Constraints of apple cultivation in Lahaul & Spiti district of Himachal Pradesh

Apple cultivation in Lahaul & Spiti district of Himachal Pradesh is in vogue for quite some time now. At present, the apple orchards are rapidly increasing primarily in the Pattan valley. Large scale cultivation of apple holds the potential to transforming the economy of the tribal people with good returns from the apple orchards as compared to wilt and blight prone cash crops of peas and potato, respectively. But, apple cultivation in the valley is also fraught with multiple problems of insect-pests, diseases and micronutrient deficiency disorders. During visits to various apple orchards in different localities throughout Lahaul and Spiti valleys between 2008–2011, many problems relating to insect-pests, diseases and micronutrient deficiency disorders have been observed. The insect-pests that have been recorded on apple in the twin valleys of Lahaul and Spiti include Sanjose scale (Quadraspidiotus perniciosus Comstock), wooly apple aphid (Eriosoma lanigerum Hausmann), leaf roller (Archips sp.), red spider mite (Tetranichus urticae Koch.), fruit moth (Argyresthia conjugella Zeller) and blotch leaf miner (Phyllonorycter sp). Amongst diseases, hairy root (Agrobacterium rhizogenes), collar rot (Phytophthora cactorum), powdery mildew (Podosphaera leucotricha), bark canker (Botryosphaeria dothidea) and scab (Venturia inaequalis) have been noticed. The micronutrient deficiencies that have been observed in apple orchards almost throughout the valleys relate to boron and zinc. The deficiencies of these micronutrients are making the apple plants more vulnerable to diseases like bark canker (Botryosphaeria dothidea). The boron deficiency symptoms are manifested on the affected apple plants in the form of thick, brittle and dark green leaves at the shoot tips. Whereas, zinc deficiency causes the newly formed leaves to remain small in size with elongated shoot that give appearance of rosette leaf at tip.