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

摘要

Field experiments were conducted in Tamil Nadu, India, to assess the influence of certain organic amendments on the incidence of sucking pests of sunflower, i.e. the leafhopper (Amrasca biguttula biguttula) and whitefly (Bemisia tabaci). Applications of farmyard manure at 12.5 t/ha, alone and in combination with biofertilizers (2 kg/ha), vermicompost (250 kg/ha) + biofertilizers (2 kg/ha) and neem cake (250 kg/ha), reduced the incidence of leafhopper and whitefly against the application of NPK synthetic fertilizers. The organic amendments comparatively increased the total phenols in the plant and also the activity of the enzymes polyphenol oxidase [catechol 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..