The efficacy of ethanol extracts from four plants, Dennettia tripetala Baker, Eugenia aromatica Baillon, Piper guineense Thonn et Schum and Anchomanes difformis P. Beauv. as bioinsecticides for control of adult Sitoph...The efficacy of ethanol extracts from four plants, Dennettia tripetala Baker, Eugenia aromatica Baillon, Piper guineense Thonn et Schum and Anchomanes difformis P. Beauv. as bioinsecticides for control of adult Sitophilus zeamais Motschulsky, Tribolium castaneum Herbst, Callosobruchus maculatus Fabricius, Oryzaephilus mercator Fauvel and Lasioderma serricorne Fabricius were determined at two concentrations (0.5% and 2.0%) in the laboratory. All extracts were toxic to beetles with E. aromatica being the most potent of four plant materials tested and had the least LT 50 value. This was followed by A. difformis extract. At 2.0% v/w extract concentration, percentage grain damage by insects in treated grains stored for 90 days was nil. Grains protected with A. difformis had the least percentage seedgerminationof62.50%whilethoseprotectedwithP.guineensehadthehighestpercentagegermination(74.58%)at2.0% extract concentration. The mean percentage germination in the control was 72.72%. Treatment of grains with plant extracts had no significant (P>0.05) effect on its water absorption capacity.展开更多
Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle C...Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle Callosobruchus maculattts （Fabricius）. Crude stem extracts at 3% concentration showed high contact toxicity to adult beetles within 24 h after application, while it was moderately toxic to the beetles at the lowest （1%） concentration. At the highest application rate, the plant extract provided good protection to grains stored for 90 days. Grain viability and water absorption capacity were not affected by treatments with ethanol extracts ofA. difformis. The significance of these findings is discussed in relation to biopesticide-means of controlling cowpea bruchids.展开更多
文摘The efficacy of ethanol extracts from four plants, Dennettia tripetala Baker, Eugenia aromatica Baillon, Piper guineense Thonn et Schum and Anchomanes difformis P. Beauv. as bioinsecticides for control of adult Sitophilus zeamais Motschulsky, Tribolium castaneum Herbst, Callosobruchus maculatus Fabricius, Oryzaephilus mercator Fauvel and Lasioderma serricorne Fabricius were determined at two concentrations (0.5% and 2.0%) in the laboratory. All extracts were toxic to beetles with E. aromatica being the most potent of four plant materials tested and had the least LT 50 value. This was followed by A. difformis extract. At 2.0% v/w extract concentration, percentage grain damage by insects in treated grains stored for 90 days was nil. Grains protected with A. difformis had the least percentage seedgerminationof62.50%whilethoseprotectedwithP.guineensehadthehighestpercentagegermination(74.58%)at2.0% extract concentration. The mean percentage germination in the control was 72.72%. Treatment of grains with plant extracts had no significant (P>0.05) effect on its water absorption capacity.
文摘Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle Callosobruchus maculattts （Fabricius）. Crude stem extracts at 3% concentration showed high contact toxicity to adult beetles within 24 h after application, while it was moderately toxic to the beetles at the lowest （1%） concentration. At the highest application rate, the plant extract provided good protection to grains stored for 90 days. Grain viability and water absorption capacity were not affected by treatments with ethanol extracts ofA. difformis. The significance of these findings is discussed in relation to biopesticide-means of controlling cowpea bruchids.
