Influence of Silica nutrition on the population of natural enemies of groundnut (Arachis hypogaea L.)

Abstract

Foliar application of calcium silicate @ 2.0, 3.5 and 5.0%, soil drenching of calcium silicate @ 10.0, 15.0 and 20.0% and a combination of foliar and soil drenching @ 2.0% + 20.0%, 3.5% + 15.0% and 5.0% + 10.0% were evaluated on 20 day old groundnut plant (Cv. VRI 2) and compared with untreated check during April 2015 – July 2015 with a weather condition of 30 ± 20C and 79 ± 5% RH at farmers’ holdings, Azhagarkovil, Madurai District, Tamil Nadu, India. Application of calcium silicate @ 2.0, 3.5 and 5.0%, soil drenching of calcium silicate @ 10.0, 15.0 and 20.0% and combination of foliar and soil drenching @ 2.0% + 20.0%, 3.5% + 15.0% and 5.0% + 10.0% on 20 days after dibbling of groundnut was on the activity and diversity of natural enemies viz., coccinellids (Cheilomenes sexmaculatus (L.) and Coccinella transversalis Fabricius), spiders (Oxyopes salticus Hentz) and Chrysoperla zastrowi sillemi (Esben-Peterson) in groundnut ecosystem, all treatments including untreated control recorded equal population of natural enemies and also per cent field recovery of Trichogramma chilonis Ishii and T. japonicum were almost equal.