DESEMPENHO DE CULTIVARES E ÉPOCAS DE CORTE DE CAPIM ELEFANTE IRRIGADO EM CERES (GO)

Abstract

Elephant grass (Pennisetum purpureum Schum.) is a good alternative for forage production due to its high yield and quality if well managed. This study aimed to evaluate the growth, yield, and bromatological quality of elephant grass cultivars during the dry (under irrigation) and rainy season. This experiment was carried out at Instituto Federal Goiano (Goiano Federal Institute), Ceres Campus, Goiás State, Brazil, in randomized block design, split plots, and four replicates. The treatments consisted of six elephant grass cultivars and three cutting ages (45, 60, and 75 days). The cultivars were Common Shrimps, Purple Shrimps, BRS Capiaçu, BRS Canará, BRS Kurumi, and Napier. The characteristics evaluated were: (a) plant height (PH); (b) stem diameter (SD); (c) stem height (SH); (d) number of leaves (NL); (e) stem leaf ratio (S/L); (f) central leaf width (CLW); (g) number of aerial tillers (NAT); (h) number of basal tillers (NBT); (i) aerial tillering leaf area (ATLA); (j) basal tillering leaf area (BTLA); (k) clump diameter (CD); (l) green mass of basal tillers (GMBT); (m) pre-dried basal tiller mass (PDBTM); (n) green matter yield (GMY); (o) dry matter content (DMC); (p) dry matter yield (DMY); q) crude protein (CP); (r) fiber in acid detergent (FAD); (r) Fiber in neutral detergent (FND); (s) insoluble protein in acid detergent (IPAD); (t) insoluble protein in neutral detergent (IPND), (u) ethereal extract (EE); (v) ash content (AC);( (w) number of leafhopper nymphs (NN); (x) and plants attacked (PA) by leafhopper (Mahanarva liturata). Only the variables CD in dry season, NN, and AP in rainy season did not present significant differences among cultivars by Fischer test. Under this study conditions, BRS Capiaçu cultivar presents higher SD, leaf area, and lower leafhopper incidence. Napier cultivar presents higher SH, PH, yield, and lower FAD and IPAD. Kurumi cultivar showed higher S/L ratio and higher CP, lower FAD and FND. Increasing the cutting age decreases the nutritional quality of the cultivars in relation to CP, FAD, FND, IPAD, and FND, and showed lower scale for the BRS Kurumi cultivar. Under this study conditions, cutting management before sixty days contributes to a lower leafhopper occurrence during the rainy season.