Influence of Different Phosphorus Fertilization Levels and Sowing Date on Yield and Phosphorus Uptake by Corn

ent sowing dates (S1 = 21-9-1993 and S2 = 21-2-1994) on the total dry matter yield and its components (grain, ear and stover), grain protein contents, weight of 1000 grains, harvest index, shelling percentage and ear characters and com-ponents of corn plant (Giza 2 cultivar). The accumulation of phosphorus in soil was also investigated. Total dry matter yield and its components, 1000 grains weight, harvest index, shelling percentage, ear dry matter and volume, weight of grains/ear and phosphorus uptake were higher in sowing data S1 than sow-ing date S2. However, weight of cob/ear and number of rows/ear were higher in S1 and S2. The rest of characters and components were not affected by sow-ing date. Total dry matter yield and its components such as grains ears and sto-vers were significantly increased by the addition of 100 kg P2O5/ha. On the other hand phosphorus uptake by corn plant was significantly increased by the addition of 150 kg P2O5/ha. However, protein content of grain, the weight of 1000 grains, harvest index and shelling percentage were not affected by phos-phorus application rates. Total phosphorus content of soil increased with in-creasing phosphorus application rates