Effect of Plant-spacing and Water-supply on Growth and Water Use of Sweet Corn Plants

  Objective  Effects of plant-spacing and water-supply on the biomass, yield, and water use efficiency of sweet corn plants were studied for better irrigation management.

  Method  A field experiment including varied plant-spacing (i.e., 20, 30, and 40 cm) and amount of water supplied for the irrigation (i.e., 215, 265, and 365 m³·hm⁻²) for sweet corn cultivation was conducted to determine their effects on the biomass, yield, and water use efficiency of the plants.

  Result   The spacing between individual plants significantly affected the biomass accumulation of each plant; the water-supply for the irrigation significantly altered the biomass allocation on a plant; and the interactions between the plant-spacing and irrigation significantly modified the allocation as well as the distribution of biomass on a plant. (1) As the spacing increased, the biomass increased significantly to reach a maximum at 40 cm separation between two plants. When that was combined with water-supply, both quantity and proportion of stem biomass on a plant significantly increased; and the weight of fresh ears became the largest and the principal component comprehensive score greatest on a plant at the irrigation that provided 365 m³·hm⁻² of water. (2) The allometric constants of leaf and stem/aboveground biomass rose as the spacing and water-supply decreased and followed by an increase, while that of ear/aboveground biomass being the opposite. Those of ear/aboveground biomass peaked at the combined 30 cm for the spacing and 265 m³·hm⁻² for the water-supply. Meanwhile, the constants of leaf and stem/aboveground biomass lowered but that of ear/aboveground biomass maxed. (3) Increasing spacing significantly decreased the sweet corn population yield. However, the irrigation did not exert significant effect on either yield or water use efficiency as they were the highest at the 265 m³·hm⁻²×20 cm combination.

  Conclusion  The biomass of a sweet corn plant peaked with the combined treatments of 365 m³·hm⁻² on water-supply and 40 cm on plant-spacing. But the greatest population yield and water use efficiency were observed under the combination of 265 m³·hm⁻²×20 cm. The information would lead to an improved irrigation operation for a high yield and high efficiency sweet corn production in arid hot valley and similar areas.