Evaluating Plant Population and Replant Method Effects on Peanut Planted in Twin Rows

Abstract

Achieving and maintaining an adequate plant stand is a major priority when making planting and early season management decisions in peanut (Arachis hypogaea L.). Unpredictable and often extreme weather and high disease pressure in the southeastern United States can contribute to poor emergence and below-optimum plant stands. When plant stand is affected, replanting may be agronomically justified. This study was designed 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 in south Georgia in 2012 and 2013 to evaluate peanut production at four plant stands (7.4, 9.8, 12.3, and 14.8 plants/m [total plants/m across both units, or 'twins' of the twin row pattern) 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 between the original rows, and supplement with two additional rows with one between and the other next to the original rows). Replanting occurred when the stand had been established, an average of 24 days after initial planting. Pod yield at a stand of 12.3 plants/m was 6.6 and 5.8% greater than at a stand of 7.4 and 9.8 plants/ m, respectively, with no benefit from increasing plant stand beyond 12.3 plants/m. Market grade was also maximized at 12.3 plants/m. Disease incidence was unaffected by plant stand. Yield was increased by supplementing an initial stand of 9.8 plants/m in 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 yield, while grade was slightly increased in the full replant treatment.While an initial stand of 12.3 plants/m was needed in order to maintain yield potential, replanting via supplemental seed addition can recover lost yield at stands below this level.Key Words: Grade, plant stand, seed, stem rot, total sound mature kernels, tomato spotted wilt virus, TSMK, white mold.There are multiple factors that a producer must consider, normally in a very short time window, when deciding whether or not to replant a peanut field with a below-optimum plant stand. The decision whether or not to replant is a difficult one to make because while poor plant stands often result in reduced pod yield and loss of revenue (Sorensen et al., 2004;Sconyers et al., 2007;Culbreath et al., 2011), replanting may lead to an economic disadvantage if costs to replant exceed the economic benefits of added yield (Sternitzke et al., 2000).Although research is lacking on replant decisions in peanut, there are numerous studies that have reported reasons why seeds and seedlings may not survive and why plant stands may be adversely affected as a result. These stand limiting factors include soilborne pathoge...

Peanut Response to Preemergence Applications of Metribuzin

“…Similar to early season injury data, predicted values for relative stand loss were less than 8% when rates of 140 g ai/ha or less were applied. With an optimum plant stand of at least 12.3 plants/m for peanut, the level of stand reduction resulting from the 140 g ai/ha rate is not enough to warrant replanting (Sarver et al, 2017). When evaluating soybean stand following preplant applications of metribuzin, as metribuzin rate increased, soybean stand decreased (Moshier and Russ, 1981).…”