(Gholizadeh et al, 2011) report that the spad reading at 55DAT varies more than spad reading at 80DAT. Furthermore, it can be explained that low SPAD reading variation at 80DAT indicated that it was almost homogeneous for entire study area while higher variation as can be seen at 55DAT indicated more heterogeneous. Spad value reduced at 25 and 45 DAT, then it quickly increased 2-3.5 unit of spad after application nitrogen fertilizer at panicle initation stage (40DAT) and increase significantly at (45 and 55DAT). Timing of N application can apply three or four times based on crop need and spad threshold and crop-growing condition at each location(fig 1&2). (Kumar et al, 2000) showed that the highest spad values were observed at the maximum tillering stage for all varites. It is necessary to mention, that starting with the first fertilization and until the last fertilization, highrt SPAD reading values were established in hybrid rice. Therefore, according to the data young rice before the tillering stage grows slowly chlororphyll content in leaves ,that in photosynthetic potential will be higher than in first fertilizer, by using the chlorophyll meter can synchronize fertilizer N application with actual crop demand. The liner relationship between leaf N content and to determine the plants need for additional N fertilizer (Swain and jagtap sandip, 2010).