hastings, Chanhassen, and Rosemount. As infestations increase on farms, growers should be vigilant about control in order to prevent extensive leaf damage. Review of Pesticide Options for Japanese Beetles Japanese beetles release an aggregation pheromone to attract others. Therefore, early control is …

The two diseases discussed below have one thing in common, both Sour rot and Bitter rot can infect grape berries in which the skin has been compromised. That is their only commonality. Bitter Rot Over the past couple of years, the incidence of Bitter rot appears to be increasing at least by visual observation. In many cases, Bitter rot seems …

The climate in New York state is ideal for cultivating many grape varieties but also makes the region a breeding ground for pathogens such as grape downy mildew disease. While pesticides are commonly used to help control it, the pathogen is beginning to develop resistance to a group of fungicides commonly used in East Coast vineyards. A new project led …

Fungal pathogens, like the ones present in many specialty crops, often change over time. This means, for example, that resistance to certain fungicides might also vary from year to year. Improved knowledge about which types of pathogens are present will allow growers to invest in the most cost-effective disease management strategies. Timothy Miles, assistant professor and Extension specialist in the …

Many of the fungicides utilized for Botrytis management are no longer efficacious due to resistance development in this fungus. Now is a great time to collect Botrytis samples for fungicide-resistance testing. While the funds last, Botrytis resistance testing is free for wine grape producers in most of the Southeast (Alabama, Arkansas, Georgia, Louisiana, North Carolina, South Carolina, Tennessee, and Virginia) …