SUPPRESS OF SOYBEAN STEM FLY, Melanagromyza sojae (ZEHNT.) BY SPRAYING OF POTASSIUM, MICRONUTRIENTS AND THEIR COMBINATION AS FOLIAR APPLICATION ON FOUR SOYBEAN VARIETIES

The present study was carried out at the experimental farm of the Faculty of Agriculture, Benha University, Qalubiya governorate during two successive seasons; 2014 and 2015 to study the influence of potassium, micronutrients and their combinations as foliar application to suppress soybean stem fly, Melanagromyza sojae (Zehnt.) (Diptera: Agromyzidae) on four common soybean varieties. The obtained results showed that treatment of potassium silicate+micronutrients (Fe, Zn and Mn) (P1M^+) was the least injury for soybean stem fly through injury indicators which were the length of the tunnel and number of larvae inside the plant and there was no significant between varieties. The results also showed in relative increases of seed and stover yield when treated with potassium silicates + micronutrients; the seed yield was 25% and an average per two seasons was 0.30% compared to control. Results also showed an increase in total uptake of potassium with micronutrients for rest of the treatments; especially with potassium silicate that perhaps micronutrients enhanced the potassium absorption that allow the plant to build the restoration after M. sojae infection.