STUDY OF SOME GROWTH CRITERIA AND YIELD OF SOYBEAN CROP WITH THE EFFECT OF BORON AND SOME GROWTH REGULATORS

The study was conducted at research station A, department of field crops, college of agricultural engineering sciences, university of Baghdad during summer 2021 to evaluate the effect of boron and some growth regulators on some growth criteria and yield of soybean crop (cv. shimaa). The experiment was carried out according to split plots by using randomized complete block design with three replications. The main plots included three concentrations of boron (75, 150 and 225) mg.L-1, the sub-plots included three levels of growth regulators, spraying kinetin (100 mg. L-1), spraying ethrel (200 mg.L-1) and spraying kinetin (100 mg.L-1) + spraying ethrel (200 mg.L-1) as well as spraying of distilled water as control treatment. The findings revealed that the spraying of ethrel at 200 mg.L-1 gave the lower means of plant height (114.68 cm), and gave the higher means of No. of branches (5.60 branch. plant-1), leaf area (97.86 dcm2), plant dry weight (206.64 g plant-1) and this led to give higher means of seed yield (2.715 ton. ha-1), while the concentrations of growth regulators did not significantly affect the leaf area index. Boron concentrations affected most of studied traits, 150 mg.L-1 of boron effect on most of traits and gave higher means of plant height (143.93cm), No. of branches (6.21 branch plant-1), leaf area (111.53 dcm2 plant), leaf area index (7.47), plant dry weight (246.45 g), this led to give higher means of seed yield (3.071 ton.ha-1). Result showed that boron and some growth regulators interaction have a significant effect on some characteristics under study. It has achieved spray treatments Boron with 150 mg.L-1 and ethrel of 200 mg.L-1 gave the higher means of No. of branches (6.97 branch plant-1), leaf area (114.26 dcm2.plant), LAI (7.62), plant dry weight (265.24 g.plant-1).