Effect of plant population and row width on the performance of soybeans

The effect of genotype, row width and plant population on the growth of soybeans (Glycine max (L) Merr.) was investigated in 1977 on a Sequatchie Loam soil at the Plant Science Farm, Knoxville, Tennessee. Six genotypes, three row widths, and three plant populations were used. Genotype had the greatest influence on plant height. The final plant heights of the two tall genotypes were 14 cm greater than the two mid-tall genotypes, and 36 cm greater than the two short genotypes. The tallest plants of each genotype were at the highest plant population. The shortest plants of each genotype were at the lowest plant population in 50 cm row widths. Differences in plant height within genotypes were observed at 5 percent level of probability. All six genotypes showed an increase in plant height with higher plant population and narrower row width. Lee 74 and Forrest were the most susceptible genotypes to lodging. Essex, M-Sk and M6-103 were the least. Lodging was increased as row width decreased and plant population increased. There was no major difference in seed size at the different combinations of row width and plant population studied. Essex had the largest seed and M-Sk and M6-103 the smallest. Forrest and M-Sk observed a direct relationship between plant population and seed size. Yield of Forrest and Essex were not significantly affected by either row width or plant population. In general, higher yield for each genotype was obtained at the closest row width and high plant population.