Effect of Time and Methods of Nitrogen and Potassium Application at Different Growth Stages on Hybrid 1 and Giza 178 Rice Cultivare.

TWO FIELD experiments were carried out at the experimental farm of Rice Research & Training Centre, Sakha, Kafrelsheikh, Egypt to study the effect of nitrogen and potassium fertilization on growth characters, yield and its components of Hybrid rice1 and Giza 178 rice cultivar. The experimental design was a split-split plot design with four replicates, the main plots were assigned to rice cultivar, methods of nitrogen application treatments which were randomly distributed in sub plots as N1 1/2 basal +1/4 at Mid Tillering (MT) +1/4 at Late Boating (LB) and N2 (1/2 basal +1/4 at Mid Tillering + 2% sprayed at (LB) time and methods of potassium application were arranged in the sub-sub plot and assigned as (K1) 1/2 basal +1/2 as topdressing (TD) at L.B, (K2) 1/2 basal+1/4 TD at PI+1/4 TD at L.B, (K3) 1/2 basal +2 % foliar at PI +1/4 TD at LB, (K4) 1/2 basal+1/4 TD at PI+ 2% foliar at LB, (K5) 1/2 basal + 2 %foliar at PI + 2 % foliar at LB.
The obtained results could be summarized as follows: In both seasons, the data showed that Hybrid rice1 recorded the highest values of the number of tiller/m2, the number of panicle/m2, the number of filled grain/panicle, 1000 grain weight, straw yield and grain yield compared with Giza 178 rice cultivar. Giza 178 recorded significantincrease in the flag leaf area, total chlorophyll content. Times and methods of nitrogen application as N2 caused significant increase in the flag leaf area and total chlorophyll content in both seasons and straw yield in the second season only, while N1 treatment gave significant increase in number of tillers /hill and number of panicles /hill in both seasons, while number of filled grains /panicle, grain yield (ton/fed) in 2008 season, Times and methods of potassium application caused significant effect in both seasons on plant height, total chlorophyll content, Number of filled grains. panicle-1, 1000- grain weight, grain and straw yields ton/fed-1.
We can concluded that Hybride1 rice cultivar when treated with nitrogen as 1/2 of the dose as basal +1/4 at MT +1/4 at late boating stage (LB) and potassium application either as1/2 dose as basal +1/4 as foliar at PI (2% of K2O) +1/4 as TD at LB stage or as1/2 dose as basal +1/4 as TD at PI+ 1/4 as foliar at LB stage (2%of K2O) achieved the highest values of most studied characters and grain yield ton.fed-1.