DIFFERANTRAL RESPONSE OF SOME RICE CULTIVARS TO SEEDLING AGE AND PLANT SPACING AND THEIR EFFECT ON GROWTH TRAITS AND YIELD

Abstract

Two field experiments were carried out at Rice Research and Training Center, Sakha, Kafr El-Sheikh, in the summer seasons of 2019 and 2020 aiming to study the effect of three rice cultivars (Giza 178, Sakha107 and Sakha 108) to three seedling ages (20, 25 and 30 days after planting) and three transplanting spaces (15 × 20, 20× 20 and 25× 20 cm) as well as their interactions on growth characters, yield and its attributes. The results showed that cultivars significantly differed for all traits; Sakha 108 rice cultivar produced the maximum values for growth characters :leaf area index,crop growth rate ,relative growth rate and net assimilation rate as well as yield attributes :number of tillers/m², number of panicle/m², panicle length (cm), number of total grains/panicle, 1000 - grain weight (g) and grain yield (t/fed).While the lowest values of these traits were recorded by Giza 178 rice cultivar. Seedling age had a significant effect on all studied charactaristies. Younger seedlings (20 day old) produced significantly the highest mean values. While the minimum values of the previous traits were obtained when plants were transplanted at 25 day old seedlings.Plant spacing significantly affected on all traits. Wider spacing (25 × 20cm) gave maximum number of tillers/m², number of panicles/ m², panicle length (cm), number of grains/panicle, 1000 - grain weight (g) and grain yield (t/fed), while closer spacing (15 × 20 cm) gave the lowest values. A significant effect was found for the interaction between the three factors on the traits under study. The highest values of all traits were recorded when using Sakha 108 cultivar, youngest seedling age (20 day old) and widest spacing between hills (25 × 20 cm).On the other hand, the lowest mean values were recorded when using Giza 178 rice cultivar, the oldest seedling age (30 day old) and closest spacing between hills (15×20cm) in both seasons. In general, it could be recommended using Sakha108 rice cultivar with seedling age of 20 days and plant spacing of 25 × 20 cm under transplanting.