RHIZOSPHERE AND RHIZOPLANE MICROFLORA OF COFFEE SEEDLINGS AS INFLUENCED BY COLLAR ROT AND BY SEED PRE-TREATMENT

Abstract

Rhizophere and rhizoplane microflora of coffee seedlings were studied by the dilution plate technique. The number of fungi, yeast and bacteria was higher in the rhizosphere than in the non-rhizosphere and rhizoplane. Rhizoctonia solani, the incitant of collar rot of coffee seedlings, altered the rhizosphere and rhizoplane microflora. The microflora of coffee seedlings obtained from seeds pre-treated with Carboxin and Quintozene markedly differed from that of seedlings with no seed treatment. Among the fungi isolated, Aspergillus spp. were the most predominant followed by Fusarium spp. R. solani was observed in the rhizosphere and rhizoplane of the untreated and collar rot-infected seedlings only. Seed treatment with fungicides decreased the fungal flora associated with plant roots.