Evaluation of vegetable amaranthus (Amaranthus dubius Mart. ex Thell.) in the humid tropics of Kerala

Abstract

Amaranthus, belonging to the family Amaranthaceae is one of the most nutritious leafy vegetable widely cultivated throughout India. The genus Amaranthus consists of about 60 species of which Amaranthus tricolor L., A. dubius Mart. ex Thell. and A. tristis L. are the major ones cultivated as vegetable. The grain amaranthus species, viz., A. hypochondriacus L., A. caudatus L. and A. cruentus L. are used as vegetable in the tender stage to some extent. However, in Kerala, the red leaved A. tricolor, a native of India remains the best choice. The widespread occurrence of leaf blight caused by Rhizoctonia solani characterized by dull white spots on the leaves which later coalesce together reducing its marketability is the major constraint in its production especially during the two monsoons. Earlier studies using a wide germplasm of 65 genotypes including Amaranthus tricolor, A. tristis, A. dubius and weedy species indicated that the species A. dubius the only polyploid species (2n = 64) was resistant to the leaf blight disease (Priya, 6).