Leaf emergence, tillering, plant growth, and yield in response to plant density in a high-yielding aerobic rice crop

The last upper leaves of the main stem appeared faster at higher plant density, thus increase plant density was not the cause for the slower leaf appearance in aerobic than in flooded crops. Plants at higher plant density also had earlier panicle initiation, earlier earing, and 0.8 leaf less than plants at low density. The number of outgrowing tillers was linked to the number of leaves on the main stem by a variety-specific relationship that is independent from plant density and water management. Tiller density was regulated by the cessation of the outgrowth of tillers triggered by the onset of stem elongation at 20-cm plant distance and occurred earlier at shorter distances probably in response to the high root density. Grain yields were significantly higher at higher plant density (6-cm and 10-cm plant distances) and correlated with a higher tiller density. Thus for aerobic crops, seedling density higher than 50 plants m−2 remains the way to get high yields for the type of variety used in this study.