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

Abstract

The 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.

Potential for Nitrogen Fixation in Maize Genotypes in Brazil

“…1) have indicated maximal nitrogenase activity during the flowering stage, but reasonably high activity occurs during the whole period of active growth and grain filhing. It generally is accepted that in maize the reservoir rather than the source of photosynthates is the limiting factor for dry matter production in grain (16). If so, N2 fixation would not necessarily compete with the grain for carbon substrates.…”

Changes in physiological traits associated with grain yield improvement in single-cross maize hybrids from 1930 to 1970

“…Mock (1977) found that the relationship of leaf canopies and grain yield for a group of hybrids was obscure at this plant density because of extreme barrenness. Similar studies (Ariyanayagam et al, 1974;Whigham and Woolley, 1974;Hicks and Stucker, 1972;Russell, 1972, Mason andZuber, 1976) Adequate genetic variation in ear traits for selection seems to exist in most populations (Hallauer, 1971;Obilana and Hallauer, 1974). Heritabilities, on a mean basis, for ear length and kernel depth of 76.6 and 65.3%, respec tively, were reported by Obilana and Hallauer (1974).…”

General and specific combining ability studies for leaf area in some maize inbreds in agroecological conditions of Kosovo

“…LA was determined according to the formula of Montgomery (1911): A = L×W×0.75, where L represents leaf length, W is leaf width and 0.75 is the factor used for determination of leaf area in maize. The same formula was also used by several other researchers such as Francis et al, (1969); Whigham et al, (1974) and Pearce et al, (1975). Genetic interpretations and analyses of similar experiments can be found in numerous papers such as Hayman (1954) and Griffing (1956).…”