Simmondsin as natural alternative fungicide in squash root rot disease

Abstract

Jojoba (Simmondsia chinensis) meal was extracted with acetone, isopropanol, boiling distilled water and methanol to obtain simmondsin. Simmondsin was tested against Squash root rot disease at four concentrations (10, 20, 30 and 40 mg/ml) using the radial mycelia growth under greenhouse and field conditions. Rhizoctonia solani (Kuhn) and Fusarium solani (Mart.) were isolated from naturally infected squash roots collected from different localities in Qalubia Governorate. Evaluation simmondsin extracts revealed that acetone was the most effective as it prevented the myceial growth of F. solani and R. solani at 40 mg/ml, followed by isopropanol, boiling water and methanol in vitro. All extracts even at concentration 10 mg/ml had little effect and failed to produce a considerable reduction in growth of the tested fungi. Squash Eskandrany seeds were treated with simmondsin extracts before sowing in artificially infested soil with F. solani and R. solani (pot experiments) or soil naturally infected (epidemic soil) by the tested pathogenic fungi (field experiments) resulted in significant reduction in both damping- off and dead plant (resulted from infection by root-rot disease) compared with untreated seeds. Also, both acetone and isopropanol extract were more efficient in reducing infection by damping-off and root-rot than boiling distilled water and methanol. While, squash seeds treated with tested simmondsin extract significantly increased fruit yield/plot compared with untreated seeds. Also, all tested simmondsin extracts significant increased plant survival.

Squash eskandrany seeds were treated with simmondsin extracts before sowing in artificially infested soil with F. solani and R. solani (pot experiments) or soil naturally infected (epidemic soil) by tested pathogenic fungi (field experience) resulted insignificant reduction in both damping- off and dead plant (resulted from infection by root-rot disease) compared with untreated seeds. Also, both Acetone and Isopropanol were more efficient reducing infection by damping-off and root-rot the high concentration 40 mg/ml than Boiling water and Methanol. On the other hand, squash seeds treated with tested simmondsin extract significantly increased fruit yield/plot compared with untreated seeds. Also, all tested simmondsin extracts significant increased plant survival.