Submitted to: Southern Conservation Agricultural Systems Conference
Publication Type: Proceedings
Publication Acceptance Date: 7/20/2010
Publication Date: 7/20/2010
Citation: Kornecki, T.S., Price, A.J. 2010. Effects of rolling/crimping rye and clover with different herbicide types and rates on their termination rate, cotton population and yield in a no-till system. In: Endale, D.M., Iversen, K.V., editors. Proceedings of the 32nd Southern Conservation Agricultural Systems Conference, July 20-23, 2010, Jackson, Tennessee. CDROM. Interpretive Summary: Three different herbicides: glyphosate (RoundupTM) Weed-Zap, and vinegar 20% were applied continuously, every second, and every 3rd crimp on rolled/crimped rye and crimson clover. Results indicate that one week after rolling, the highest rye termination rates were recorded for glyphosate continuous spray (97%) for spray every 2nd crimp (96%) and every 3rd crimp (96%). Organic herbicides (Weed-Zap and vinegar) and roller/crimper alone generated between 90 and 93% rye termination which was at the recommended termination level to plant a cash crop into residue rye cover. Contrary to rye, termination rates for crimson clover was lower, and one week after rolling, glyphosate application generated only between 38 to 41% termination. By third week after rolling, the highest termination for clover was observed with all glyphosate treatments (92 to 98%) which exceeded recommended termination to plant cash crop into this cover. Other treatments resulted between 81 and 86% clover termination. Cotton population was neither affected by cover type nor was treatment averaging 40,897 plants ac-1. Cotton seed and lint yield was significantly higher for rye residue producing 3,110 lbs ac-1 compared to 2,554 lbs ac-1 produced by crimson clover (18% lower). This reduced yield may be associated with increased vegetative growth of cotton. Cotton plants following crimson clover (49.2 inches) were taller than following rye (43.7 inches). These results only represent one year, so we need to observe during the next two years to see if the same trends continue. If so, using crimson clover as a cover crop in no-till cotton may not be advantageous due to reduced termination rates. However, for no-till/organic vegetable utilizing crimson clover may benefit selected vegetables.
Technical Abstract: In 2008, a field experiment was initiated in central Alabama to study the effects of terminating rye and crimson clover utilizing rolling technology and three different types and application rates of herbicides on cover crops termination rates, cotton population and yield. A two stage roller/crimper with and without supplemental application of glyphosate or two organic herbicides (Weed-Zap and vinegar 20% acidity) applied as a continuous spray, every second crimp and every third crimp controlled by a high speed solenoid valve nozzle system were used to terminate rye and crimson clover. Cover crop termination rates were assessed at rolling, one, two, and three weeks after rolling. In 2009, three weeks after rolling, complete termination rate was achieved with rolling/crimping and glyphosate treatments (96-99%). Organic herbicide treatments generated between 91-94% terminations. Rolling treatments and cover crop type had no effect on cotton population which averaged 40,987 plants ac-1. However, significantly higher average seed cotton yield of 3110 lbs ac-1 was reported for rye cover crop compared to 2,545 lbs ac-1 for crimson clover.