Study the influence of preceding crops and weed control treatments on nodules, weeds and soybean production

The present work was conducted at Shandaweel Research Station (Sohag Governorate, Egypt) Farm during 2017 and 2018 seasons to investigate the effects of preceding crop (wheat, clover, barley and faba bean) and weed control treatments (butralin at the rate of 2.5 l/fed (fed= 4200 m2), flauzifop-p-butyl at the rate of 1.5 l/fed + metribuzin at the rate of 300 cm3/fed, clethodim at the rate of 500 cm3/fed + metribuzin, hand hoeing twice at 30 and 45 days after sowing and untreated) on nodules, weeds and yield of soybean crop during 2017 and 20018 seasons. Using clover as preceding crop significantly decreased the dry weight of grassy, broad-leaved and total weeds (g/m2) compared to unweeded treatment and increased the number and weight of nodules in the both seasons. Also, it increased significantly plant height, number of branches, number and weight of pods/plant, seeds/pod and plant, seed index, seed yield (ton/fed) seed oil and protein % of soybean in the both seasons. Weed control treatments reduced the dry weight of grassy weeds, broad-leaved and total weeds compared with unweeded control in the both seasons. Amex, flauzifop-p-butyl and bentazon decreased the activity of nodules and weight of nodules in comparison with hand hoeing and unweeded treatments. Application of weed control treatments highly increase plant height, number of branches/plant, number and weight of pods/plant, seeds/pod, seed index, seed yield (ton/fed) seed oil and protein % of soybean crop and as well as seed yield (ton/fed) in the both seasons. The interaction between preceding crop and weed control treatments had a significant effect on the all studied traits in both seasons. Thus, dry weight weeds (g/m2), number and weight of nodules were decreased underplanting of soybean after clover and wheat compared with planting of soybean after barely and faba bean in 2017 and 2018 seasons. Fusilade super + Sencor, Select super + Sencor and hand hoeing twice gave the highest reduction on number and weight of nodules, dry weight of grassy, broad-leaved and total weeds (g/m2) underplanting of soybean after clover and wheat compared with planting of soybean after barely and faba bean and unweeded treatments in both seasons. Fusilade super + Sencor, Select super + Sencor and hand hoeing twice gave increased number and weight of pods/plant, weight of seeds/pod and plant, seed index, seed yield (ton/fed), seed oil % and protein % underplanting of soybean after clover and wheat compared with planting of soybean after barley and faba bean and unweeded treatments in the both seasons.