ABSTRACT

Studies were conducted during 1989-92 at the University of Florida Agricultural Research and Education Center near Jay, FL to evaluate both cultural and chemical tactics for weed management in cotton (Gossypium hirsutum L.). The factors evaluated included row spacing (30 in. vs 40 in. spacing), level of herbicide use, herbicide application method (band vs broadcast) and cultivation. The herbicide treatments were: none, fluometuron preemergence (PRE), pendimethalin + fluometuron PRE, pendimethalin + fluometuron PRE followed by cyanazine + MSMA directed postemergence, and hand-weeded. The experimental areas were infested with the annual grass species crabgrass (Digitaria ciliaris (Retz.) Keel.) and junglerice (Echinochloa colona (L.) Link) and the broadleaf weed species pigweed (Amaranthus sp.) morningglory (Ipomoea sp) sicklepod (Cassia obtusifolia L.)and cocklebur (Xanthium strumarium L).

Row spacing had no effect on weed control or crop yield. Cultivation significantly improved weed control and cotton yield for all treatments except with the most intense herbicide program applied broadcast. Herbicide application in a band followed with cultivation provided weed control equal to the broadcast application of the same herbicide program. A moderate level of herbicide (pendimethalin + fluometuron) followed by cultivation was comparable to the program with the highest level of herbicide (pendimethalin + fluometuron + cyanazine + MSMA). The results of this study indicate that herbicide use can be reduced by combining band application with cultivation to achieve an adequate level of weed control.