Crescimento, desenvolvimento e produtividade do gergelim sob reposição hídrica em Alagoas.

Abstract

ABSTRACT

The cultivation of sesame has economic potential in the Brazilian internal and external market, due to the production of excellent quality oil. However, the crop is sensitive to stress, excess or deficit of water, and the Northeast region of Brazil has irregular rainfall, which makes management difficult and reduces crop growth and productivity. Irrigation emerges as an alternative to work around stress due to water deficit. Thus, the objective of this work was to evaluate the growth, development and productivity of sesame as a function of water remuneration in the Coastal Tablelands of Alagoas. For this, an experiment was carried out and evaluated in the Laboratory of Irrigation and Agrometeorology (LIA) of the Federal University of Alagoas (UFAL), with four replications, in a randomized block arrangement with five treatments, 50, 75, 100, 125 and 150% of crop evapotranspiration. The sigmoidal, logistic and peak log normal models were fitted for growth variables, total dry phytomass of the shoot (FMSTA, kg ha-1), plant height (AP, cm) and leaf area index (LAI ), respectively, as a function of the accumulated degree days (°C day). For grain production (kg ha-1), adjust the second degree polynomial model as a function of the total irrigation depth applied to obtain the productivity and depth of maximum physical and economic efficiency. The maximum FMSTA (16,678.79 kg ha-1), maximum AP (256.25 cm), maximum LAI (11.37) and maximum grain yield (3,107.27 kg ha-1) were obtained in the irrigated treatment with 100 % of your water requirement. The growth models had trials of trials adjusted above 0.975; 0.957 and 0.909% for the sigmoidal, logistic and peak log normal models, respectively. The second-degree polynomial showed maximum physical (2,777.44 kg ha- 1) efficiency PG for irrigation depths of 419.89. Thus, sesame is resistant to drought and presents reduced growth and productivity when under stress due to water deficit. Returning 100% of ETc is the most adequate to achieve higher growth and productivity. Empirical models accurately simulate sesame growth.

Keywords: Sesamum indicum L.; Modeling; Irrigation