Beneficiamento de sementes de café e efeitos na qualidade fisiológica

ABSTRACTCOFFEE SEED PROCESSING AND EFFECTS ON PHYSIOLOGICAL SEED QUALITY The objective of this research was to obtain more suitable information concerning coffee seed processing inthe air-screen machines and gravity table, studying their effects on the physiological seed quality. One coffee seedlot of the Yellow Catuai IAC 62 cultivar was processed in a precleaner machine, in an air-screen cleaner and in agravity table, working in several sequences and combinations, according to technical recommendations for seedprocessing. The seeds were evaluated as to their physiological quality by the germination test, accelerated agingtest, seedling emergence, height and weight of dry matter of seedlings and young plants. The seed moisture wasdetermined at the beginning of the evaluations. The statistical design was randomized blocks with four replications.Mean comparisons were done by the Tukey test at 5 % of probability. It was concluded that: a) physiological seedquality was improved by specific equipments in the several phases of processing, with the best seed quality, obtainedwith complete operational sequence, where the lot was submitted to the action of the air-screen cleaner and gravitytable; b) the gravity table, associated with air-screen cleaner, was effective in removing debris from the seed lot,improving the physiological seed quality; c) larger or denser seeds had superior physiological performance thansmall sizeor lowdensity seeds, and the large pea berry seeds presented physiological quality similar to the largeflat seeds; d) discart of smallest or lightest seeds to improved the physiological seed quality, resulting in homogeneous,and high quality seed lots, and more vigorous young plants.Key words: Coffea arabica L., seeds, grading, germination, vigor.(