Response of Some Soybean Cultivars to Low Light Intensity under Different Intercropping Patterns with Maize

摘要

A two-year study was carried out at Mallawi Agricultural Experiments and Research Station, A.R.C., El-Minia governorate, Egypt, during 2014 and 2015 seasons to determine the compatible soybean cultivar with high maize plant density to achieve farmer's benefit under intercropping conditions. Alternating ridges (70 cm width) between maize and soybean were used as 1:3, 2:4, 2:2, 3:3 and 4:2, respectively, in addition to sole culture of both crops. Local maize cultivar T.W.C. 310 was grown in one plant per hill distanced at 30 cm under intercropping and sole cultures, meanwhile local soybean cultivars (Giza 22, Giza 82 and Giza 111) were drilled in both sides of the ridge (two plants/hill distanced at 15 cm) under intercropping and sole cultures. A split plot distribution in randomized complete block design with three replications was used. The results indicated that maize yield attributes were increased significantly by decreasing maize plant density from 67 to 25% of sole maize under intercropping conditions, meanwhile the converse was true for plant height and grain yield per ha. All the studied maize traits were not affected by soybean cultivars. Also, all the studied maize traits were not affected the interaction between intercropping patterns and soybean cultivars. Soybean yield and its attributes were increased significantly by decreasing maize plant density from 67 to 25% of sole maize under intercropping conditions except plant height. The late-maturing soybean cultivar Giza 22 recorded the highest values of intercepted light intensity within soybean canopy, number of pods per plant, seed index, seed yields per plant and per ha, meanwhile, the highest values of biological yield per ha, plant height and number of branches per plant were recorded for soybean cultivar Giza 111. Soybean cultivar Giza 22 gave the highest seed yield per plant compared to the other cultivars under all the intercropping patterns. Relative yield of soybean showed that the early-maturing soybean cultivar Giza 82 is better adapted to low light intensity than the other cultivars. Land equivalent ratio and area time equivalent ratio values for intercrops were greater than 1.00 indicating less land requirements of intercropping patterns than sole maize. Growing four maize ridges alternating with two ridges of soybean cultivar Giza 82 achieved the highest net return compared to sole maize.