Issue link: http://read.dmtmag.com/i/291333
S pecialty crops growers, especially those who grow grapes, will have new cause for concern in 2015 when new genetically modified crops are expected to come to fields near their orchards and vineyards. The new ones have been engineered to tolerate two additional herbicides, 2,4-D and dicamba, as well as the herbicides glyphosate (Roundup) or glufosinate (Liberty). Across the Midwest, where specialty crops grow like islands in a sea of corn and soybeans, more growers are expected to sign on and use the free Web site service called DriftWatch Specialty Crop Site Registry to identify areas growing crops that can't tolerate drift from spray- ing or movement of volatile herbicides. Hopefully, their neighbors and commercial applicators will visit the Drift- Watch Web site, see their posting, and take special care near their sensitive crops. Diane Brown, a Michigan State University extension fruit educator in Berrien County, where about 8,000 acres—nearly half—of the state's grapes are grown, is quite concerned. The herbicide 2,4-D has long been pub- lic enemy number one to grape growers, and Michigan has a public act, passed in 1963, forbidding use of 2,4-D esters in certain high-grape-acreage townships between May and October. The 2,4-D threat came from several sources. It was used sparingly in corn, since there was risk of injury, but it was widely used by homeowners, businesses, and golf courses to keep the lawns and turf free of broad-leaved weeds, especially dandelion. Brown is concerned about the possibility of vastly increased use of 2,4-D and dicamba, for two different reasons. 18 APRIL 15, 2014 GOOD FRUIT GROWER www.goodfruit.com Diane Brown, the extension fruit educator in Berrien County, Michigan, is concerned that herbicide-tolerant field crops will threaten grapes and other fruit. Field crops and specialty crops coexist all along the Lake Michigan shore. Ebony Rose Pluot® Royal Lynn Cherry Kylese-Cot Aprium® Dave Wilson Nursery (209) 874-1821 Fax 874-1920 Toll Free 800-654-5854 www.davewilson.com Far mer Proven ™ Since 1938 PHOTO BY RICHARD LEHNERT Herbicide-resistance RAISES CONCERNS Herbicide-tolerant field crops increase the risk of spray damage to neighboring fruit crops. by Richard Lehnert SOILS & Weed Control New HERBICIDE- RESISTANT crops B oth Dow Agrosciences and Monsanto Company expect to have new herbicide-resistant crops and new herbicides available in 2015. Dow is developing Enlist corn, which is resistant to both 2,4-D and aryloxyfenoxyproprionic acid herbicides used to control grasses, according to Diane Brown, a Michigan State University Extension educator. Enlist soybeans are resistant to 2,4-D, which will be stacked with both glyphosate- and glufosinate- resistant genes as well, which would also allow the use of glyphosate and Liberty herbicides on those crops. Dow Agrosciences will market Enlist Duo, for use on Enlist crops. It is a premix of glyphosate and a for- mulation of 2,4-D (2,4-D choline), which Dow claims is less volatile than 2,4-D amine. It could be avail- able for the 2015 growing season. Approval of Enlist crops has been delayed by the additional requirement for an environmental impact statement by the U.S. Environmental Protection Agency. Xtend traits are being developed by the Monsanto Company, Brown said. These traits confer resistance to dicamba herbicide, known under the trade names Banvel and Clarity. This would allow direct application of dicamba to soybeans to help address glyphosate-re- sistant weeds. To alleviate concerns about dicamba drift from fields of Xtend crops, BASF and Monsanto are developing a new formulation of dicamba with lower volatility than Clarity, which already has lower volatility than Banvel, Brown said. "Monsanto will sell a premix of glyphosate and the new formulation of dicamba under the prod- uct name of Roundup Xtend," she said. "The new dicamba formulation will also be available by itself under the product name of XtendiMax for Monsanto and Engenia from BASF." Xtend crop technology introduction has also been delayed by the additional requirement of an environ- mental impact statement. Xtend soybeans could be available in 2015, she said. New formulations of dicamba and 2,4-D are being developed with reduced volatility, but spray drift onto susceptible or nonresistant crops will still be a concern, she added. —R. Lehnert