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Subject: Entomology × Author: KAU × Author: Sheela, M S × Start date: 1984 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Control of root-knot nematode (Meloidogyne incognita Kofoid and White, Chitwood) infesting black pepper (Piper nigrum L.) by bacterial pathogens
    (Department of Entomology, College of Horticulture, Vellanikkara, 1990) Sheela, M S; KAU; Venkitesan, T S
    A survey was carried out to study the occurrence and association of bacterial pathogens of the root-knot nematode Meloidogyne incognita infesting the black pepper (Piper nigrum L) covering ten major pepper growing districts namely Kannur, Eranakulam, Idukki, Kollam, Kottayam, Kozhikode, Pathanamthitta, Thiruvanandapuram, Thrissur and Waynad. The survey revealed that six species of bacteria were associated with the nematode namely, Bacillus subtilis.B. .pumilus, B. coagulans, B. macerans. B. circulans and E. licheniformis. B. subtilis, B . pumilus and B. licheniformis were found associated with egg masses, second stage juvenile and adult females while B. coagulans. B. macerans aud circulans were obtained from egg masses and adult females only. These six Bacillus spp. showed ovicidal and larvicidal effect against M. incognita. The pathogenic effect tested with the six Bacillus spp. on M. incognita on tomato as host plant showed that B. circulans (0.9x10^ cells per pot) and B._ macerans (0.8x10 cells per pot) compared with treatment of carbofuran 500 ppm were on par in reducing the larval stage of the nematode population in soil. However among the five species all were equal except B. subtilis (1.8x107 cells per pot) and carbofuran treatment in reducing the root-knot population in roots. Eight common host plants of root-knot nematode were tested for pathogenicity with the five Bacillus spp., B. subtilis (1.5x106 cells/ml), B. punilu3 (1.8x106 cells/ml) B. coagulans (1.2x10 cells per ml), B. macerans (0.8x10 cells per ml) and B. circulans (0.9x106 cells per ml). None of these plants showed any symptom of pathogenesis, withering or disease. Safety testing of these Bacillus spp. carried out by oral administration and subcutaneous injection, on two week old chicks, did not produce any bacterial infection indicating that itwas not injurious.