|Author:||Ekanayake, I. J. ; Collins, W.|
|Book Group Author:||NA|
Sweet potato is sensitive to water deficit stress. Conversely, the use of drought resistant genotypes and better water management practices can enhance its' root quality and yield. The response of sweet potato genotypes Chiappe, Paramutai, De armero, Centennial, Guiador, Superstar, Maleno and Japones-portugues to 4 seasonal irrigation regimes, using a line-source irrigation system during 3 summer crop seasons were evaluated in Lima, Peru. The significant genotypic (G) differences, irrigation (I) effects, and G × I interaction effects were observed for leaf water potential (y) indicating different internal tissue stress levels in various irrigation treatments. Dry root yield and dry matter, root nitrogenous compounds (protein nitrogen, non-protein nitrogen, and total nitrogen), and root carbohydrates (reducing sugars, total sugars, and starch) were significantly altered by irrigation treatments. Three types of genotypic response models to irrigation were compared using multivariate and covariance analyses. The genotypic response patterns to seasonal irrigation effect were linear and significant for dry matter (negative; P<0.01), total nitrogen (positive; P=0.02), and non-protein nitrogen (positive; P=0.04). Drought stress significantly reduced nitrogenous compounds and root yield. In contrast, root dry matter increased as water stress increased and was the most sensitive root quality trait. It served as the best indicator and selection criterion for drought resistance. Breeding efforts to select newly improved sweet potato cultivars with high dry matter content is thus warranted in drought-prone tropics.
|Pages:||243 - 248|
|Journal:||Journal of Food, Agriculture & Environment|
carbohydrates, chemical composition, crop quality, cropyield, drought resistance, dry matter, genotypes, irrigation systems,leaf water potential, nitrogenous compounds, plant composition, plantwater relations, reducing sugars, roots, starch, sweet potatoes, waterstress, Peru, Ipomoea batatas, Ipomoea, Convolvulaceae, Solanales,dicotyledons, angiosperms, Spermatophyta, plants, eukaryotes, SouthAmerica, America, Developing Countries, Andean Group, Latin America,chemical constituents of plants, drought tolerance, saccharides, FieldCrops (FF005) (New March 2000), Plant Breeding and Genetics (FF020),Plant Water Relations (FF062), Environmental Tolerance of Plants(FF900), Soil Water Management (Irrigation and Drainage) (JJ800)(Revised June 2002) [formerly Soil Water Management], Crop Produce(QQ050), Food Composition and Quality (QQ500)