Sweet potato varieties to diversify cultivars in Bhutan

Sweet potato (Ipomea batatas (L.) Lam) is an important root crop grown in the world. It provides carbohydrates, proteins, vitamins, fibre and essential minerals. With limited varieties available, and the crop being undocumented thus far, sweet potato production in Bhutan is insignificant and has not gained scope in agricultural food systems. For nutrient and crop diversification, three improved varieties from Japan, and a local variety as a check were evaluated under three different agro-ecological zones to ascertain their performance in terms of yield and other yield attributes. The experiment was laid out using Randomized Complete Block Design with four treatments each with three replications. There was no significant difference in yields between the varieties. Nonetheless, it was observed that orange flesh variety (Bajo kewa ngam II) outyielded (13.8t/ac) all other experimented varieties across all experimental sites. The variety orange flesh (Bajo kewa ngam II) followed by Beni Azumi (Bajo kewa ngam I) and Gorojima were the most preferred variety based on their yield potential, pests and diseases tolerance, organoleptic test (taste, texture and colour) and yield attributes. All the three varieties showed good yield stability.