Investigation on the effect of some leaf fertilization products on the development, productivity and quality of sunflower. I. Morphology and productivity.

The investigation was carried out at the Dobrudzha Agricultural Institute – General Toshevo during 2010-2011. The effect of some fertilization products for leaf application (Amalgerol Premium, Foliar Extra, Hi-Phos, Bo-La and КТС) on the development and productivity of the San Luka and Yana sunflower hybrids was studied. Two check variants were used: one without fertilization and one with application of N60P120K80. San Luka and Yana were sown at a density 55 000 plants/ha. At budding stage the San Luka and Yana plants had the greatest plant height in the variants fertilized with N60P120K80 and treated with the leaf application products Foliar Extra and Hi-Phos. The highest seed yield from both hybrids during the years of investigation was obtained from the variant with conventional treatment followed by the variants treated with Foliar Extra, Hi-Phos, КТС, Bo-La and Amalgerol Premium. The head diameter in all variants treated with leaf fertilizers in both investigated hybrids was smaller than the diameter of the heads from the check variant treated with N60P120K80. Among the fertilizers for leaf application, Foliar Extra had the highest effect on the head diameter, followed by Hi-Phos. In comparison to the check treated with N60P120K80, there was no significant increase of the seed weight per head in any of the variants with leaf treatment.