Impact of Shoot Pruning and Paclobutrazol on Incidence of Sooty Mould of Mango Cultivars

Abstract

Three mango cultivars viz., Himsagar, Bombai and Langra were selected against sooty mould under natural field condition without any control measures. The Sub-Himalayan Terai region of West Bengal is experienced with a high annual rainfall (2500-3500mm) along with high humidity particularly during rainy season which may causes more chance of pest and disease infestation. There is very meagre information on scientific literature regarding the incidence of diseases and pests as well as their prevalence after shoot pruning on this sub Himalayan Terai region of West Bengal. Disease severity of mango was measured at monthly interval after shoot pruning (30cm  from the shoot tip) and paclobutrazol application of plants and the cultivars were grouped under different degrees of resistance on the basis of per cent disease index (PDI) using 0-4 scale. The observations on per cent disease index (August to July) were recorded. Pooled data of 2019-20 and 2020-2021 the maximum sooty mould severity was recorded in cv. Bombai (48.11% and 38.48%) in September, followed by Langra (40.97% and 34.21%) in July month. In Himsagar (35.57% and 28.45%) disease recorded in (untreated and paclobutrazol treated plants) the month of September respectively. Where as minimum in cv. Himsagar (14.80% and 11.79%) in March followed by Langra in April month in control (15.65%) and in march month of PBZ treated plants (13.86 %). Among the all cultivars maximum average per cent disease index (Avg. PDI %)    recorded in Bombai (34.93% and 25.94%) followed by Langra (27.16% and 22.84%). Whereas, minimum recorded in cv. Himsagar (26.38% and 20.05%) in control and PBZ treated plants in both the years 2019-20, 2020-21 respectively. PBZ treated plants of Himsagar showed moderate resistant reaction and control plants showed moderate susceptible reaction as well as PBZ treated plants of cultivars Langra and Bombai showed moderately susceptible reaction but control plants of same cultivars showed susceptible reaction.