Epidemiology, Source of Resistance and Management of Blue Mould Rot Disease of Aonla (Indian Gooseberry) to Identify Research Priorities and Knowledge Gaps, a Review

Abstract

Earlier, the blue mould rot was a minor disease but now it becomes a major disease of Indian gooseberry. The effect of weather parameters i.e. temperature and relative humidity on disease development were studied, in vitro.The combination of 30 ºC temperature with cent per cent relative humidity resulted in maximum disease incidence of 87 and 100% in both 5 and 10 days after inoculation (DAI), respectively. Minimum disease intensity (15 and 22%) was recorded at 10 ºC temperature and 40 per cent relative humidity at 5 and 10 days after inoculation. However, with further increase in temperature and relative humidity, the per cent disease intensity was also increased and it also increased during the period of time (5 and 10 days after inoculation) clearly elucidated that low temperature (10 ºC) with low relative humidity (40%) is ideal for the post harvest storage of Indian gooseberry. A minimum number of 50 spores/ml was necessary for disease initiation. The resistance and susceptibility against the blue mould rot (P. islandicum) disease can be varied among the varieties of E. officinalis suggesting that the resistant ones should be preferred for further plantation activities to avoid the frequent damage and losses caused by the disease. Relative efficacy of chemicals, plant extracts and bio-agents against blue mould rot tested in vitro and in vivo at different concentrations revealed that boric acid (chemical) at 1.0 M concentration, neem leaf extract (plant extract) at 20 per cent concentration and Trichoderma harzianum were exhibited the best to inhibit growth in pre- and post-inoculation after five and ten days of inoculation in both test conditions.