Submitted to: Aflatoxin Elimination Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: October 1, 2002
Publication Date: October 10, 2002
Citation: BRUNS, H.A., ABBAS, H.K. 2002. WITH-IN ROW SPACING OF MAIZE AND ITS EFFECTS ON YIELD AND MYCOTOXIN INCIDENCE. AFLATOXIN ELIMINATION WORKSHOP PROCEEDINGS. Vol. 15:104. Technical Abstract: Hybrid maize (Zea mays L.) grown in the 1950's and 1960's usually responded to plant densities over 45,000 plants ha-1 with high numbers of barren plants ha-1 and less grain per plant. Planting recommendations for modern hybrids use populations of over 62,000 plants ha-1 to achieve the high yields commonly seen today. Maize grown in the Mid South frequently uses a 101.6 cm row spacing, which is used to produce much of the cotton (Gossypium hirsutum L.) grown in the area. Six maize hybrids, two Bt and four non-GMO, were grown at Stoneville, MS in 2000 and 2001 using a 101.6 cm row spacing and plant densities of 43,000, 48,000, 54,300, 64,000 and 76,500 plants ha-1. Increasing plant density resulted in increased grain yields with no yield plateau or decline observed at 76,500 plants ha-1. Grain bulk densities varied among plant populations. However, no trend was evident. Kernel weights, ear weights, and leaf area plant-1 all declined as plant density increased. Declines in kernel and ear weights however did not affect grain yield negatively. Ears ha-1 was the most important yield component in this experiment. Leaf area index increased with increasing plant density thus negating the decline in leaf area plant-1. Leaf area index was higher in 2000 than in 2001, probably due to more rainfall. Hybrids differed in LAI, yield, grain bulk density and kernel weight. However, these differences were not correlated to one another. Aflatoxin levels were below the maximum allowable level of 30 mg MG-1. Fumonisin levels were higher in 2001 (5.0-7.9 mg kg-1) than in 2000 (0.5-1.6 mg kg-1) probably due to a more favorable environment for growth of the fungus. Modern maize can be grown in the Mid South using a population of 76,500 plants ha-1 without a decline in yield or grain quality.