| Popis: |
The increased adoption of conservation tillage in vegetable production requires more information on the role of various cover crops in weed control, tomato quality, and yield. Three conservation-tillage systems utilizing crimson clover, turnip, and cereal rye as winter cover crops were compared to a conventional black polythene mulch system, with or without herbicide, for weed control and tomato yield. All cover crops were flattened with a mechanical roller/crimper prior to chemical desiccation. Herbicide treatments included a PRE application of S-metolachlor (1.87 kg a.i. ha−1) either alone, or followed by an early POST metribuzin (0.56 kg a.i. ha−1) application followed by a late POST application of clethodim (0.28 kg a.i. ha−1). Except for spotted spurge and tall morningglory only the main effect of herbicide treatments and cover crops affected weed control. For the majority of the weeds, no significant differences in weed control were observed with rye residue and plastic mulch treatments; however, turnip and crimson clover residue failed to control most weeds. Rye residue provided 86% large crabgrass, 80% goosegrass and 84% Broadleaf signalgrass control. Yellow nutsedge was controlled 65% by plastic mulch and only 60% by Rye residue. Pokeweed was controlled 80% by plastic mulch treatment. S-metola‐ chlor applied PRE was sufficient in controlling leafy spurge and tall morningglory in plastic mulch and rye residue plots. Yield was less following either crimson clover or turnip cover crops compared to rye or the polythene mulch system. Application of herbicides resulted in better yields compared to the no-herbicide treatments. Economic analysis indicated that there was no significant difference between using a rye cover crop or plastic under any of the alternative herbicide treatment regimes in 2005. This research demonstrates the possibility of growing tomato in conservation tillage systems using high residue cover crops and herbicides to maintain season long weed control. |
