Estabilidade e adaptabilidade de clones de pennisetum sp. Sob pastejo. Mancha ocular

The work was conducted at the Experimental Station of Itambé, of the Pernambuco State Agricultural Research Enterprise, to evaluate the adaptability and stability of Pennisetum sp. clones under pasture and Helminthosporium sp. incidence. The experimental design was randomized blocks, with 5 replicates and 16 treatments. Plots measured 5x5 m with one meter between rows spacing. Helminthosporium sp. incidence was studied by note scale according to spot presence on the leaves of the studied genotypes. With regards to genotype adaptability, Mineirão (0.31), Taiwan A 25 P 18 (0.50), SEA P 36 (0.28), SEA P 37 (0.38) and Gigante de Pinda P 73 (0.46) had regression coefficients below population average (β 1i ), indicating unfavorable environment adaptability. Genotypes Pusa Napier 1 P 25 (1.58), Pusa Napier 1 P 27 (1.55), Pusa Napier 1 P 28 (1.47), Pusa Napier 1 P 32 (1.28), Pusa Napier 1 P 33 (1.22), SEA P 35 (1.60), HV 241 (1.41) and Pioneiro (1.36) had better response in favorable environments, and Pusa Napier 1 P 31 and Roxo de Botucatu P 80 had ample adaptability. Hybrid HV 241 and Pioneiro had significant deviations from regression by the F test (p