Bromatological Composition of Elephant Grass Genotypes for Bioenergy Production

Aimed to evaluate the bromatological composition of different genotypes of elephant grass (Pennisetum purpureum Schum.) to energy production through combustion. The experimental design was a randomized block with 3 repetition and the treatments arranged in a subdivided plots scheme, considering as a plots the thirteen genotypes and harvests (dry and rainy) as subplots. The genotypes evaluated were Cubano Pinda, Porto Rico, Vrukwona, Piracicaba 241, Cuba 116, Taiwan A-25, Mecker, Napier, Canará, Guaçu, Cameroon, CNPGL 93-41-1 and CNPGL 91-25-1 clones. The experiment lasted two consecutive years with harvests made every 6 months, with a harvest in the dry season (September) and another one in the rainy season (March), totaling 4 harvests. For dry matter content analysis, three tillers were selected at random and dried in an oven at 55ºC until reaching a constant mass. For biomass quality analysis, the samples were ground in Willey type mills with 1 mm sieves, submitted to bromatological analysis to determine the neutral detergent fiber, acid detergent fiber, hemicellulose, volatile materials, and fixed carbon content. Higher levels of dry matter (greater than 44.4%), acid detergent fiber (greater than 44.8%), volatile matter (greater than 94.3%) and higher calorific value (greater than 3,450 kcal kg-1) occur in the dry period of the year and in genotypes Mercker, Piracicaba 241, Guaçu and BRS Canará genotypes.