EFFECT OF PLANTING AND WATER TERMINATION DATES ON PRODUCTIVITY AND GRAIN QUALITY OF GIZA 179 RICE CULTIVAR

Abstract

Planting dates and irrigation regimes are important aspects of successful rice production. In order to determine the effects of different planting and irrigation termination dates on productivity and some grain quality of Giza 179 rice cultivar, two sets of field experiments were initiated during 2016 and 2017 seasons at the Experimental Farm of Sakha Research Station, Kafr El-Sheikh, Egypt. Each experiment was laid out in a randomized complete block design (RCB), with four replications. In experiment (1), five planting dates were used (20th April, 1st May, 10th May, 20th May and 1st June). However, in experiment (2), six dates for terminating irrigation were used (terminating irrigation after complete heading, 5, 10, 15, 20 and 25 days after complete heading). The results of experiment (1) showed that early in planting date (20th April) took the longest duration to attain 50% heading, however, there was a decreasing in plant height when planting was delayed beyond 10th of May. Early (20th April) and mid (1st and 10th May) planting gave the highest values of number of panicles, panicle length, number of grains/panicle, panicle weight,1000 grain weight, grain and straw yields. However, late planting (20th May and 1st June) significantly reduced all previous traits, but gave the highest unfilled grains percentage. Grain length and shape as well as milling and head rice percentage gradually increased with delaying of planting date. Also, planting dates had significant effects on amylose content, but there was insignificant effect on gel consistency and gelatinization temperature. The results of experiment (2) indicated that plant height, number of panicles/m2and panicle length were not significantly influenced by dates of irrigation terminates. The grain yield and its attributes (number of grains/panicle, panicle grain weight and 1000- grain weight) were significantly increased with delay withholding irrigation compared with earlier cut-off dates of irrigation, which recorded the highest unfilled grains percentage. There were no significant differences among the last three treatments, in first season and between the last two treatments, in second season for grain yield. Withholding irrigation immediately at complete heading recorded the minimum values of grain length, width, milling recovery (hulling, milling and head rice %) and amylose content as compared with the other irrigation terminates . Finally, it could be concluded that, , a planting date of 1st and 10th May might enable to achieve high grain yield for Giza 179 rice cultivar . However, delayed planting up to 20th May achieve acceptable grain quality. Also, maximum grain yield and acceptable technological characters seem to be associated with delay in withholding of irrigation up to 20 days after complete heading.