Studies on the use of seeds of some indigenous plants for the control of root-knot nematodes.

Abstract

Meloidogyne javanica (Trueb) Chitwood Root knot nematodes invade the roots of plants and cause significant harm to crops. Fifty plant seeds belonging to different families were collected and evaluated for their nematicidal activity. Seeds were screened for nematicidal activity in vitro and in vivo. Aqueous seeds extract of Acacia concinna, Amaranthus paniculatus, Anethum graveolens, Cassia fistula, Cassia holosericea, Leucaena leucocephala, livistona chinensis, Moringa oleifera, Nigella sativa, Sesbania bispinosa and Canna indica showed hundred percent decrease in egg hatching of Meloidogyne javanica. Aqueous seeds extract of Acacia stenophylla, Asteracantha longifolia, Brassica juncea, Caesalpinia pulcherrima, Clitoria ternatea, Conocarpus lancifolius, Cuminum cyminum, Foeniculum vulgare, Papaver somniferum, Peltophorum pterocarpum, Sesbania bispinosa, Solanum miniatum and Trigonella foenum-graecum showed 100 percent juvenile mortality in vitro. Methanolic seeds extract of Leucaena leucocephala, Cassia fistula, Peltophorum pterocarpum, Canna indica, Brassica juncea, Cassia holosericea, Acacia concinna, Caesalpinia pulcherrima, Linum usitatissimum and Thespesia populnea also showed significant reduction in egg hatching and larval mortality of Meloidogyne javanica in vitro In green house experiment against Meloidogyne javanica aqueous extracts of seeds powder were found to be effective either by drenching or seed treatment were Sesbania bispinosa, Solanum nigrum, Clitoria ternatea, Brassica juncea, Acacia stenophylla, Foeniculum vulgare, , Canna indica, Cuminum cyminum, Ricinus communis, Trigonella foenum-graecum, Pithecellobium dulce, Linum usitatissimum, Moringa oleifera, Anethum graveolens, Asteracantha longifolia, Trachyspermum ammi, Canna indica, Livistona chinensis, Clitoria ternatea, Pithecellobium dulce Thespesia populnea and Coriandrum sativum. Organic amendment of soil was done by mixing seed powder in soil @ 1 % w/w after 3 weeks of organic amendment seeds were sown. Amendment with seeds powder of Asteracantha longifolia, Amaranthus paniculatus, Caesalpinia gilliesii, Ricinus communis, Sesbania bispinosa, Parkinsonia aculeata, Tamarindus indica, Eruca sativa, Acacia stenophylla, Albizia lebbeck, Nigella sativa, Piper nigrum, Ipomoea pes-caprae, Brassica juncea, Prunus avium, Solanum nigrum, Foeniculum vulgare, Thespesia populnea, Sapindus trifoliatus, Cordia sebestena, Moringa oleifera, Tribulus terrestris, Clitoria ternatea, Cassia holosericea, Senna alata, Peltophorum pterocarpum, Delonix regia, Coriandrum sativum, Linum usitatissimum, Adenanthera pavonina, Leucaena leucocephala, pithecellobium dulce, Roystonea regia, Datura innoxia, Conocarpus lancifolius, Anethum graveolens, Trigonella foenum-graecum, Trachyspermum ammi, Eragrostis abyssinica, Cuminum cyminum, Sinapis alba, Caesalpinia pulcherrima, Pongamia pinnata, Cassia fistula Acacia concinna and Acacia nilotia appeared to be potent against root knot nematode and increased the growth of okra and cowpea plants. When organic amendment of soil with Acacia concinna, Canna indica, Foeniculum vulgare, Sesbania bispinosa and Solanum nigrum seeds meals at different concentrations of 0.3, 0.5 and 1% w/w of soil was performed. Most significant results were obtained in the treatments with Sesbania bispinosa and Solanum miniatum at organic amendment of 1 percent w/w in soil in both crops. This concentration was selected for further studies and field experiment. Combined use of Sesbania bispinosa and Solanum nigrum seed meals with chemical and biological antagonist also provided significant results as there enhancement in growth parameters and significant decrease in infection of Meloidogyne javanica and knot count in roots. Most promising results appeared when seed meals were mixed with Beauveria bassiana and Furadan. Preliminary phytochemical screening from ethanolic extract of seeds with strong nematicidal activity was performed. Phytochemical tests revealed presence many secondary metabolites flavanoid, terpenoid, steroid, tannin, carbohydrate, phenol, alkaloid, saponin, coumarin, glycolside and phlobatannin in seeds. Organic amendment of soil in field condition with Solanum nigrum and Sesbania bispinsosa showed significant decrease in the infection of root knot nematodes and increase in okra and cowpea plants growth.