YIELD AND CHEMICAL COMPOSITION OF FORAGE AND SILAGE OF NATIVE MAIZE UNDER IRRIGATED SEMI-ARID CONDITIONS

The preservation of native maize allows the selection of genotypes with forage potential in specific regions. The objective of the present study was to evaluate the yield and chemical composition of green forage and silage of 10 native and two commercial maize hybrids with forage potential, under semi-arid conditions with irrigation. Genotypes were grouped according to days to male flowering: early (80 days), intermediate (92 days) and late (111 days). Data were analyzed in a randomized complete block design with four replications (Tukey; alpha = 0.05). Intermediate and late maize had the greatest height, total dry matter yield (TDMY) and number of leaves (p < 0.05). Late genotypes showed higher values in cob yield and senescent matter (p < 0.05). The genotypes Olotillo x Tuxpeno and Tuxpeno II outperformed the hybrids 2038DK and P3966WP (3.50 and 9.24 Mg ha(-1), respectively) in TDMY (14.32 Mg ha(-1), on average). Olotillo x Tuxpeno and P3966WP presented similar crude protein values in green forage (81 g kg(-1); p > 0.05). However, when ensiled, the hybrid outperformed native corn by 22 % (92 vs. 75 g kg(-1); p < 0.05). Late-cycle native maize had the highest cob yields (4.59 Mg ha(-1)) and after ensiling, the ideal pH (< 3.9) and degrees Brix (8.5) values. The native genotypes Tuxpeno I, Olotillo x Raton, Olotillo x Tuxpeno and Tuxpeno II could be used in breeding programs to select materials with potential for forage production and conservation.