COTTON RESPONSE TO PLASTIC MULCH AND PLANTING DATES

Abstract

The effects of plastic mulch (with and without), three planting dates and five varieties (Deltapine 90, Deltapine 5415, Deltapine 5416, Stoneville 453 and Deltapine 80) on the productive response of cotton (Gossypium hirsutum L.) were evaluated during 1994 and 1995, based on yield (YLD), number of bolls (NB), indivual boll weight (BW) and plant height (PH). Lint percent (LP), fiber length (FL), fiber strength (RES), and fiber fineness (FIN) were added as lint quality variables in the second year. Plastic mulch (with black poliethilene 150 gauge) increased cotton yield (seed + fiber) in 36 %, NB in 27.8% and PH in 13 %; BW was unaffected. Planting dates did not affect yield notoriously, although BW, NB and PH had a better response in the first date. Varieties showed similar yields. Mulching lowered fiber length and strength, although fiber percent was increased. The best fiber quality was obtained in the third planting date, except in fiber percent which was higher in the first date. Plastic mulch shortened the harvest period by 22 days, as compared to the regional average period, for the first planting date. It is concluded that cotton yield is increased by plastic mulching, and that the planting date can be anticipated without yield losses, although fiber quality would decrease slightly. The best treatment combination was planting in the first two weeks of march covering the soil with black plastic mulch.