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19891
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Subject: Agricultural Entomology × Author: Anitha, N × End date: 1989 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Effect of root-knot nematode meloidogyne incognita (Kofoid and White) chitwood and reniform nematode rotylenchulus reniformis linford and oliveria on cowpea
    (Department of Agricultural Entomology, College of Agriculture, Vellayani, 1989) Anitha, N; KAU; Anitha N Researcher
    Three pot culture experiments were laid out with the objectives (i) to study the effect of M. incognita on cowpea, (ii) to study the effect of R. reniformis on cowpea and (iii) to study their combind effect. The individual effects were assessed with nine population levels ranging from 0 – 1000 larvae/100 ml soil each replicated thrice. In the combined experiment three population levels, 100, 200 and 400 and their three combinations were tried each replicated four times. The results indicated that at initial inoculam levels of 100, 200, 400 and 600 larvae/ 100 ml of soil of the two nematodes, M. incognita and R. reniformis extered severe damaging influence on cowpea. The higher inoculum levels of 800 and 1000 larvae/100 ml soil did not show a progressive increase in crop loss. It is evident that the threshold levels of the nematodes will fall within the range of 100 to 600 larvae/100 ml soil. In the combined inoculation of the nematodes, an inoculum level of 400 M. incognita followed by 400 R. reniformis/100 ml soil 15 days later exerted a highly deleterious effect on cowpea. Simultaneous inoculation did not lag for behind in its debilitating effect. Considering the nematode population in soil, multiplication rate of both nematodes were found higher in lower inoculum levels than in the higher inoculum levels. In the combined inoculation, reniform nematode dominated root - knot nematode. Reniform nematode had an adverse effect on the multiplication of root-knot nematode. Both nematodes thrived well when M. incognita was inoculated prior to R. reniformis.