Effect of altered leaf angle on maize stalk lodging resistance

Abstract

AbstractIncreasing light intensity in the mid and low canopy can improve maize (Zea mays L.) stalk lodging resistance. Field experiments involving altered leaf angle were designed to explore how leaf angle affects the light distribution within the canopy, stalk carbohydrate accumulation, stalk strength formation, and grain yield. When the leaf area was constant and the average leaf angle was decreased by ∼10° above the ear leaves and increased by ∼25° at the ear leaves and below, the photosynthetically active radiation (PAR) at the ear layer increased by 41–62%, and the interception of PAR (IPAR) below the ear increased by 107–229%. Average cellulose content of the third and fourth internodes increased by 13–21%, whereas lignin content increased by 9–30%. The rind penetration strength (RPS) of the third internode increased by 13–21%, whereas the crush strength (CS) of the fourth internode increased by 15–27%. These changes resulted in a reduction of 6–11% in the lodging percentage. The grain yield increased by 15–27% because of increases in kernel number and kernel weight. Therefore, under close planting, selecting a maize ideotype with upright leaves in the upper canopy and flat leaves in the lower canopy is conducive to rational radiation allocation in the maize canopy. This would facilitate structural carbohydrate accumulation and mechanical strength formation while improving lodging resistance and grain yield.