Evaluation of the Fungicidal and Insecticidal Activity of three Seed Oil Extracts against Some Phytopathogenic Fungi and Tomato Insects

This study was conducted to determine the antifungal and insecticidal activities of three seed extracts of jatropha nut, jojopa and castor oil. Seeds of jojoba, jatropha and castor bean were infected with fungi with an average of 52.70 %, 48.13 % and 84.43 % on PDA, rose bengal and malt extract agar media, respectively. Number of fungi was ranged between 8.3 and 216.7 cfu/100 seeds for jojoba, 188.3 and 350.0 cfu/100 seeds for jatropha and between 66.7 and 283.3 cfu/100 seeds for castor bean. Results detected a total of 13 species of fungi belonging to 6 genera were isolated and identified. A. niger (28.68 %) and Fusarium spp. (19.85 %) were the abundant common fungi associated with jojoba seeds and A. niger (41.49 %) was detected in jatropha seeds, while in castor oil seeds, the common associated fungi was A. niger (48.57 %). Ethanolic seed extracts of jojoba and jatropha were found to be effective against seed borne pathogenic fungi, while castor oil showed minimum activity. Moreover, the majority of the fungi were not sensitive to the water extract concentrations of 250 and 500 ppm unlike at higher concentrations of 1000 and 2000 ppm. The ethanolic extract of jojoba showed highest insecticidal activity against two insect of tomato, as the means number of eggs deposited /female were significantly decreased. When Tuta absoluta treated with seed extracts of all different treatment at concentrations, 0.5, 2, and 3 %, the eggs laid per female showed a significant decrease compared to control. The study also showed that the aqueous extract of castor bean was weaker in its effect on the Tuta absoluta insect compared to the other treatments. The ethanolic extract of jatropha showed highest activity on Phthorimaea operculella as the means number of eggs deposited /female were significantly decreased. Field application trails also indicated that water and ethanolic seed extracts of jojoba, jatropha and castor oil were more effective in increasing tomato yield in the two tested regions of Ismailia and Al-Gabal Alasfar.