Grain yield and root characteristics of summer maize (Zea maysL.) under shade stress conditions

Abstract Low light is a major adversity affecting yield and quality of summer maize in the Huang‐Huai‐Hai region of China. We conducted a field experiment to explore the effects of shading on root development and yield formation in two summer maize hybrids ( Zea mays L.), Denghai605 ( DH 605) and Zhengdan958 ( ZD 958). The experiment consisted of four treatments ( CK : ambient sunlight, S1: shading from tasselling to physiological maturity stage, S2: shading from six‐leaf to tasselling stage, S3: shading from seeding to physiological maturity stage). Shading had a strong impact on the development of roots in the upper soil layer. Shading significantly decreased the root dry weight, root/shoot ratio, root length density, root absorption area and active absorption area. The results showed that treatments in a diminishing sequence of effects on root from S3, S1, S2 to CK . Overall, shading decreased the root morphologic and activity indices, and decreased yield in summer maize. During an average of 2 years, yields of ZD 958 in S3, S2 and S1 decreased by 85%, 24% and 55%, yields of DH 605 in S3, S2 and S1 decreased by 87%, 26% and 67%, in compare to CK . The results will be useful for hybrid selection and improving cultural practices for enhancing the maize shading resistance in Huang‐Huai‐Hai region.