Effect of plant density on growth and yield of extremely late-planted korean sweet corn hybrids (Zea mays L.) for fresh market

Abstract

Sweet corn has a short growing period of 80 to 90 days in Korea, which allows famers to grow this crop using various cropping systems. This objective of this study was to find the optimum plant density for Korean sweet corn (se) hybrids ‘Godangok’ and ‘Guseulok’ when they were grown as the second crop. Plant densities were 5,710, 6,670, and 8,000 plants 10a-1 and planting dates were 20 July and 30 July, 2013. There was no interactive effect between plant density and hybrid for all the analyzed parameters in this study. Increasing plant density up to 8,000 plants 10a-1 led to no significant gain in marketable ear yield. Although the total number of ears was increased about 21 c 33% at the highest plant density than at lower densities, e.g., 6,670 or 5,710 plants 10a-1, the percentage of marketable ear number and individual ear weight decreased with increasing plant density. Individual ear weight of marketable ears was significantly greater, e.g., by 8 c 13%, at 5,710 plants 10a-1 and 6,670 plants 10a-1 than at 8,000 plants 10a-1. Similar results were obtained for ear length and width and filled length under the given plant densities, which indicated that increasing plant density may decrease individual ear fresh weight and ear size with good tip fill. Increasing plant density up to 8,000 plants 10a-1 caused the lowest harvest index, which resulted in little gain in fresh ear yield compared to the lower plant densities of 5,710 and 6,670 plants 10a-1. These results indicated that the optimum plant density for those sweet corn hybrids planted in July would be between 5,700 and 6,700 plants 10a-1 in terms of marketable ear yield and quality of marketable ears.