STUDIES OF YIELD POTENTIAL AND OIL CONTENT OF SOME PROMISING SUNFLOWER HYBRIDS UNDER LOW FERTILITY LEVELS

Abstract

Two field experiments were carried out at the Experimental farm, Faculty of Agriculture, Tanta University, at Kafr El-Sheikh, Egypt, during the two successive growing seasons 1998 and 1999 to study the response offour promising sunflower cultivars to low nitrogen fertilizater levels and phosphorine biofertilizer. Twenty four treatments, which were the combination among four sunflower cultivars (Vidoc, Euroflour, Alamo and Malabar), three nitrogen levels i.e. (15, 30 and 45 kg N/fed.) and two treatments ofphosporine (without phosphorine as control and with phosphorine). A split-split plot design with four replicates was used in this study. The main plots were assigned to sunflower cultivars, while sub plots were allocated to the three nitrogen levels. The two treatments of phosphorine • biofertilizer were randomly distributed in the sub­ sub plots. The important findings could be summarized as follows: 1- Sunflower cultivar had a significant effect on plant height at most growth stages, while nitrogen level had no significant . effect on plant height at all growth stages in both seasons. Application . of phosphorine biofertilizer significantly increased plant height at most growth stages in the two seasons.