Evaluation of grafting performances in Persian walnut affected by grafting methods and covering materials in Mugu district, Nepal

Abstract

Walnut carries a great potential for cultivation in the high hills of Nepal, including the Mugu district. However, progress has not been as expected. Low graft survival rate and poor grafting practices account for inadequate number of quality saplings and consequently unreasonable price for successful ones. In this context, a field-based research was conducted in a two-factorial Randomized complete block design (RCBD) at Chhayanath Rara, 03, Mugu, to determine the suitable grafting method and covering material for grafting in walnut. Four different grafting methods viz. Tongue, saddle, cleft, and splice along with sawdust and grafting tape as graft covers were employed as treatments. The tongue grafting method yielded the highest callused rate (68.07%) and the highest graft take rate (48.07%). Similarly, sawdust used as a graft cover produced the most promising results on both the callused rate (56.37%) and the graft take rate (44.27%). Furthermore, the use of sawdust cover was found to have a greater callus quality (2.78) compared to that of using a grafting tape. No statistical differences were obtained in saleable plant rate and days to bud burst as a result of either of the factors. Apart from callus quality, the interaction between the two factors did not produce considerable variation in any of the variables. Hence, this study suggests the application of the tongue grafting method, along with the use of sawdust as a graft cover for enhanced grafting performance in agro-climatic zones similar to Mugu.