Control of Root Lesion Nematode Pratylenchus spp. Infesting Potato Cv. Spunta Under Field Conditions Through Biotic Products.

In Egypt potato is the most popular solanaceous vegetables either for local consumption and exportation. Previous investigations showed that potato have been attacked by many plant parasitic nematodes. The root-lesion nematodes (Pratylenchus spp.) are economically the most important plant pathogens after root knot nematodes. They cause an average growth inhibition of 59.6% of infected potato seedlings with losses in tuber yields of 20-50% and in total plant weight of 50%.Producers have relied mainly on nematicides and chemical fertilizers to control plant parasitic nematodes and improved soil fertility, but their applications are associated with myriads of problems on human health and environment. Due to the consumer demand for chemicals-free food the main goal of this work is to evaluate the potentialities of some commercial bioproducts in controlling root lesion nematodes Pratylenchus spp. infecting potato cv. Spunta and improving yield production, under field conditions. The bioagents that have been assessed and their commercial name are Microbien containing the N2 fixing bacteria Pseudomonas spp. and Bacillus megatherium, Potassiumag containing the potassium solubilizing bacterium Bacillus circulanes and Phosphorine  contain the phosphorus solubilizing bacterium Bacillus megatherium ,Nemafree containing Serratia spp. ,theStanes Symbion VAM Plus containing the vascular arbiscular miccorhiza Glomus fasciculatum  and the Stanes Sting containing  the rhizobacteria Bacillus subtilis. A field experiment was conducted at Kafr-kandeel village, Giza governorate, Egyptto investigate the integration effects between these products to control Pratylenchus pp. and improve potato yield production cv. Spunta. The combined treatments are 1-Biofertilizers (Microbien, Phosphorine, Potassiumag) 2- Biofertilizers plus stanes Symbion,  3- Biofertilizers  plus Nemafree4- Biofertilizers, plus Stanes Sting 5- untreated plant using as control.  Obtained results after three months showed that all the tested combinations reduced Pratylenchus spp. both in soil and rootsby different rates, as well as increased potato yield production as compared to untreated control treatment. The highest increase in potato yield production 30% over control resulted from the application of the bionematicides Stanes Sting containing Bacillus subtilis in combination with the biofertilizers Microbien, Phosphorine and Potassiumag.