Effect of soil solarization on viability, disease incidence and incubation period of stem rot of chrysanthemum caused by R. solani

A study conducted during 2016 at Nauni to find out the effect of soil solarization with transparent polyethylene mulch (25µm thick) was recorded on soil temperature in the earthen pots and pathogenic potential of the stem rot pathogen mixed in the soil of the earthen pots. Soil solarization increased average maximum soil temperature to 45.9 °C, in the year 2016 with an increase of 7.8 °C at 5 cm soil depth over unsolarized pots. Soil solarization for 40 days resulted in significant reduction in the potential of the pathogen to cause the disease. Soil solarization was observed on disease causing capability of the stem rot pathogen. Sclerotia of Rhizoctonia stem rot pathogen subjected to soil solarization with transparent polyethylene sheet which were put at 5 cm soil depth for 40 days lost the viability of by 88.7 per cent in comparison to unsolarized soil in the pots. Sclerotia of the stem rot pathogen subjected to soil solarization with transparent polyethylene sheet at 5 cm soil depth for 40 days increased the incubation period of the disease by 21.2 per cent i.e. symptoms were delayed and reduced the disease incidence by 46.1 per cent in comparison to unsolarized pots.