Screening amaranth genotypes (Amaranthus Spp.) for yield, quality and resistance to biotic stress

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Date
1998
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Department of Horticulture, College of Agriculture, Vellayani
Abstract
The present investigation on “Screening amaranth genotypes (.Amaranthus spp.) for yield, quality and resistance to biotic stress” was carried out at the College of Agriculture, Vellayani during 1997-98. Sixty diverse genotypes of amaranthus collected from different parts of the country were initially evaluated for biotic stress tolerance viz., leaf blight caused by Rhizoctonia solani and leaf webber, yield and yield attributes. Selection index was worked out using five important characters viz., yield, leaf / stem ratio, days to 50 per cent bolting, reaction to leaf blight and leaf webber. Based on the selection index values and specific merit / demerit of the accession, 15 genotypes were selected and were evaluated in a randomised block design with three replications for yield, yield attributes, quality characters, antinutrient factor - oxalate, and reaction to leaf blight and leaf webber. The GCV, PCV heritability and genetic gain were also worked out for different characters. The accessions A 22, A 26, A 29 and A 61 (Co-1) were found to be free of leaf blight incidence in the initial evaluation trial. The attack of leaf webber was mild. The highest yield was recorded by A 57 followed by A 53 and A 58. The genotypes were catalogued morphologically using a standard descriptor. The results of the second experiment showed significant difference among the fifteen genotypes for all the 24 characters studied except leaf webber incidence. The genotypes A 22, A 26, A 29 and A 61 (Co-1), all belonging to Amaranthus dubius were found completely resistant to leaf blight in this experiment also. The same genotypes A 61, A 29, A 22 and A 26 were the top yielders in order of merit. The leaf / stem ratio was maximum for the accession A 66 followed by A 80 (Arun). These accessions also recorded high protein and vitamin A content. The antinutrient factor, oxalate was lowest for A 63 {A. tristis cv. CO-3). Leaf webber incidence was mild and did not cause any economic loss. High values of PCV and GCV were obtained for most of the characters studied. High heritability coupled with high genetic gain was observed for length of leaf lamina, leaf width, leaf weight, fibre, oxalate and reaction to leaf blight, indicating scope for improvement through selection. Plant height, stem girth, length of leaf lamina, leaf width, leaf / stem ratio, total leaf weight and stem weight were found to be highly correlated with yield. Path analysis study revealed strong and positive direct effect of plant height, stem girth and leaf / stem ratio on yield. The genotypes A 22, A 26, A 29 and A 61 all belonging to A. dubius which were found elite due to their superiority in yield, low oxalate content and resistance to leaf blight, can be recommended for commercial cultivation in the endemic areas of the state.
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171356
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