Integrating Herbicide and Cover Crop Management for Cost Effective Results.
By: Kevin Martin, Penn State Extension Educator (Portland, NY)
We are starting to see increases in herbicide management costs. Some of you know all to well that 1-2 applications of herbicide do not provide adequate control of weed competition in vineyards. Complicated tank mixes that cost over $100 per applied acre are not a practice I would consider sustainable. Some growers, though, would disagree.
The cost of materials are not increasing substantially. More frequent applications and a need to apply better materials more often is driving costs up. The majority of herbicides used by growers are off patent these days and available almost exclusively in generic form. A third or even fourth vineyard pass, could be sustainable. The cost of materials and materials selected needs to be looked at comprehensively with the number of passes required to obtain adequate control.
There may be a potential for cover crops to improve the effectiveness of weed control. We can observe this not just in row middle management, but to a lesser extent under trellis management. Cover crops do not offer the potential to reduce herbicide applications in situations where growers are applying between 1 and 3 per year. Rather, they offer an option to improve results without adding an additional pass. This is because cover crops can reduce vine size when row middle competition is undesirable. In 2016 field trials we observed smaller berry size when cover crops were planted in the late summer of 2015 and were not terminated before June 1, 2016. Particularly where hard to control species get established, some growers have added a late summer or fall application to bring their total number of herbicide application to 4-5. In this scenario, the right cover crop mix offers the potential of superior control with one less pass. Cover crops do require some form of termination (usually chemical). By selecting the right species, a low rate of round-up may offer excellent row middle control.
Cover crop mixes being trialed are similar in cost to an herbicide application. Low-end rye grass and radish blends are comparable to many post emergent row middle applications. Higher end seed mixes with oats, more radishes or even buckwheat range between $12 and $15 per seeded acre in materials. Legumes increase costs but potentially reduce fertilizer use. Easy to kill hybrid crimson clover complicates the economic analysis. It may reduce urea applications by 50%, but could be more difficult to grow. Understanding effective seed mixes, their primary benefits and potential secondary benefits will be key to the success of moving cover crops into perennially systems in a cost-effective (saving) way. Regional differences in seed prices also complicated the matter. One of our primary suppliers of cover crop seeds in the Lake Erie Region is Ernst Seed Co. 2016 prices were used to calculate the cost of various seed mixes used in trials.
LERGP, led by Luke Haggerty, is taking an integrated look at cover crops in Concord vineyards. As he observes benefits, I’ll help quantify them. There is a lot we still do not know. While preliminary results show promise for increasing economic sustainability where herbicide program prices are spiraling upward, a few years’ worth of data will allow us to clearly observe measurable benefits in herbicide programs. Right now, it just seems like there are less weeds and more cover crop in row middles that have been seeded.
 Tang, Yijia, Miguel I. Gómez, Gerald B. White. COST OF ESTABLISHMENT AND PRODUCTION OF HYBRID GRAPES IN THE FINGER LAKES REGION OF NEW YORK, 2013. Cornell, Dec. 2014, http://publications.dyson.cornell.edu/outreach/extensionpdf/2014/Cornell-Dyson-eb1411.pdf Accessed 3 Nov. 2016.
 Bowman, Greg, Craig Cramer, and Christopher Shirley. Managing Cover Crops Profitability. 3rd ed.: Sustainable Agriculture Research and Education. SARE, July 2012, http://www.sare.org/Learning-Center/Books/Managing-Cover-Crops-Profitably-3rd-Edition Accessed 3 Nov. 2016. pp. 394.
 Id. At 122 – 124.