Seed size affects productive parameters in Sudan grass

ABSTRACT: The use of larger seeds may improve the initial development, plant stand, and mass productivity in forage crops. The present study aimed to evaluate the effect of the size of seeds of Sudan grass (Sorghum sudanense L.), standardized on density, on parameters of physiological quality and crop productivity. Seeds were processed in a gravitational table in order to become uniform in terms of density and then submitted to sieves with apertures of 1.75 or 2.00 mm. Three different treatments (seeds without size classification, seeds with diameter between 1.75 mm and 1.99 mm, and seeds with diameter above 2.00 mm) were compared. This study consisted of a laboratory stage for the analysis of physiological variables of seed, and a stage in field plots under a randomized block design and 3 replicates. Larger seeds presented better physiological and productive performance and had a higher germination rate, seedling growth, and forage yield at the first cut. Both the sieve with opening of 1.75 mm and that of 2 mm were suitable for processing of seeds of this species.