EFFECT OF SOME AGRONOMIC PRACTICES ON YIELD AND ITS ATTRIBUTES OF SOME YELLOW MAIZE HYBRIDS

Two field experiments were carried out in an administration field at Sheet Al Hawa Village, Kafr Sakr district, Sharkia Governorate, Egypt, during the two successive summer seasons of 2013 and 2014 to find out the effect of four N levels (30, 60, 90 and 120 kg N/fad.) as well as three  phosphorus fertilization regimes (30 kg P₂O₅ fad., phosphorien and 15 kg P₂O₅/fad., with phosphorien) on yield potentiality of three yellow maize hybrids (SC 168, SC167 and TWC 352). The results could be summered as follows: In case of douple eared plants: Results revealed that the three maize hybrids gave significant differences in the majority of the studied characters of maize crop, since the SC 167 hybrid was superior in most yield attributes as it recorded high value in each of ear length, number of grains/row and hundred grain weight, followed by SC 168 and TWC 352 in descending order. Results of the combined analysis revealed that each N increment from 30 to 60 and 90 and then to 120 kg N/fad., significantly increased ear length, but this response was up to 90 kg N/fad., in each of number of grains/row and number of rows/ear, whereas hundred grain weight responded up to 30 kg N/fad., Addition of 15 kg P₂O₅/fad., with phosphorien gave high value in each of ear length, number of grains/row, number of rows/ear and hundred grain weight. In case of mono eared plans: The findings revealed that the three maize hybrids gave significant differences in the majority of the studied characters of maize crop, since the SC 167 hybrid was superior in most yield attributes and grain yield/ fad., followed by SC 168 as well as TWC 352. This superiority was expressed in ear length, number of grains/row, hundred grain weight, ear grain weight, while TWC 352 was superior in number of rows/ ear. Results of the combined analysis revealed that each nitrogen increment up to 90 kg N/fad., was accompanied by a significant increase in ear length, number of grains/row, whereas each of number of rows/ear and ear grain weight as well as grain yield/fad., responded up to 120 kg N/fad. In addition, the studied treatments showed that the application of 15 kg P₂O₅/fad., along with bio- fertilizer phosphorien gave the highest mean records in each of ear length, number of rows/row, hundred grain weight, ear grain weight whereas when maize plants were fertilized by 30 kg P₂O₅/fad., or phosphorien only gave higher grain yield/fad. The most interaction effect was observed between maize hybrids on one hand and each of N level and phosphorus treatments on the other hand. SC 167 had the highest grain yield averages under both 120 kg N/fad., and addition of phosphorien, whereas TWC 352 recorded the lowest grain yield under 30 kg N and phosphrien only.