Abstract
Root-knot nematodes (Meloidogyne spp.) are one of the most harmful plant pathogenic nematodes worldwide. Application of some herbal products can safely reduce negative effect of these nematodes. In the present study, the effect of aqueous extracts of Amygdalus scoparia and Arctium lappa on hatching and mortality of second-stage juveniles of M. javanica evaluated under laboratory condition and LC30, LC50, LC70 and LC90 values were determined by probit analysis from March to November 2016. Tomato seeds (cv. Early-Urbana) were sown in 1.5 kg plastic pots and simultaneously were inoculated with 4000 eggs and second stage juveniles (J2s) of M. javanica and soil-drenched (50 ml/pot) with selected concentrations of A. scoparia viz. 0.37, 0.54, 0.8 and 1.39% and A. lappa viz. 0.51, 0.85, 1.4 and 2.91%. The experiments were carried out in completely randomized design tests with four replications. Plant growth parameters as well as nematode population indices were calculated 60 days after inoculation. Results showed that after 120 hours, leaf extracts of A. scoparia at the rate of 7.5 and 10%, and leaf extract of A. lappa at the rate of 10% lead to 100% inhibition of M. javanica egg hatching under laboratory condition. Leaf extracts of both of the tested plants at the rate of 2% caused 100% mortality of J2s. Any increase in concentration of used plant extracts significantly improved the growth indices in both of the inoculated and uninoculated tomato plants. As compared to control, application of A. scoparia leaf extract at the rate of 2%, reduced the number of galls, egg masses and eggs per root system as well as the number of J2s per pot and reproduction factor of nematode by 37, 43, 45, 73 and 46%, and in the case of A. lappa, these indices reduced by15, 26, 27, 74 and 28%, respectively. Our results showed potential of leaf extracts of A. scoparia and A. lappa for management of M. javanica infecting tomato plants.
Acknowledgements
The authors thank for their valuable assistance.
Disclosure statement
No potential conflict of interest was reported by the authors.
Funding
The research was supported by Yasouj University, Yasouj, Iran.