Influence of Row Spacing, Seeding Rates and Herbicide Systems on the Competitiveness and Yield of Peanuts1

Peanuts (Arachis hypogaea L. ‘Florunner’), infested with sicklepod (Cassia obtusifolia L.) were grown during 1977 and 1978 in 20.3-, 40.6- and 81.2-cm row widths (on Dothan sandy loam and on Greenville sandy clay loam). The crop was maintained weed-free for 0, 2, or 5 weeks or for the entire growing season. Three herbicidal systems with various intensities were utilized. In 1978, reduced and regular rates of in-row crop seeding were compared. Weed-free maintenance for 5 weeks generally produced yields of peanuts equivalent to those obtained with continuous weeding. Sicklepod green weights were reduced by 28 and 53% in peanuts with row spacings of 40.6 and 20.3 cm, respectively, as compared to standard 81.2 cm spaced rows. Peanuts in close-row patterns yielded about 14% higher than the conventional 81.2 cm row spacing when averaged for all studies. Adjustments of the in-row seeding rate to produce a more normal seed-drop per hectare reduced the yield of peanuts only 1 to 3% and, therefore, did not negate the increased yields produced with close-row spacings.