Effects of planting density, fertilization and growing season on the nutritional composition of 10 quinoa varieties ( Chenopodium quinoa Willd.) cultivated in the Central Highlands of Vietnam

Abstract

Quinoa (Chenopodium quinoa Willd.) has been grown and used as a food ingredient in Europe and South America for thousands of years and some varieties have recently been found suitable to grow under tropical conditions of Asian countries including Vietnam. This study aimed at investigating the variation in nutritional quality (protein, starch, fat, fibre and mineral contents) of quinoa seeds from 10 varieties as affected by different growing factors including planting density, fertilization and growing season in Dak Lak province, Vietnam. The results showed that the growth of quinoa in rainy season (August to November) with the planting density of 66,666 plants/ha using the fertilizing formulation of "120 kg N + 60 kg P2O5 + 105 kg K2O + 1000 kg organic compost + 500 kg of lime powder"/ha/crop resulted in the highest yield and nutritional quality of quinoa seeds. Atlas variety produced the highest yield with the highest protein content (22.7 %) while Lucas boldo variety had the highest fat content (4.4%) and Isluga variety showed the highest mineral content (9.4%) among others. The starch content of the varieties was comparable and ranged from 57.7 to 60.2%. These findings suggest that quinoa can be a new promising crop for agriculture development in Vietnam.