Sunflower performance according to water suppression management

Abstract

Sunflower (Helianthus annuus L.) stands out as the oilseed crop with the largest expansion in the world. Thus, the objective of this study was to evaluate the most appropriate moment to suppress irrigation, without hampering the productive and quality aspects of sunflower culture. The experimental design used was the randomized blocks, with six treatments and four replicates, where the treatments were as follows: irrigation up to 45, 52, 59, 66, 73 and 80 days after sowing. At 90 days after sowing, the following variables were analyzed: mass of 1000 seeds, productivity, dry mass of the chapter and stem, oil content of the seed and water use efficiency in the production of seed and oil. For the 1000 seed mass variable, a significant effect (p <0.05) was observed, in which the linear model stood out with the highest R². Sunflower productivity was noticeable, its increase relative to 10 days of suppression, obtaining 2,370.30 kg ha^-1. From the results obtained in the experiment, it was possible to conclude that, when irrigation suppression occurs at any stage of the sunflower cycle, all components of crop production tend to be inhibited. The crop has the maximum water use efficiency at irrigation suppression on day 45 after sowing, therefore, contributing to a lower water consumption.