Row spacing and population density in grain sorghum — A simple analysis

Abstract

A simple analysis is described by which yields of grain sorghum, Sorghum bicolor L. Moench.), at different row spacings may be compared over a range of yield levels. Yield at one row spacing is plotted against yield at alternative row spacings. Then from regression analysis it is possible to compare row spacing effects and to determine the best row spacing at any given yield level. strated the relationship between row spacing and environmental conditions. Since a single curve fitted the data from differing sources, the relationship may have general application. Under conditions producing yields exceeding 3700 kg ha −1, the optimum row spacing is 25 cm; for yields of 3100–3700 kg ha −1 the optimum is 50 cm; for yields of 1100–3100 kg ha −1 the optimum is 75 cm; while for yields of < 1100 kg ha −1 the optimum is 200 cm. If weeds are present, the row spacing relationship requires modification in favour of closer rows. Using the same form of analysis, comparisons of different plant population densities were inconclusive.