Response of Pratylenchus spp Infected Tomato (Lycopersicon esculentum Mill) to Organic Compounds from Mangifera indica

Abstract

The need to reduce the negative impact of synthetic nematicides on the environment necessitated the search for bio-pesticides. This study was conducted to evaluate the nematicidal potential of chromatographic fractions from Mangifera indica on tomato in the screenhouse and field. M. indica bark was extracted with ethanol (EtOH) and dichloromethane (DCM). The crude extracts were chromatographed and fractionated on silica-gel (100-120mesh) column.  Fractions were tested at 0.2, 0.5 and 0.8mg in the screenhouse and 12, 18 and 24mg on the field. Vegetative growth was significantly (p<0.05) higher in plants treated with the highest concentration of fractions. There was a significant increase in number of fruits per plant and fruit weight per plant. Nematode population in soil and root also reduced significantly. The fractions were partially characterised and were found to contain fatty acid esters, hydrocarbons, terpenoids, flavonoids, alkaloids, acids, esters, aldehydes and ketones. Observed reduction in nematode population is a clear indication that M. indica bark extract is an effective agent against nematode infestation.

Key Words: Lycopersicon esculentum; Mangifera indica; Pratylenchus spp; ethanol; dichloromethane