Effects of some micronutrients and macronutrients on the rootknot nematode, Meloidogyne incognita, in greenhouse cucumber (Cucumis sativus cv. Negin)

Abstract: The effects of some micronutrients (iron, zinc and silicon) and macronutrients (nitrogen, phosphorus and potassium) were evaluated on the root-knot nematode, Meloidogyne incognita and plant growth parameters of cucumber (Cucumis sativus cv. Negin) in two independent trials. Each of iron, zinc and silicon micronutrients was used at 5 mg/kg of soil, as iron sequestrene (Fe-EDDHA), zinc sulfate (ZnSO_4) and sodium siliconate (Na_2O_3Si), respectively. Furthermore, nitrogen at 60, 120 and 180 mg/kg, phosphorus at 25, 50 and 75 mg/kg and potassium at 12.5, 25 and 37.5 mg/kg of soil were used as urea, triple superphosphate and potassium sulfate, respectively. At four-leaf stage seedlings, 8000 nematode eggs and juveniles (2 egg and juveniles/gr soil) were added around the roots. After 60-days, data analysis indicated silicon + iron, significantly reduced the number of galls/g of root by 55 and 42% compared to control, in the two experiments, respectively, but none of these treatments resulted in significant positive effects on the growth or yield of the studied cucumber cultivar. When macronutrients were evaluated, results showed that N_120P_25K_25 (120 mg/kg of Nitrogen, 25 mg/kg of phosphorus and 25 mg/kg of potassium) and N_120P_50K_25 (120 mg/kg of nitrogen, 50 mg/kg of phosphorus and 25 mg/kg of potassium) significantly reduced the number of galls by 96 and 81% (experiment 3) and 79 and 70% (experiment 4) when compared with control, respectively. These both treatments also improved cucumber growth parameters such as shoot dry and fresh weights, root fresh weight and fruit yield.