Fungicidal and insect controlling properties of Proteus strain RRLJ 16, isolated from tea, Camellia sinensis (L) O Kuntze, plantations

Abstract

A strain of Proteus RRLJ 16, isolated from acid (pH 4.5-5.5) iron rich tea (Camellia sinensis) plantation soil, produced siderophores with single absorption peak at 370 nm when cultured in iron free medium. Extracted crude fraction of siderophores and live cultures showed in vitro antibiosis against five species of pathogenic fungi. When the strain was cultured in a normal bacteriological medium without iron stress, it produced an insect repellent compound. The culture filtrate sprayed (dilution of 1:100 in water) on tea plants infected with pink mites or green flies, the insect populations disappeared from the plants. Termite galleries sprayed similarly showed no termite activity after 24 hr of spraying. No reinfestation by insects was observed on treated plants for more than one year.