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Biotic and abiotic factors such as competition with weeds and water deficit may cause significant losses to soybean productivity. This study aimed at evaluating the effect of water deficit and plant recovery in the interaction between soybean (Glycine max) and slender amaranth (Amaranthus viridis) by using growth variables. A replacement series experiment was performed and treatments were arranged in a factorial scheme; they were composed of two water regimes (field capacity and water deficit (50% of field capacity)) and different soybean and slender amaranth proportions (100:0, 50:50 and 0:100%). Water regimes were applied 20 days after plant transplant. Height, leaf area and shoot dry matter were evaluated in soybean and slender amaranth under field capacity and water deficit, returning to normal irrigation conditions to evaluate the water recovery. Soybean exhibited competitiveness which was equivalent to the slender amaranth, independent of the water regime. Water deficit negatively influenced height, leaf area and shoot dry matter of soybean and slender amaranth. There was a reduction in leaf area and shoot dry matter of soybean after plant recovery caused by the irrigation deficit period. [ABSTRACT FROM AUTHOR]

The incidence of volunteer Enlist™ soybean in the post-emergence of crops in succession, such as wheat, requires changes in chemical control. Thus, the objective of the work is to evaluate the efficiency of different post-emergence herbicides in the control of volunteer Enlist™ soybean and wild radish and their selectivity to wheat. For this, four experiments were conducted in 2017 and 2018 in field and greenhouse. The treatments tested were pyroxsulam, saflufenacil, pyroxsulam + saflufenacil, pyroxsulam + bentazon, pyroxsulam + metribuzin, saflufenacil + bentazon, and saflufenacil + metribuzin in 2017, and triclopyr, saflufenacil, MCPA, quinclorac, dicamba, pyroxsulam + metribuzin, metribuzin + metsulfuron, pyroxsulam + bentazon and bentazon + metsulfuron in 2018. The variables were the control of wild radish and volunteer Enlist™ soybean phytotoxicity to wheat crop, yield components, and yield total. The association of the herbicides pyroxsulam and saflufenacil is efficient in the management of volunteer soybean EnlistTM, showing selectivity to wheat. The isolated application of dicamba and the associations of pyroxsulam with metribuzin and metribuzin with metsulfuron represent alternatives for selective management of volunteer Enlist™ soybean in wheat, in addition to efficiently controlling wild radish in post-emergence. [ABSTRACT FROM AUTHOR]