Residual water deficit as one of the criteria for estimating drought resistance of maize lines and hybrids

Agricultural drought is defined as the lack of soil moisture to ensure the growth and development of agricultural crops. The relevance of developing drought-resistant maize hybrids is increasing due to ongoing global climate change and the expansion of the maize growing area. The efficiency of this breeding direction largely depends on the availability of the initial material and, consequently, on the accuracy of the estimation methods used. The purpose of the current study was to determine the drought resistance of the initial material of self-pollinated maize lines and hybrids. The paper has presented the study of drought resistance of vegetative maize plants by the method of residual water deficit (RWD) in 2022–2024. The study was conducted at the Agricultural Research Center “Donskoy”, located in a area with unstable moisture levels, which allowed selecting genotypes with resistance to water deficit under natural aridity. The objects of the study were 170 maize samples, including 80 hybrids in the Competitive Variety Testing and 90 lines of the working collection of the hybridization nursery. There have been identified 29 hybrids with low water deficit, both in the flowering stage (3.59–8.92 %) and in the milky-wax ripeness stage of grain (4.01–14.54 %), and 25 lines with low RWD values in the flowering stage (4.09–10.86 %) and its insignificant increase (0.02–2.0 %) to the milky-wax ripeness stage under drought increase. The identified maize lines and simple hybrids with high levels of drought tolerance could be recommended for crossing schemes to develop three-line hybrids adapted to water stress.