Tratamento químico e armazenamento de sementes de algodão

Abstract

High quality seed is one of the most important inputs that contribute to increase the profit of the cotton crop. Storage and chemical treatment are important procedures to maintain the quality of the seeds. The objective of this work was to evaluate the physiological performance of the seeds chemically treated along the storage and the control of pathogens. Seeds from Araçá BRS and FMT 701 cultivars were treated by the mixture of different fungicides and insecticides and stored in warehouse conditions. Samples were withdrawn in the beginning of the storage and every three months, when the following determinations took place: water content, germination, cooling, aging, emergence and sanity. Seeds treated chemically with mixtures of fungicides and insecticides during the storage presented superior germination and vigor than untreated. The treatments were efficient to control storage fungi. In another part of the work, seeds from Delta Opal cultivar were inoculated with C. gossypii and with C. gossypii var. cephalosporioides by the technique of the osmotic conditioning with PDA and manitol (-1,0 MPa). Subsequently, the seeds were treated by the fungicides Carbendazin +Tiram, Azoxistrobin + Fludioxonil + Metalaxil-M, Tolifluanid + Pencicuron, Fludioxonil, Carboxina + Tiram and Captana. Part of the seeds were not treated with fungicides. The physiologic and sanitary quality of the seeds were evaluated by the germination, cooling, emergence at tray and sanity tests. The best control of C. gossypii and C. gossypii var. cephalosporioides and better physiological performance were in the seeds treated with Carbendazin + Tiram; Carboxina + Tiram and Azoxistrobina + Fludioxonil + Metalaxil-M. There was no phytotoxic effect of the treatments applied on the cotton seeds.