High Humidity and Mites Blamed for Widespread Alternaria Disease in Apple Crops
Shimla – As the apple season begins, apple growers in Himachal Pradesh are facing a severe crisis. An outbreak of Alternaria disease has affected up to 95 percent of apple plants in some of the region’s key growing areas, including Rohru, Kotkhai, Jubbal, Chopal and Theog. This alarming situation was uncovered following inspections by teams from Dr. YS Parmar Horticulture and Forestry University Nauni.
The disease, which manifests as brown and black spots on the apples, has led to premature fruit drop, causing significant concern among the apple-growing community. The symptoms first appear on the leaves, where circular dark green spots develop on the upper surface. These spots gradually turn brown and then dark brown, while the rest of the leaf turns yellow. As the disease progresses, the leaves fall prematurely, affecting the fruit’s growth and quality.
Dr. Sanjay Chauhan, a subject matter expert from the Horticulture Department, explained the gravity of the situation: “Alternaria disease is very fatal for apples. The leaves will fall from the apple plant even before the apple is harvested, leading to completely spoiled fruit.”
A team from Krishi Vigyan Kendra (KVK) Shimla inspected orchards in about 20 villages of Rohru, Kotkhai, and Jubbal, identifying Alternaria disease based on observed symptoms. The infection rates varied across different orchards, with some experiencing up to 95 percent infection. The severity of leaf disease was found to reach up to 56.3 percent in certain areas. Another team reported infection rates between 60 to 70 percent in Theog, while the Chaupal and Nerwa areas showed significantly lower infection rates, with a maximum of 3 percent.
Dr. Usha Verma, in charge of KVK Rohru, attributed the spread of the disease to several factors. “The disease spread due to low rainfall conditions from November 2023 to July 2024 and intermittent rains in June 2024. Additionally, a high mite population stressed the plants, further increasing the incidence of leaf spot disease.”
Scientist Dr. Aarti Shukla pointed out that the improper use of chemical sprays had weakened the plants, making them more susceptible to disease. Dr. Shalini Verma added that growers who did not use department-approved fertilizers properly experienced a more severe outbreak of the disease.
The situation is dire for apple growers, who now face significant losses due to the premature fruit drop and spoilage caused by Alternaria disease. Urgent measures and support from agricultural authorities are needed to mitigate the impact and protect the remaining healthy orchards.
As the apple growers in Himachal Pradesh are going through a challenging period, the focus will be on finding effective solutions to control the disease and prevent further damage to the crops. The collaboration between apple growers and agri scientists will be crucial in overcoming this outbreak and ensuring the sustainability of apple farming in the region.
