Evidence of inhibitory effect of Pseudomonas fluorescens CHA0 and aqueous extracts on tomato plants infected with Meloidogyne javanica (Tylenchida: Heteroderidae)

Abstract

Abstract Effects of Pseudomonas fluorescens L. (jimsonweed) (Pf) isolate and the two plant extracts, Datura stramonium and Myrtus communis, were investigated on hatching and juvenile (J2s) mortality of Meloidogyne javanica (Tylenchida: Heteroderidae) under laboratory conditions. After determining the values of LC30, LC50, and LC70 of each extract, four leaf stage seedlings of tomato were treated by 20 ml of Pf suspension at a concentration of 108 CFU/ml, using a soil drenching method. After 1 week, the tested plants were inoculated by 4000 eggs and (J2s) of M. javanica and simultaneously were treated by 100 ml of the selected concentrations of D. stramonium (1.1, 1.4, and 1.8%) and M. communis (1.8, 3 and 5.2%), as soil drench. Results showed that a combination of Pf and the leaf extract, D. stramonium at the rate of 1.8% or M. communis at the rate of 5.2%, respectively, reduced the number of eggs per root system and the reproduction factor by 68 and 45%, the number of galls by 64 and 33%, and the number of egg masses by 65 and 43%, than the control. In conclusion, combination of Pf and D. stramonium at the rate of 1.8% or M. communis at the rate of 5.2% can significantly reduce the damage of M. javanica on tomato, under greenhouse conditions.

Keywords

• Pseudomonas fluorescens
• Plant extracts
• Meloidogyne javanica
• Biological control
• Tomato