Bio management of root rot in Coleus forskohlii caused by Macrophomina phaseolina

Abstract

Coleus forskohlii is an important medicinal plant native to India, which contains forskolin as an active ingredient in their roots. The crop has a great potential in future due to the expected increase in demand for forskolin which is widely used in glaucoma, cardiac problems, eczema, asthma, and hypertension and in the treatment of cancers. However, the crop has not become very popular among farmers because of its susceptibility to many diseases of which root- rot/wilt is the most important, causing serious losses to crop and affecting the tuber yield. Root rot/wilt is the major disease of C. forskohlii causing heavy losses (>50%) in south India. Biological control of the root rot diseases would be the only sustainable and potential control strategy to combat with the disease. Hence, the present study was conducted to find out effective bio agents for the management of root rot disease in coleus. The results revealed that basal soil application of Bacillus subtilis (Bbv 57) @ 2.5 kg/ha+ dipping root cuttings in 0.2% (Bbv 57) + soil application of Bbv 57) @ 2.5 kg/ha at 90 days after planting followed by treatment T1 with basal soil application of (SA) of B. subtilis (Bs1) @ 2.5 kg/ha + dipping cuttings in 0.2% B. subtilis (Bs1) + soil application of B. subtilis (Bs1) @ 2.5kg/ha was significantly superior in reducing the root rot incidence and in increasing the tuber root yield.