Effect of Defoliation and Fe and Mn Spraying on Quality and Quantity Characteristics of Sunflower (Helianthus annuus L.)

The study was aimed at identifying the amount of reduction in the negative effects of leaf removal on both quality and quantity of sunflower as a result of foliar application of Fe and Mn. Severe leaf removal reduced the seed yield and seed weight to 11% and 10.5% respectively. The use of Fe in comparison to control increased the seed yield and seed weight up to 12% and 10% respectively. The use of Mn in comparison to control caused an increase in seed number up to 11.6% but caused a reduction in seed weight to 10%. The use of Fe in normal foliar defoliation treatment (40% defoliation) caused a significant increase in seed yield but no significant effect was observed in sever defoliation treatment (80% defoliation). Although using Mn in all treatments led to a rise in seed yield, the effect was not significant, it could be concluded that the combined use of Mn and Fe had no significant influence on sunflower yield, so there might be an antagonistic effect between the two.