Effect of three sowing densities on sorghum bicolor development and performance in the tropics

Abstract

The objective of the study was to determine the productive response of sorghum forage (Sorghum bicolor L. Moench) grown at different sowing densities in Loma Bonita, Oaxaca, Mexico. A complete randomized experimental design was used where treatments: chorrillo, 125 000, 178 571 and 250 000 plants ha^-1 were tested under three repetitions, the experimental unit was 16 m². The growth variables in study were: plant height, stem diameter, chlorophyll content in leaves, leaf length, leaf width and foliar area per plant. At harvest, yield components were taken, forage yield (t ha^-1), plant weight, leaves and stems weight, panicle weight, number of spikelets and number of grains per spikelet. An analysis of variance was performed with GLM and mean comparisons were made in variables that were significant (Tukey, P ≤ 0.05). The results indicate that a chorrillo density generated a higher grain yield (4 420 kg ha^-1) and forage (27 157 kg ha^-1) above that obtained with the densities 125 000, 178 571 and 250 000 plants ha^-1. The ALP, DTA, AFO, CLO, LHO and AHO were influenced by the sowing density up to 42 DDS, after 56 and up to 80 DDS there were no effect to the densities tested. There were positive correlations between ALP with APA, DTA, LPA and REG (ranging from r = 0.63** to r = 0.95**). Grain yield was correlated with AFO (r = 0.74**) and PCG (r = 0.61**). Forage performance was positively correlated with six studied traits.