Effect of Temperature, Soil Moisture and Elevated CO_2 on Growth of Rhizoctonia bataticola and Dry Root Rot Disease of Chickpea in Karnataka State

摘要

Dry root rot caused by Rhizoctonia bataticola is becoming an emerging disease as per the new reports and considered as potential threat to chickpea productivity and production under changing climatic scenario. The identity of pathogen was confirmed molecularly using ITS-1 and ITS-4 primers which produced amplified product size of 500-650 bp in all three isolates indicating that all the isolates belonged, to species Rhizoctonia bataticola. The maximum colony growth of R. bataticola and the dry root rot disease severity was recorded at 30-35 °C which is considered as optimum temperature range for growth of pathogen and development of disease. Highest severity of dry root rot and lesser plant growth parameters such as root length, shoot length and total biomass were observed at 40-60 per cent soil moisture regimes, irrespective of type of soil. Further, elevated C02 @ 550 ± 25 ppm with 2 °C rise in temperature recorded higher dry root rot well as reduced growth parameters of chickpea. With respectto correlation studies, increase in the temperature lead to decreased radial growth of pathogen and dry root rot disease incidence. It is also inferred that increase in the soil moisture led to increase in growth parameters in both black as well as red soils.