Standardization of Summer Grafting Dates in Apple Under Polyhouse Conditions in Mid-Hill Areas of Himachal Pradesh

Abstract

Almost all the temperate fruit plants are grafted during dormant season or early spring including apple, however, in a preliminary studies carried-out at CSKHPKV, Palampur revealed that apple plants can be grafted during active growing season under protected conditions. Keeping in view, the present study was thus carried out to standardize the different summer grafting dates in apple cultivar Scarlet Gala onto seedling rootstocks under polyhouse conditions with the aim to reduce nursery production duration and to ensure the regular supply of plants to the growers. For this study, a tongue grafting was performed during summer months (May, June and July) on different dates. Among various dates, tongue grafting performed on June 12,22 and July 1 gave 100 percent bud take success with proper wound healing of graft unions. The plants grafted on June 12 attained maximum height (71.17 cm) at the end of growing season however; it was statistically at par with plants grafted on June 22 and July 1. Similarly, the number of laterals and root length was also found maximum in plants grafted on these dates. The various foliar characteristics of the plants were also significantly affected by grafting dates. The leaf area, fresh and dry weight of leaf and number of leaves per plant were observed maximum in those plants which were having vigorous growth with more number of lateral shoots. In conclusion results showed that tongue grafting performed in second week of June to first week of July is the best time for performing summer grafting in apple under polyhouse conditions in mid hill areas of Himachal Pradesh when both components (scion and rootstocks) are in active growing stage. Further, this technique can be applied for quick multiplication of nursery plants of apple for reducing nursery production duration under polyhouse conditions provided the availability of scion wood in mother orchards during grafting operations.