THE IMPACT OF PHOSPHORUS FERTILIZER SOURCES AND RATES ON CANOLA PLANT (Brassica napus L.) GROWN IN CALCAREOUS SOIL

Two field experiments were carried out at El- Areish Agricultural Research Station, North Sinai Governorate during the two winter growing seasons of 2005/2006 and 2006/2007 to study the effect of canola varieties (Serw 4 and Bactol) with superphosphate and rock phosphate at rates (15.5 and 31 kg P₂O₅ /fed.) on some yield components, seed yield and chemical composition of canola plant grown in calcareous soil.
Results can be summarized as follows:
1-     Variety Serw 4 was significantly higher than Bactol one for plant height only in the first season. Also, the higher rate of P fertilizer in form of superphosphate was better than other treatments in the first season.
2-     Variety Serw 4 gave the highest significant value of seed weight/ plant (g) and oil yield (kg/fed.) in the first season, and oil yield (kg/fed.) in the second season compared to Bactol one. In addition, higher rate of P fertilizer for both P sources was better than lower one for seed weight/ plant (g), seed yield (kg/fed.) and protein % in the first season as well as seed yield (kg/fed.), oil yield (kg/fed.) and protein % in the second season. Variety Serw 4 received any of both P sources at higher level produced significantly better yield and its components than those recorded by other treatments.
3-     The treatment of superphosphate and rock phosphate at higher rate gave a significant increase in N- uptake of canola plants in comparison with the other fertilization treatments in both seasons.
4-     N- Uptake of variety Serw 4 fertilized with superphosphate at a rate of 31 kg P₂O₅/fed. was significantly higher than those obtained by others treatments.