Efeito de três descaroçadores sobre danos mecânicos, qualidade da semente e tecnológica da fibra de duas cultivares de algodão.

Abstract

Ginning is the strategical stage in the chain productive of the cotton, consisting of a series of mechanical and thermo-pneumatic processes, composed of drying, cleanness and extration of fiber from the cottonseed, being this last one, used in the industry of the wiring. The present work was developed to evaluate the effect of the gin machines of 50 and 80 saws in comparison with a roller ginning in the mechanical damages, seed physiological quality and fiber technological quality. In this study, two cotton varieties had been analyzed (BRS 187 8H and BRS 200 Marrom), two types of seeds (linted and non linted) and three periods of storage (0, 3, 6 months). After the ginning processes, a lot of seeds was submitted to the process of chemical delinting; after that carried through the physical purity, mechanical damages, germination and vigor, in the Seed Laboratory of the EMBRAPA Cotton. Another one was stored by 6 months in the environmental conditions of the Patos Experimental Station Laboratory of Embrapa Cotton, PB, without no control of temperature and relative humidity of air. The cotton fiber of each treatment had been sent for the Fiber Laboratory of the EMBRAPA Cotton, Campina Grande, PB, where its main characteristics had been measured (micronaire, length, uniformity, index of short lints, index of reliability, resistance, and allonge), through the automatic system of HVI (High Volume Instruments). The adopted statistical delineation was completely randomized with the treatments distributed in factorial arrangement. By means of the results one concludes that: the ginning equipments of saws had presented greater mechanical income of physical purity of the seeds and damages classified as light; lesser percentage of viability in the seeds gotten in the gin machine of 80 saws; the viability of the lintered seeds was superior to the non-lintered; the ginning machines of saws had increased the short staple fiber index in the herbaceous cotton (white) and half perennial (coloring); the fiber resistance of the herbaceous cotton was not affected by the ginning equipments tested; the colorful fiber allonge was not affected in the two processes of removing seeds, but for the white cotton if it got the biggest values in the ginning of 80 saws; the BRS 187 8H cultivar presented the best results for inner cotton fiber characteristics. It was also observed that the gin machines of saws cut the fiber of the cotton more than the roller ginning.