Asra Salari

Greenhouse and laboratory studies were conducted to test the efficacy of walnut aqueous extract against Meloidogyne javanicaon tomato plant. Aqueous extract of walnut leaves were prepared with various concentrations rang (5%, 10% and 20%) that they were diluted from stock solution and water were used as control. Tomato seedling roots were soaked for one hour in the mentioned concentrations, then tomato plants were transplanted to the pots and 20 cc of walnut extract injected to the soil. One day later, second stag juveniles (J2s) of nematode were incubated around the tomato roots. According to the results, after 57 days, increasing in the concentrations of aqueous extract (20%) caused a significant reduction in final population of nematode and reproduction factor, but there was a reduction in root length and stem length of tomato with 20% concentration, as compare to control. However an increase in dry weight of roots and stem were observed. In laboratory test, to assess the nemtocidal effect of these extracts, J2s were exposed to the mentioned extracts for 24, 48 and 72 hours. The mortality of J2s, were affected by percentage of extract concentrations and time in petri dish environment. In case of any increase in concentration and time, there was a significant increase in mortality of nematodes. Totally the results showed the aqueous extracts of walnut leaf have nematocidal efficiency