Response of vegetative performance in soybean cultivars submitted to deficit irrigation

Resumo

Agricultural crops present phenological stages of less susceptibility to soil water deficit, in which the deficit irrigation management strategy can be used. In this context, the objective was to evaluate the influence of deficit irrigation management during different stages of development in three soybean cultivars in the edaphoclimatic conditions of the southern cerrado of Piauí. The research was conducted from September 2020 to January 2021, in the municipality of Uruçuí-PI (with geographic coordinates of 07º 13’ 46” S, 44º 33’ 22” W), under an experimental design of randomized blocks, in a split-plot scheme, where the treatments, composed in the plots, were defined according to the time of induction of the water deficit of 50% of the crop’s potential evapotranspiration - ETpc, via climate, in three soybean phenological stages (vegetative, flowering and production formation), and the subplots, were composed of three cultivars (FT 4191; FT 3181 and BG 478 IPRO), with three replications. In order to verify the effects of the imposed treatments, the following variables were evaluated: plant height, number of leaves and total dry mass of the aerial part. Variables were maintained for statistical analysis by Tukey’s test (cultivars) and Scott-Knott’s test (deficient irrigation treatments). The vegetative characteristics of the investigated soybean cultivars (plant height, number of leaves and shoot dry mass production) are drastically affected when the imposition of water deficit (50% of ETpc) is induced throughout the production cycle. Under such water conditions, the FT 4181 and 3191 IPRO cultivars stood out among the investigated cultivars, thus being identified as the most tolerant to reduced water availability in their different phenological stages.