Performance of cotton genotypes in the state of São Paulo: yield, disease resistance and fiber quality

In the 2001/02 growing season 16 field experiments were conducted in the main cotton producing regions of the state of São Paulo to evaluate the performance of 12 cotton genotypes for yield, fiber quality and resistance to six diseases of the crop. A randomized complete block design with four replications, which were represented by two five-meter-long rows now used. Substantial differences between genotypes were observed for both cotton seed and fiber. Although outstanding in some genotypes, the fiber percentage was not a determining factor of fiber yield per area. Among the 12 genotypes studied, only 'CNPA ITA 90' and 'BRS IPÊ' presented good index of resistance to the ramularia. On the other hand, 'IAC 24' presented good index for Fusarium, nematodes and ramulose, the three more destructible diseases.Most of the evalueted cultivars and lines were susceptible to one or more diseases; none of them showed multiple resistance to all diseases.

Gossypium hirsutum; yield; pathogens