Effect of plant density ratios and weed control on the performance of maize-bean intercropping

Abstract

A 2-year study (2010-2011) was carried out in order to evaluate the effects of bean and maize intercropping. The experiment tested five different cropping systems: sole cropping of each crop, as well as intercropping of maize/bean with the ratios of 1:3 (M1B3), 2:2 (M2B2) and 3:1 (M3B1), each of which took place in the presence of two weed management systems (no weed control and weed eradication through manual removal), in a factorial experiment based on randomized complete block design using three replicates. Tests of homogeneity of variance for combined data over two years showed that data of both years could be analyzed together. The results showed that the effect of intercropping treatments on all measured traits in maize and bean were significantly different. A minimum land equivalent ratio (LER) for maize (0.78) was obtained for M3B1 under conditions of no weed control, while the highest LER (1.03) was observed in M3B1 under weed-free conditions. The highest (0.99) and lowest (0.70) LER values for beans were recorded for M1B3 under weed-free conditions and M3B1 under conditions of no weed control, respectively. M1B3 under weed-free conditions showed the highest total LER (2.02), while M3B1 under conditions of no weed control showed the lowest (1.48). Results of this study indicated that intercropping bean and maize can be an effective method to increase total productivity, and that the M1B3 system was the best cropping system for high productivity.