The objective of this work was to evaluate the effect of narrow row spacing on leaf area index, leaf senescence, interception of photossintetically active radiation and on grain yield of two corn hybrids grown in three management systems. Three experiments in randomized block design, in 2x2x2 factorial array, were carried out in Eldorado do Sul, RS, Brazil. In each experiment, treatments consisted of 0.4 and 0.8 m row spacing; erect and decumbent leaves hybrids; and two plant densities (5 and 6.6 plants m-2; 6.2 and 8.3 plants m-2; and 6.5 and 8 plants m-2, for medium, high and very high management levels, respectively). Levels of fertilizer and water availability varied according to the management system. Leaf area index and interception of photossintetically active radiation change with row spacing, but depended on the phenological stages, plant density, leaf arquitecture and management system. Leaf senescence was not affected by row spacing, regardless of management systems, plant density and hybrid. Narrow row spacing increased grain yield only in the very high management system. Canopy traits did not follow the grain yield performance.
Zea mays; plant density; hybrids; leaf area index; irrigation; fertilizer levels
