Biochemical basis of resistance in arecanut genotypes against Raoiella indica Hirst
Indhusri Chavan, Pradeep S, Narayanaswamy H, Manjunatha M, Sridhara S and Kalleshwara Swamy CM
The experiment was carried out to assess the biochemical basis of resistance in response to the infestation by arecanut mite Raoiella indica. The impact of plant biochemical characters on the R. indica infestation, the various biochemical content of different arecanut genotypes were revealed that Thirthahalli local which scored highest mite population, significantly recorded higher nitrogen (5.97 %) crude protein (14.87 %) and moisture (56.71 %) content and lower levels of Phosphorous (0.16 %), potassium (0.87 %), crude fiber (26.16 %). Correlation studies revealed that there was positive and highly significant correlation was observed between R. indica population and nitrogen (r = 0.985*), crude protein (r = 0.979*) and moisture content (r = 0.986*) of the leaf. While potassium (r = -0.973*), crude fiber (r = - 0.961*), Phosphorous (r = - 0.973*) and phenol (r = - 0.956*) showed significant negative correlation. From the above results, it was proven that none of the genotypes screened were found to be completely resistant to mites. However, Vittal dwarf (11.80/cm2 of leaflet) and Sumangala (13.12/cm2 of leaflet) recorded significantly less number of mites, whereas Thirthahalli local (28.80/cm2 of leaflet) recorded the highest mite per cm2of leaflet.