Deslintador mecânico-químico de sementes de algodão: desenvolvimento, avaliação e estudo do efeito latente do deslintamento das sementes durante o armazenamento.

Abstract

After the cotton beneficiation process, seeds retain a covering of short fibers, so-called lint, which hampers their management at planting and also in performing the phytosanitary treatment, since the seeds adhere to each other, by generating an agglomerate which complicates the distribution within the row and effectiveness of the phytosanitary treatment, in addition to allowing the transport of pests and diseases. Aiming to improve the quality of seeds for planting, the Ministry of Agriculture, Livestock and Supply (MALS) established Ordinance prohibiting the trade of cotton seed with linter. The delinting consists in removing the linter from the cotton seed, through various processes but the chemical method, the one which uses sulfuric acid, is the most used, which is based on putting the seed into contact with the acid during for a time. But in the Northeast region, there is a notorious lack of delinting equipment, by needing the seeds displacement to conduct this process in other regions, which burdens the final cost of delinting. Aiming to offer an equipment with high capacity of delinting and at low cost, to meet small and medium producers of cotton from Northeast region, it has developed a delinting machine of cotton seed, chemical-mechanical and semi-automatic one with medium capacity of 750 kg hr-1. In this machine, it were tested cotton seeds with linter into exposure times (2, 3 and 4 minutes) whose results demonstrated that the exposure time to sulfuric acid for three minutes was sufficient for complete removal of lint, causing the seeds remain their high physiological quality. After delinting, we studied the effect of latent delinting of cotton seeds with sulfuric acid on the physiology quality through three storage methods: semi-cryogenic counter, nitrogen vapor and dry chamber. The physiological quality of seeds under freeze of - 40 º C and - 170 ° C and in a dry chamber for a storage period of 300 days was evaluated by two seeds defrosting techniques (room temperature and thermostatic bath), by considering that storage for 300 days after delinting and resgadless of the storage method and defrosting, the seeds physiological quality was not affected. We conclude, therefore, that there is no loss latent effect of the cotton seeds physiological quality BRS Araripe cultivar, due to chemical delinting.