N.B. Izuogu, T.U. Olajide, E.K. Eifediyi and C.M. Olajide
Screenhouse and field trials were conducted at the University of Ilorin, Nigeria in 2013 and 2014 to investigate the effect of root knot nematode (Meloidogyne incognita) on the nodulation of five varieties of cowpea (IT89KD-288, IT82D-994, IT93K-452-1, T89K-391 and TT97 568-18). Half of the experimental plants were inoculated with Meloidogyne incognita eggs (n = 1500) while the remaining half served as uninoculated control plants. Data on growth and yield of cowpea, root gall, nodulation, and nematodes population densities in nodules were collected. Other parameters assessed included colour of dissected infected and uninfected nodules, texture of the nodules and varietal performance of the cowpeas. The results of both screenhouse and field trials were consistent in yield and visual observations of texture and colour. The yield of nematode-free varieties was significantly higher than that of M. incognita-infected ones. Infected nodules were dark brown in colour while the healthy ones were pink. For the field trials, nodulation counts in nematode inoculated plants were inversely proportional to the number of galls in their uninoculated counterparts in some varieties. Of all varieties, IT89KD-288 was most resistant to M. incognita. Due to high cost involved in the management of nematodes, especially with synthetic chemicals, variety IT89KD-288 is recommended for use in nematode endemic areas in Nigeria. Further study needs to be done on the histopathology of the infected and uninfected roots and nodules of these cowpea varieties.
N.B. Izuogu, A.R. Saliu, H.S. Baba and C.M. Olajide
Experiments were conducted at the teaching and research farm of Faculty of Agriculture, University of Ilorin, Nigeria to determine the effect of aqueous extract of Peperomia pelliucida and Terminalia catappa on the management of cyst nematode, Heterodera sacchari on some selected rice varieties. A screenhouse preliminary study was first carried out in December, 2014 to assess the pathogenicity of H. sacchari on ten varieties of rice from which five varieties were selected for field trials. The five selected rice varieties were grown on soil inoculated with cysts of H. sacchari. The field experiment was a 5×3 factorial type fitted into a randomized complete block design (RCBD). Soil nematode population, physiochemical soil analysis and phytochemical screening of the tests plants were carried out. Treatment application of aqueous leaf extract were conducted at the 2nd and 7th weeks after transplanting. Data were collected on the plant height, shoot, root weights, yield and soil nematode population. All numerical data were subjected to analysis of variance (Anova) using GENSTAT statistical package 12th edition and where significant differences were observed, means were separated using fisher’s protected LSD. Results from the study revealed that treatment combination of P. pellucida and T. catappa singly with FARO 60, FARO 61, and NERICA 8 performed significantly higher (p>0.05) than the other rice varieties for most of the growth and yield parameter measured. Significant differences occurred between shoot, root, and yield weight of treated plants and their control counterparts. There was no significant difference between the two plant extracts used with respect to parameters measured. Treated plants performed significantly higher than the control. Based on the results of the study, paddy farmers experiencing H. sacchari infestation are encouraged to treat the field with P. pellucida and or T. catappa, especially when planting FARO 60, FARO 61, and NERICA 8 as these combinations promise to give higher yield.
M.C. Olajide, N.B. Izuogu, R.A. Apalowo and H.S. Baba
This aim of the two-year study was to evaluate the nematicidal and antifungal activity of Moringa oleifera extracts against Meloidogyne incognita and fungi infestation in cucumber field. The aqueous extracts of leaves and seeds of M. oleifera were used to treat the plants. The findings of the present study revealed that the plant extracts were active against the test pathogens. All treated plants were significantly higher than the control with respect to number of leaves and branches, vine length, fruit weight, and yield. Of the two varieties of cucumber used, combination of cucumber market with moringa aqueous leaf extracts gave higher results. The phytochemical screening revealed the presence of alkaloids, flavonoids, glycosides, saponins, and tannins. These possess nematicidal and antifungal activities. Combination of variety 2, Market More with Moringa leaves aqueous extract is being recommended to farmers for management of nematode and fungal diseases. Organic amendments have the advantage of controlling environmental effluence.