اثر برخی تیمارهای تغذیه‌ای رایج پسته بر فعالیت و میزان بیماری ناشی از نماتد ریشه گرهی در نهال های پسته

The Root knot nematodes are the most important plant nematodes with high economical plant parasites loss that possess a wide host range. Crop loss due to root knot nematodes has been reported widely from Iran and they cause a considerable loss on pistachio production in several provinces. The effect of different levels of macroelements including Nitrogen, Phosphorus, Potassium, and organic fertilizer (animal manure and vermicompost), humics and biological NPK on activity of the root knot nematode (Meloidogyne javanica) on white almond pistachio cultivars, was studied under greenhouse conditions. Considering soil analysis and the determination of optimal amount of the elements for pistachio, 16 g of Nitrogen, 20 g of Phosphorus and 22 g of Potassium were used. Also, 100 g of organic fertilizer (bovine), 50 g of vermicompost, 25 g of granular humic fertilizer and 4 g per liter of biological NPK were used. All of seedlings were same, each seedling was inoculated with a suspension containing approximately two thousand second stage juvenile and egg. After two months of inoculation, The effect of the treatments on some characters as stem length and internode length, fresh leaf and root weight were analysed. Besides, factors relating with the severity of disease caused by the nematode and the nematode population were determined. The biological fertilizer as well as organic fertilizers (bovine and vermicompost) showed a positive effect on plant growth characters. Seedlings that obtained the biological fertilizer possess lower gall numbers and fewer numbers of the nematode juveniles were observed in rhizosphere .