Avaliação de linhas de arroz na tolerância à salinidade do solo

Abstract

The area of saline soils continues to increase due to inadequate irrigation and drainage practices. The effect of soil salinity on plants has been the subject of several studies, due to the stress that salinity causes on factors which limit rice growth and yield, as well as the quality of production. The purpose of this work was to evaluate the effect of soil salinity on the agronomic performance of rice (Oryza sativa L.) lines acquired in the Philippines. The variables measured were plant height, number of leaves per plant, number of tillers, number of sterile spikelets and no sterile per plant, dry matter of shoot and root, root/shoot ratio and yield of rice lines. The experiment was conducted in the Eduardo Mondlane Irrigation Scheme, Chókwé District, in the Subdivided Treatment Delineation (STD) and the treatments were arranged in a factorial (3*4), where the 3 levels of soil salinity - ECe (<1.0; -3.0 and > 3.0 deciSiemens per meter-dS/m) in 3 Philippine rice lines IR86384-58-2-1-B (L1), IR88358- B-AJY1-B (L2) and IR77664-BB-25-1- 2-1-3-12-5-AJY1 (L3) and a local Limpopo variety (V4) in 3 replicates. After the statistical analysis using the Fischer test at a significance level of 5%, all the variables measured in the L1 and L3 rice lines were negatively affected by the increase in salinity and presented mean yields of 5.5 tons per hectar. The L2 line was the most tolerant to soil salinity as it recorded the highest yield of all lines with 7.7 tons per hectar followed by the Limpopo variety with 6.8 tons per hectar for the ECe > 3.0 dS/m salinity conditions.