Terminação do crescimento do algodoeiro seu efeito na produtividade e qualidade de fibra em sistemas de preparo de solo

Abstract

Soil tillage systems affect edaphic conditions and vegetative and reproductive development of the cotton plant, and may modify the time of the plant's growth termination (cutting) with growth inhibitors. The aim of this study was to evaluate the effect of the cutting time (69, 86, 101 DAE and without cutting) on the yield and quality of cotton fiber cultivated in conventional (SSC) and direct (SSD) sowing systems in the 2019/20 and 2020/21 seasons. SSC plants had 33% higher height (105 cm) and one node more than SSD. Height was 3% higher when the cutting occurred at 86 and 101 DAE. In 2019/20, the number of cotton bolls (NC) was 18% lower than in 2020/21, which resulted in lower yield this year. The NC in the SSC was 14% higher than in the SSD (95.24 m-2). In addition, growth termination at 86 and 101 DAE resulted in a 10% increase in NC. SSC yield was 13% higher than SSD. The cotton growth termination at 86 and 101 DAE resulted fiber yield average of 1711 kg ha-1, 11% higher than when the termination at early (69 DAE) and/or when it was not performed. Termination at 69 and 86 DAE improved micronaire and fiber maturity. It is concluded that the termination of growth at 86 DAE improves yield without impairing fiber quality, and in adverse years the SSD provides greater retention of bolls.