Adaptation of New Adzuki Bean Variety for Organic Production System in Bhutan

Abstract

Adzuki bean (Vigna angularis Willd.) is a native legume that is cultivated by subsistence Bhutanese farmers as one of the many other pulses for household food security. Several scientific literatures have revealed that many Bhutanese Adzuki bean germplasm has been assessed for genetic variability confirming that Adzuki bean is native to Bhutan. The cultivation of Adzuki bean currently is confined to small areas as a marginal crop for household consumption. The drive towards a certified organic production system in Bhutan has called for an urgent need to adapt, release and promote organic technologies, particularly on organic pests and diseases, and sustainable soil fertility management. Adaptation of high-yielding Adzuki bean varieties and their commercialization as a health food, high-value crop for export, and a good source of nitrogen for sustainable soil fertility management was studied. One new Japanese variety Erimo was rapidly evaluated in the researcher-managed and farmer-managed trials under the organic production system at different locations. The seed yield in the researcher-managed trial was significantly different over locations (P<0.05) and ranged from 540 to 1215 kg ac-1 with a mean yield of 907.50 kg ac-1. Under the farmer-managed trials in the 2020 season, seed yield ranged from 150 to1080 kg ac-1 with a mean of 431.40 kg ac-1. The days to crop maturity ranged from 104 to 126 days which fits well into the farmers’ existing cropping system. The 23rd Variety Release Committee (VRC) of the DoA endorsed the release of this variety Erimo with the local name Yusi-Adzuki. This variety will be promoted for commercial cultivation for export to Japan, and as a sustainable soil fertility management technology in the organic production system.