Solan: Scientists from Dr. Y.S. Parmar University of Horticulture and Forestry (UHF), Nauni, have been conducting extensive field visits and awareness campaigns across Himachal Pradesh’s major apple-growing regions to help orchardists scientifically manage Alternaria leaf spot, Marssonina leaf blotch, apple scab, and other emerging diseases affecting apple crops. The awareness and advisory drive, which began on July 8, has been carried out in collaboration with officials from the Department of Horticulture.
Over the past two weeks, scientific teams have visited orchards, assessed disease incidence, examined leaf samples, and interacted directly with growers to provide location-specific recommendations. During the field inspections, scientists detected Alternaria leaf spot and Marssonina leaf blotch in some orchards, though the severity remained low. The teams also addressed farmers’ concerns regarding root rot, collar rot, yellowing of foliage, wilting, and bark decay, recommending improved field drainage, prevention of water stagnation, and adoption of prescribed management practices.
The field visits also highlighted several gaps in orchard management. Scientists observed that only a limited number of orchardists had conducted soil and leaf testing, with most fertiliser applications still based on traditional practices rather than scientific recommendations. This has resulted in nutrient imbalances in several orchards. In many cases, excessive use of phosphatic fertilisers appeared to have induced zinc deficiency. The teams also found that indiscriminate use of nutrient sprays, particularly when mixed with pesticides without technical guidance, was reducing spray effectiveness and, in some cases, increasing the risk of phytotoxicity.
Scientists further noted that many growers were not following the University’s recommended fungicide spray schedule and were relying heavily on advice from agrochemical retailers while planning plant protection measures. In several orchards, growers were unable to distinguish fungal diseases from damage caused by insects or mites, leading to the unnecessary use of insecticides and miticides instead of fungicides.
During interactions, some orchardists expressed concerns that fungicides recommended by the University were not providing effective disease control. However, university pathologists explained that in many cases the infection was confined to the leaf petiole rather than the leaf blade, resulting in inadequate spray coverage. They clarified that the issue was related to spray application techniques and coverage rather than the effectiveness of the recommended fungicides. Scientists also observed that in several orchards, fungicide spray intervals had exceeded the recommended 20-day schedule, contributing to disease spread.
The University has advised orchardists to adopt an integrated disease management approach that combines cultural, biological, and chemical methods. Farmers have been urged to regularly monitor orchards for disease symptoms, remove weeds, infected leaves, and leaf litter to improve orchard sanitation, and promote decomposition of fallen infected leaves using a five percent urea solution. Scientific pruning and canopy management have also been recommended to improve aeration and light penetration while ensuring timely management of root diseases, cankers, and insect-pest infestations.
Scientists have also emphasised the importance of scientific nutrient management through soil and leaf testing. Farmers have been encouraged to submit leaf samples for analysis between mid-July and mid-August and soil samples after harvest to enable site-specific fertiliser recommendations and balanced nutrient application.
The advisory further recommends strict adherence to the University’s fungicide spray schedule and maintaining the prescribed interval between sprays. Farmers have been cautioned against indiscriminately mixing fungicides with pesticides, micronutrients, growth regulators, or plant hormones unless specifically recommended, as such combinations may lead to phytotoxicity, fruit russeting, and reduced effectiveness of plant protection measures. Orchardists have also been advised to purchase pesticides only from authorised and licensed dealers and use products recommended by the University and the Department of Horticulture.
For preventive disease management, the University has recommended protective sprays of Metiram @ 600 grams per 200 litres of water or Ziram @ 500 grams per 200 litres of water. Under conditions of high disease pressure, growers have been advised to use recommended combination fungicides such as Lustre 5% SE, Cabrio Top 60 WG, Shamir, Kohicap Plus, Avtaar, Merivon, or LUNA Experience in the prescribed dosages, using these products alternately while avoiding unnecessary tank mixtures with other agrochemicals.
The University has also invited growers to seek expert guidance by sending photographs of disease symptoms and their queries via email to [email protected], enabling scientists to provide timely technical advice for effective disease management and healthier apple orchards.
