Evaluation of Plant Materials as Root- Knot Nematode (Meloidogyne incognita) Suppressant in Okra (Abelmuscous esculentus)

Plant parasitic nematodes are one of the most important pests on agricultural fields; they cause serious damage to crops. Synthetic pesticides have been used lately to combat the menace of nematodes. Pesticide residues have however been detected in fruits and vegetables due to the residual effect of nematicides in the environment. To minimize the negative effect of synthetic nematicides, it is important to search for alternative plant protection methods. In this study, plant materials (Euphorbia heterophylla, Hyptis suaveolens, Eucalyptus officinalis, Ocimum gratismum and Crotolaria juncea) were investigated as soil amendments for possible reduction of root-knot nematode (Meloidogyne incognita) populations on okra (Abelmuscous esculentus). Results revealed that the highest rate of amendment with E. officinalis reduced significantly (p<0.05) the number of root galls, egg masses and juveniles, with a simultaneous increase in okra yield. Thus soil amendments with E. officinalis could be an alternative to synthetic nematicide in M. incognita management

Efficacy of Agricultural Wastes in the Control of Rice Cyst Nematode (Heterodera sacchari)

Rice cultivation is endangered by plant parasitic nematodes. Rice cyst nematode (Heterodera sacchari Luc & Merni, 1963) is one of the nematode pests which affect the quantity and quality of rice. The use of synthetic nematicide has reduced considerably yield losses incurred by H. sacchari infestation; this achievement is associated with environmental damage and occurrence of pesticide residue in food. In an effort to redeem the environment, development of alternatives to conventional nematicide is imperative. Agricultural wastes are renewable source of bio-pesticides if properly processed. The objectives of this research were: to hydrolyze pentoses and convert it to furfural in agricultural wastes; to determine the amount of furfural in 100, 150 and 200 g of agricultural waste; to incorporate the agricultural waste material into the soil as soil amendment; to determine how much furfural was released in the process of acidic/enzymatic hydrolysis of the biomaterial, and to determine the nematicidal effect of furfural in control of rice cyst nematode. Corn cobs (CNCB), rice husks (RCEH) and sorghum husks (SGMH) were digested for furfural production in place of synthetic nematicide carbofuran (CBFN) options in the management of rice cyst nematode. The quantity of furfural in 100, 150 and 200 g of each waste was determined, and the agricultural wastes were applied as soil admixes. The sorghum husk (SGMH) produced the highest furfural amount (0.796). At quantity of 200 g SGMH was significantly (p=0.05) better than all other treatments on plant height, number of tillers and rice yield. There was no significant difference of the effect of rate of application (level) on final cyst count in soil and root. Agricultural wastes, especially sorghum husks, can serve as an alternative to the use of synthetic nematicide. Residual furfural was absent in the agricultural waste after harvest. Furfural is quickly broken down by soil microorganisms under aerobic conditions; hence, it is not toxic to the environment

Efficacy of Agricultural Wastes in the Control of Rice Cyst Nematode (Heterodera sacchari)

Rice cultivation is endangered by plant parasitic nematodes. Rice cyst nematode (Heterodera sacchari Luc & Merni, 1963) is one of the nematode pests which affect the quantity and quality of rice. The use of synthetic nematicide has reduced considerably yield losses incurred by H. sacchari infestation; this achievement is associated with environmental damage and occurrence of pesticide residue in food. In an effort to redeem the environment, development of alternatives to conventional nematicide is imperative. Agricultural wastes are renewable source of bio-pesticides if properly processed. The objectives of this research were: to hydrolyze pentoses and convert it to furfural in agricultural wastes; to determine the amount of furfural in 100, 150 and 200 g of agricultural waste; to incorporate the agricultural waste material into the soil as soil amendment; to determine how much furfural was released in the process of acidic/enzymatic hydrolysis of the biomaterial, and to determine the nematicidal effect of furfural in control of rice cyst nematode. Corn cobs (CNCB), rice husks (RCEH) and sorghum husks (SGMH) were digested for furfural production in place of synthetic nematicide carbofuran (CBFN) options in the management of rice cyst nematode. The quantity of furfural in 100, 150 and 200 g of each waste was determined, and the agricultural wastes were applied as soil admixes. The sorghum husk (SGMH) produced the highest furfural amount (0.796). At quantity of 200 g SGMH was significantly (p=0.05) better than all other treatments on plant height, number of tillers and rice yield. There was no significant difference of the effect of rate of application (level) on final cyst count in soil and root. Agricultural wastes, especially sorghum husks, can serve as an alternative to the use of synthetic nematicide. Residual furfural was absent in the agricultural waste after harvest. Furfural is quickly broken down by soil microorganisms under aerobic conditions; hence, it is not toxic to the environment

Nematicidal isochromane glycoside from Kigelia pinnata leaves

Synthetic nematicides such as oxamyl and carbofuran play significant roles in the management of plant-parasitic nematodes. However, their negative environmental impacts have it imperative to search for safer alternatives. As part of our contribution in the search for bio-nematicides, compounds from plant extract were screened for possible potent nematicidal agent. A new isochromane carboxylic acid glycoside, isolated from the leaves of Kigelia pinnata (Lam.) Benth (Bignoniaceae) was evaluated for its nematicidal activity. The structure of the proposed compound was characterized by various spectroscopic methods, which included UV, FTIR, 1D-, and 2D-NMR, FAB-MS, TOF-ESI-MS and TOF-ESI-MS/MS (TANDEM). The in vitro experiment conducted on the glycoside against Meloidogyne incognita juveniles and eggs indicated an induced mortality. Its activity can be compared favourably with oxamyl, when tested at 0.1 mg/mL concentration. At four hours of observation, no significant difference (P &lt; 0.05) between oxamyl and the glycoside was observed. The present data sustains that natural glycoside is a promising oxamyl alternate for controlling nematode-induced plant root knots and may contribute to integrated pest management.</p