Evapotranspiração, índice de área foliar e desenvolvimento radicular do arroz (Oryza sativa) sob irrigação.

Abstract

The evapotranspiration (ET) of rice and the evaporation of a class A tank (EV) showed significant correlation (r = 0.997) as well as the ET as compared with the leaf area index (LAI) (r = 0.930). On the other hand3 the EV medium coefficient (K) determined in order to estimate the water use by plants (ET = K . EV) was egual to 0.75583 while this same parameter3 when obtai ned from the LAI3 was 2.476365. The ET medium during crop vege tative3 reproductive and maturation stages was 3.87; 6.88 anã 4.39 mm/day3 respectively. The LAI variation during the crop ci cle was 0.28 to 3.55. The final distribution of roots in weight (g/m2/ depth), was 70; 16; 9 and 5% in the soil layers of 0-10; 10-20; 20-30 and 30-40 cm3 respectively. The initial and final stand was 276.5 shoots/m2, the height 70.7 cm and the production 4.695 kg/ ha.