Influence of organic manures and fertilizers on the incidence of sucking pests of sunflower, Helianthus annuus L.

To assess the influence of certain organic amendments on the incidence of sucking pests of sunflower, Helianthus annuus viz., leafhopper, Amrasca biguttula biguttula and whitefly, Bemisia tabaci. Application of farm yard manure @ 12.5 t ha⁻¹ alone and in combination with biofertilizers (2 kg ha⁻¹), vermicompost (250 kg ha⁻¹) + biofertilizers (2 kg ha⁻¹) and neem cake (250 kg ha⁻¹) reduced the incidence of leafhopper and whitefly against the application of NPK straight synthetic fertilizers. The organic amendments comparatively increased the total phenols in the plant and also the activity of enzymes viz., polyphenol oxidase and peroxidase, which might be responsible for the reduced pest incidence. The results provided an insight into the manipulation of host plant ecology through host plant nutrition to accord resistance in plants against the insect pests.