Two field experiments were carried out at the Experimental Farm of the Rice Research and Training Center (RRTC), Sakha, Kafrelshiekh, Egypt, during 2012 and 2013 rice seasons; the study to identify the optimum time for Nitrogen, Potassium fertilizer growing application and foliar of ascobien compound application on growth and yield characters to increase the productivity of hybrid rice seed. The study included that two parental lines the first was IR69625 A as female line, with abortive sterility and the second was Giza178 cultivar as restorer line to produce F₁ hybrid seed. The experimental design was A split – split plot design with three replications. The obtained results could be summarized as follows: Increasing the number of nitrogen fertilizer application time, especially when it applied at booting stage, resulted in a significant increase in heading date, plant height, flag leaf angel, flag leaf area, number of tillers hill^-1, number of panicle hill^-1, panicle length, panicle weight, number of filled grains panicle^-1, seed set%, 1000- grain weight, grain yield and harvest index% in both seasons. The highest seed yield was obtained when nitrogen fertilizer was adding in four equal doses in both seasons. The highest seed yield was obtained when potassium fertilizer was applied in two equal doses as basal soil and especially when it added at Panicle initiation stage (SI). Application of K- fertilizer at the two equal doses (SI) resulted in a significant increase in number of panicle hill^-1, panicle exertion, panicle length, panicle weight, number of filled grains panicle^-1, seed set %, 1000- grain weight, grain yield, harvest index % in both seasons. The foliar application of ascobien compound at 25 and 45 days after transplanting recorded that the highest and significant values of heading date, plant height, flag leaf angel, flag leaf area, number of tillers hill^-1, number of panicle hill^-1, panicle exertion, panicle length, panicle weight, number of filled grains panicle^-1, seed set %, 1000- grain weight, grain yield and harvest index % compared with other applications in both seasons. The all interaction between and among the three factors under study showed a significant effect on a lot of characters especially in the grain yield in the two seasons of study. From this study, it can be concluded that application of nitrogen on four equal doses (STIB), potassium in two equal doses (SI) and foliar application of ascobien at 25 and 45 days after transplanting could be recommended for optimum productivity of hybrid rice seed (SK 2034 H).