Issue link: https://read.dmtmag.com/i/662797
22 APRIL 15, 2016 Good Fruit Grower www.goodfruit.com Pre-emergents can help control yellow nutsedge Y ellow nutsedge can be a particular difficult weed to control in Northeast vineyards because of its below-ground germinating tuber, though the weed tends to disappear once a vineyard is established. Dr. Andy Senesac, Cornell University/Long Island Extension weed specialist, said the best strategy is to use pre-emergents. The newest tool available, and also the most potent, is Zeus Prime XC (sulfentrazone). Solicam (norflurazon) and Devrinol (napropamide) also have indicated activity against the weed. Another herbicide that can be effective is Matrix (rimsulfuron), Senesac said, which is labeled for potatoes, tomatoes and grapes. However, it is noto- rious for not getting into the plant when applied without an adjuvant. "You'll lose 20 percent of the control without one," he said. The herbicide also shows some activity against hedge bindweed, though the compound is not labeled for use against it. Thinking the need for adjuvants carried over to hedge bindweed, Senesac, conducted a trial applying Matrix to 6- and 12-inch hedge bind- weed stands. At various application rates with and without non-ionic surfactants, Senesac achieved 31 percent control without adjuvants and con- trol ranging from 74 percent to 99 percent with adjuvants. In a laboratory study, he evaluated hedge bindweed control using Matrix and Chateau and a combination of non-ionic surfactant, methylated seed oil and spray-grade ammonium sulfate as adjuvants. Senesac found Matrix, used in combi- nation with adjuvants, would suppress the weed's growth. —D. Weinstock appearance of a weed that has been controlled for years; annuals with a high level of seed production should top the list. Horseweed/marestail Mother Nature designed horseweed, also known as marestail, to take to the air and fly long distances. It's this ability that makes horseweed a distinctive threat. The other reason: This annual broadleaf is Roundup-resistant. Roundup-resistant horseweed bio- types developed in no-till, Roundup- ready corn 15 years ago. Seed spread is so widely dispersed, Senesac said, they are now scattered throughout the Midwest and Northeast. Each horseweed plant can produce 10,000 to 250,000 seeds. Roundup cannot control the weed's fall-emerging seed rosettes. There isn't a good pre-emergence option — even though there are several effective control products — because the main germina- tion flush does not begin until late sum- mer, making these products impractical or unpermitted, Senesac said. FOR ORGANIC PRODUCTION HERBICIDE EC SUPPRESS Herbicide EC is registered as a broad spectrum contact herbicide for post-emergent, non-selec ve weed control for use in cer fied organic crop produc on. • Has proven efficacy in over five years of university & field trials • Non-vola le, emulsifiable concentrate provides rapid weed control • Prevents weed resistance by rota ng with chemical herbicides in an Integrated Pest Management Program • Efficacy is comparable to conven onal herbicides • No pre-harvest interval Call today to learn more: www.westbridge.com • (800) 876-2767 ® Effective Organic Weed Control HERBICIDE EC HERBICIDE EC ® 4 hours post-applica on 72 hours post-applica on Treated Field