EFFECT OF SEEDING RATES AND HERBICIDES ON LEAF AREA INDEX AND ACCUMULATION DRY MATTER IN RICE AT DIFFRENTE TIMES

Abstract

A field trial was carried out at Mishkab Rice Research Station, Al-Najaf Al-ashraff governorate during the summer seasons of 2008 and 2009 to investigate the effects of seeding rates (120,140,160 and 180 kg.ha-1) and herbicides (control, oxadiazon, propanil and weed-free) on leaf area index and accumulation dry matter of Yasamin rice cultivar. The design used was split plot by RCBD arrangement with four replicates. The results indicated that the seeding rate 180 kg.ha-1 was superior in giving the highest values of accumulation dry matter,706.3 , 1077.9, 1325.6 , 1614.2 704.8, 1012.6, 1425.6 and 1478.3g.m-2 in both seasons, respectively, these increases were due to the highest values of leaf area index 2.717, 4.332, 3.516, 3.146, 2.962, 4.715, 3.727and 3.024, respectively. For herbicide treatment weed free gave highest values for two seasons in accumulation dry matter, 723.8, 1094.8, 1353.3, 1628.7, 733.5, 1015.3, 1460.8 and 1511.8 g.m-2 respectively, because of increased of leaf area index 2.612, 4.677,4.185 , 3.306, 2.945, 4.441,4.441 and 3.108 in both seasons, respectively, as compared with other treatments, while was superior oxadiazon and propanil significantally in giving the highest values leaf area index and accumulation dry matter in both seasons compared with weedy treatment.