WEED CONTROL IN NO-TILLAGE ZUCCHINI SQUASH PRODUCTION

A field study was conducted over two growing seasons (2000 and 2001) to determine the effect of preemergence (PRE) herbicides or combinations of PRE herbicides on control of smooth crabgrass and redroot pigweed in no-tillage ‘Independence II’ zucchini squash production. In 2000, clomazone + imazamox, clomazone + ethalfuralin, and dimethenamid resulted in sufficient weed control along with little crop injury/growth reduction and high squash yields. In 2001, the above mentioned herbicides except dimethenamid had the greatest potential for no-tillage squash production, as these treatments resulted in the best overall weed control while providing little crop injury/growth reduction and high squash yields. The clomazone and no-herbicide treatments tended to produce high early-season yields over both years; however, weed emergence and competition increased in these treatments over the production season, and tended to cause a yield decrease. Data collected over the 2000 and 2001 growing seasons indicate that clomazone + imazamox and clomazone + ethalfuralin resulted in the best overall weed control without having a detrimental influence on ‘Independence II’ squash yields in a no-tillage production system. In addition, these two herbicide combinations caused minimal or no effects on zucchini squash stand, squash growth, yield or maturity.