Influence of Row Configuration on Grain Sorghum Yield on Upland and Alluvial Soils.

Cultural practices are very important in improving grain sorghum yield. The objective of this research was to evaluate the influence of row configuration and seeding rate on yield performance of grain sorghum, with and without irrigation. Field experiments were conducted in 2007 on an upland Gigger silt loam at the Macon Ridge Research Station in Winnsboro, LA and on a Mississippi River alluvial Sharkey silty clay at the Northeast Research Station (NERS) near St. Joseph, LA to evaluate the influence of row configuration and seeding rate on grain sorghum yield. Row configuration treatments consisted of single rows and twin rows (24.1-cm spacing) planted on 102-cm wide, raised beds. Treatments also included four 51-cm rows on 203-cm wide raised beds on Sharkey soil and same row configuration on a flat seedbed on Gigger soil. The trials were evaluated under non-irrigated and irrigated conditions on the clay soil. Seeding rates were 13.1, 19.7, 26.2, and 32.8 seed/m on single rows, which were equivalent to 6.6, 9.8, 13.1, and 16.4 seed/m for both twin rows and the narrow-row, wide bed treatment. In the non-irrigated Sharkey silty clay trial, yields for row configuration treatments had the following rank: twin row > single row = wide bed. Optimum seeding rates were about 26.2 seed/m for single row and 9.8 seed/m for twin row and narrow-row, wide bed treatments. Yield for row configuration treatments were similar when irrigated. On Gigger silt loam, yields were not statistically affected by row configuration; however yields tended to be highest for the 51-cm wide rows planted on a flat seedbed. Data for 2008 trials will be discussed.