Protectant (contact) fungicides, such as the inorganics (copper, FRAC group M1) and sulfur (FRAC code M2); the dithiocarbamates (mancozeb, M3), phthalimides (Captan, M4), and chloronitriles (chlorothalonil, M5) are fungicides which have a low chance for fungicide resistance to develop. Protectant fungicides typically offer broad spectrum control for many different pathogens. Why wouldn’t fungi develop resistance […]
Continue reading...April 22, 2015 Andy Wyenandt
Spear Damage in Asparagus
Spear damage in asparagus can be caused by diseases such as Phytophthora spear and crown rot and purple spot. However, other environmental factors during the spring can damage spears as they emerge from the soil. Wind – Periods of heavy winds during emergence will cause spears to bend.Winds can cause one side of the spear […]
Continue reading...April 22, 2015 Andy Wyenandt
Vegetable Disease Briefs – 4/22/15
Quadris 2F from Syngenta, the first strobilurin (FRAC group 11) fungicide on the market, is coming off patent and a number of companies are expected to apply to manufacture and sell is under another name. Thus, in the 2015 Vegetable Recommendations Guide you will see references to Quadris (FRAC group 11) switched to azoxystrobin (FRAC […]
Continue reading...April 21, 2015 Andy Wyenandt
Vegetable Disease Update 4‑20‑15
This week in the Vegetable Disease Update: Asparagus Cabbage Cole crops Leeks Lettuce Note: The new 2015 NJ Commercial Vegetable Production Recommendations is available online. Asparagus Phytophthora crown and spear rot – In fields with low spots (poorly drained soils) or fields with a history of crown and/or spear rot apply Ridomil Gold 4SL (mefenoxam, […]
Continue reading...April 21, 2015 Andy Wyenandt
Controlling purple spot in Asparagus
Purple spot, caused the soil-borne fungus, Stemphylium vesicarium, can cause problems in cool, wet springs as well. Symptoms, just like its name, include numerous, sunken oval-shaped spots on spears during the harvest season and more importantly on ferns and stalks during the summer months as long as conditions are ideal for its development. Twelve hours […]
Continue reading...April 21, 2015 Andy Wyenandt
Suppressing Soil-borne Pathogens in Organic Transplant Production
Pathogens such as Fusarium, Pythium, Phytophthora, Thielaviopsis and Rhizoctonia that cause pre- and post-emergent damping-off can cause serious problems in organic transplant production. Remember, Phytophthora and Pythium are more likely to cause damping-off in cool, wet soils. Conversely, Rhizoctonia and Fusarium are more likely to cause damping-off under warmer, drier conditions. In general, Pythium tends […]
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