Effect of Leaf Orientation, Leaf area, and Plant Densities on Corn Production1

Abstract

AbstractThe effect of corn (Zea mays L.) leaf orientation on grain yield and production practices has been the subject of conflicting reports over the past few years. Plant population is reported to be the cause of the discrepancies. The objectives of the present study were to determine the effect of plant population and leaf orientation on corn plant efficiencies and their interaction. Two contrasting leaf angles were compared by the use of near‐isogenic versions of the single‐cross hybrid (Hy2 ✕ C103) consisting of the liguleless (lg2) and its normal counterpart. Light penetration, light reflection, total dry matter production, and grain yields were measured to determine the effect of the leaf orientation, leaf area, and plant densities on corn production.Leaf angles of the two versions differed by 20°. Nine percent more light was intercepted by the horizontally oriented leaf type (HL). Plant populations (from 39,305 to 88,958 plants/ha) had no effect on leaf angle. High populations resulted in mutual shading which reduced the yield per plant. The mean leaf area per leaf of the HL was 17% larger than the vertically oriented leaf type (VL). Plants grown at 69,189 plants/ha had smaller leaves than those at the 49,421 population. Defoliation above the ear removed less leaf area than any of the other treatments and produced the smallest grain yield. All defoliation treatments reduced grain yield. Reflectors did not increase yield. Leaf orientation had little effect on corn production in rows spaced 76 cm apart.