Delazari Fábio T, Assis Igor R, Cabrera Diego F V, Ferreira Mariane G, Dias Luiz E, Rueda Angelica, Zanuncio José C, Silva Derly J H
Universidade Federal de Viçosa, Centro de Ciências Agrárias, Departamento de Fitotecnia, Avenida P.H. Rolfs, s/n, Campus Universitário, 36570-900 Viçosa, MG, Brazil.
Universidade Federal de Viçosa, Centro de Ciências Agrárias, Departamento de Solos, Avenida P.H. Rolfs, s/n, Campus Universitário, 36570-900 Viçosa, MG, Brazil.
An Acad Bras Cienc. 2018 Oct-Dec;90(4):3541-3549. doi: 10.1590/0001-3765201820170687. Epub 2018 Sep 3.
The sweet potato is an alternative energy source, but its sustainability depends on efficient water use. The objective of this study was to evaluate sweet potato morpho-physiological characteristics, and water use efficiency (WUE). Irrigation depths of 50, 75, 100, and 125% of crop evapotranspiration (ETc) were applied. The morpho-physiological indicators, WUE, leaf area index (LAI), leaf water potential, leaf temperature, and leaf chlorophyll index (ICF), were evaluated. The WUE of the sweet potato cultivars increased until the 75% water depth of the ETc. The LAI of these cultivars increased with irrigation depth, with higher values at 100% of the ETc. The leaf water potential of the two sweet potato cultivars was lowest with the lower irrigation depth. Leaf temperature was closer to that of ambient temperatures in treatments with greater irrigation depth. The increase of the WUE with the greater accumulation of dry biomass is due to greater CO2 diffusion by stomata. The reduction in the growth of these plants is due to water stress limiting stomatal conductance, transpiration, leaf growth (LAI) and chlorophyll concentration, proportional to soil moisture conditions. The functional relationship between soil moisture and growth is essential to optimize irrigation management at different growth stages.
红薯是一种替代能源，但其可持续性取决于水分的高效利用。本研究的目的是评估红薯的形态生理特征和水分利用效率（WUE）。施加了作物蒸散量（ETc）的50%、75%、100%和125%的灌溉深度。对形态生理指标、水分利用效率、叶面积指数（LAI）、叶片水势、叶片温度和叶片叶绿素指数（ICF）进行了评估。红薯品种的水分利用效率在ETc水深达到75%之前有所提高。这些品种的叶面积指数随灌溉深度增加，在ETc的100%时具有更高的值。两个红薯品种的叶片水势在灌溉深度较低时最低。在灌溉深度较大的处理中，叶片温度更接近环境温度。水分利用效率随着干生物量的更多积累而增加，这是由于气孔对二氧化碳的扩散作用增强。这些植物生长的减少是由于水分胁迫限制了气孔导度、蒸腾作用、叶片生长（叶面积指数）和叶绿素浓度，这与土壤湿度条件成比例。土壤湿度与生长之间的功能关系对于优化不同生长阶段的灌溉管理至关重要。
