Thidiazuron and Ethyl-trinexapac Affect Upland Rice Irrigated by Sprinkler Irrigation

Rice is a prominent crop in Brazil. Its cultivation predominates in flooded areas in the South region of the country. However, the upland rice grown in the Midwest Region is a viable option for a sustainable expansion in the country. It still results in a grain yield lower than that of flooded cultivation, and there are constant problems with crop lodging, especially in areas using sprinkler irrigation. Thus, new ways to increase grain yield and minimize upland rice lodging are critical. The objective of this study is to verify the effects of thidiazuron and ethyl-trinexapac on the rice culture and verify whether the simultaneous use of both results in a beneficial interaction. The work was carried out in Selvíria, MS, using the cultivar BRS Esmeralda in the agricultural years 2015/16 and 2017/18. The experimental design was randomized blocks in a 2 × 4 factorial design with four replications. The treatments were combinations of application of the plant regulator thidiazuron at a fixed dose of 1.0 g ha-1 (presence or absence) and four doses of the growth regulator ethyl-trinexapac (0, 50, 100 and 150 g ha-1). Thidiazuron did not affect grains yield. Ethyl-trinexapac reduced plant height and eliminated lodging. The simultaneous use of both regulators did not affect the rice culture regarding the analyzed variables.