Efficacy of benzyladenine for compensating treduction in soybean productivity under low water supply

Abstract

Undoubtedly, drought is a negative consequence of climate change. Farmers have to deal with this issue and may be forced to irrigate their crops with less water than required, however reduction in productivity is anticipated. Thus, two–year field trials were conducted to assess the impact of irrigation regimes (60, 80 and 100% of crop evapotranspiration, denoted ET<inf>60</inf>, ET<inf>80</inf>, and ET<inf>100</inf>, respectively) and benzylad-enine rates (0, 50, 100, 150 and 200 mg L⁻¹, symbolized as BA<inf>0</inf>, BA<inf>50</inf>, BA<inf>100</inf>, BA<inf>150,</inf> BA<inf>200</inf>, respectively) on soybean. Findings clarified that the maximum increases in plant height and net assimilation rate were obtained with the interactions of ET<inf>100</inf> or ET<inf>80</inf> x BA<inf>200</inf> or BA<inf>150</inf> in both seasons. ET<inf>80</inf> x BA<inf>200</inf> (in both seasons) and ET<inf>100</inf> x BA<inf>150</inf> (in the first season) were as similar as ET<inf>100</inf> x BA<inf>200</inf> for enhancing pods number plant⁻¹. Irrigation water use efficiency progressively increased with decreasing irrigation water amount and increasing benzyladenine rate. In conclusion, the reduction in seed yield due to lowering water supply up to 80% of crop evapotranspiration (with saving 20% of irrigation water) could be compensated using benzyladenine, 150 mg L⁻¹, thus it should be involved in soybean irrigation programs.