Evaluation of grain yield and yield components in intercropping of dwarf and tall cultivars of soybean (Glycine max L.)

To evaluate agronomic performance of two soybean cultivars in different planting patterns a field experiment was conducted with complete randomized block design with four replications at Agricultural Research Station of Qaemshahr in Mazandran province in 2008. Two cultivars (032; Nekador and Sari) in 50:5 planting ratio were row intercropped in different planting patterns including; one, two and three rows of each cultivar. Different intercropped planting patterns showed significant effect on grain yield and yield components. However planting patterns did not have significant effect on100 grain weight. Results indicated that the highest canopy height and pod number per plant were obtained from three and one row planting patterns, respectively. Calculation of LER revealed that the maximum intercropping efficiency (LER= 1.39) in one row planting pattern was higher than the sole crop stand. The evaluation of pod distribution in different part of main stem showed that higher grain yield of intercropped planting patterns was due to greater number of pods in upper part of the canopy. Comparison of actual: expected grain yield ratio indicated that the higher grain yield (%) in different planting patterns was obtained from 032 variety. In conclusion, the higher aggressivity of 032 over Sari was the main reason for its higher grain yield in different intercropped planting patterns.