Effect of Plant Population and Replant Method on Peanut Planted in Twin Rows.

Plant stand establishment is a major consideration when making planting and early season management decisions in peanut (Arachis hypogaea L.). The unpredictable and often extreme weather and the ubiquity of pathogens in the southeastern United States often contribute to poor emergence and resultant plant stands below optimum.  The objectives of this study were to determine i) the effect of plant stand on pod yield, market grade, and disease incidence in peanut seeded in a twin row pattern, (ii) if replanting is a viable option in a field with a below adequate stand and, iii) the best method for replanting peanut when an adequate stand is not achieved.  Field trials were established at two locations near Tifton, GA in both 2012 and 2013 to evaluate peanut production at four plant stands (7.4, 9.8, 12.3, and 14.8 plants m^-1) and four replant methods (no replant, destroy the original stand and replant at a full seeding rate, add a reduced rate of seed to supplement the original stand with a single row, and supplement with two additional rows).  A minimum of 12.3 plants m^-1 were needed in order to maintain yield potential, with no benefit from increasing plant stand when averaged across all site-years.  Market grade was also maximized at 12.3 plants m^-1.  Disease incidence was unaffected by plant stand. Yields were increased by supplementing the initial stand in a both a single additional row and in two additional rows by 8.3 and 6.6%, respectively.  A full replant of the original stand always resulted in lower yields when compared to the no replant and supplemental replant treatments.  While an initial stand of 12.3 plants m^-1 was needed in order to maintain yield potential, replanting via supplemental seed addition can recover lost yield at below-optimum plant stands.