Issue link: http://winesandvines.uberflip.com/i/643683
42 WINES&VINES March 2016 GRAPEGROWING whether you use a cultivator like ours or a weed knife. A weed knife seems to require less horsepower, therefore less diesel, and can be driven almost twice as fast, from 2 mph to almost 4 mph. It costs us approximately $50 per acre per pass for our berm cultivator, and it costs us $22 per pass for our disc. Assuming four passes per season with the cultiva- tor and two with the disc, we are paying $244 per acre to control our berm weeds. This figure does not take into account the hours of weed trimming directly around the trunk of the vines where any form of mechanical cultivation seems to have issues. In contrast, we pay $75 per acre to unhook the drip hose off of the drip wire just before irrigation begins in late May. We pay another $75 to rehang the drip hose just before mechanical harvesting. This movement of the drip hose during irriga- tion allows us to cultivate only once under the vines, instead of six times. It also allows us to control the drip irrigation-induced weeds with cheaper mowing passes. Weed control is a challenge in high-wind- velocity areas in the (San Joaquin-Sacramento River) Delta. The standard for spraying to re- duce drift has been to stop our spray rigs once the wind speed has reached 10 mph. This win- dow of low wind typically occurs for about three hours in the early spring and summer mornings. Finding an employee willing to drive to work only to complete a three-hour shift is untenable. Tying up our tractors and spray rigs in wind-prone vineyards is equally uneconomical. For now, we have to rely on cultivation during the growing season, when it's gener- ally too windy to spray. We are in the process of building a prototype spray rig that will allow us to cover more ground in high-wind areas by creating an environment around the berms where wind speed is less than 10 mph. We will build a stainless steel spray compartment/shield that follows the contour of the ground with tracking caster wheels. This will allow us to keep the shield as close to the ground as possible. The compartment will be lined with brushes that reach to the ground, impeding any air from whipping under the shield. The spray nozzles will be oriented to spray the brushes instead of the weeds. The brushes will be saturated with herbicide and will wet the target weeds through wicking. This design will greatly reduce drift. Many of our design ideas have been adapted from sprayers we observed in New Zealand and Australia. This year we began another program that we hope will have some weed suppression merit. www.walterjelly.com 608.831.1405 whj wine print.indd 1 2/6/13 5:59:47 PM SOIL TESTING & ANALYSIS SUPPLIERS Company Phone Website Agri-Analysis LLC (800) 506-9852 agri-analysis.com Campbell Scientific Inc. (435) 753-2342 campbellsci.com Central Valley (707) 963-3622 central-valley.com CSP Labs (916) 655-1581 csplabs.com Decagon Devices Inc. (800) 755-2751 decagon.com Dellavalle Laboratory Inc. (800) 228-9896 dellavallelab.com Double A Vineyards Inc. (716) 672-8493 doubleavineyards.com Hanna Instruments (800) 426-6287 hannainst.com/usa Hortau (805) 545-5994 hortau.com Milwaukee Instruments (252) 443-3630 milwaukeeinstruments.com Ranch Systems LLC (415) 884-2770 ranchsystems.com Spectrum Technologies Inc. (800) 248-8873 specmeters.com Trimble Navigation Ltd. (800) 874-6253 trimble.com/agriculture/ viticulture For more information about the suppliers listed above, visit winesandvines.com/ buyersguide or see Wines & Vines' 2016 Buyer's Guide.