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Agronomic Crops > Crops Blog > Posts > Impact of Planting Date and Seeding Rate on Seedling Populations, Disease Activity, and Yield of Three Peanut Varieties in a Dryland Production System

​Seed account for up to 20% of the total variable production costs for peanut.  The impact of seeding rate of 3, 4, 6, and 8 seed per row foot as influenced by planting date on the incidence of TSW and white mold, leaf spot defoliation, and yield of commercial peanut varieties Georgia-06G, Georgia-09B, and Georgia-12Y in a dryland production system at the Wiregrass Research and Extension Center in 2014, 2015, and 2016.  Planting date but not seeding rate had the greatest impact on yield of peanut.  Yields were greater in two of three study years for the mid-April (1st Date of Planting [DOP]) than mid-May (2nd DOP)-planted peanuts, regardless of the variety.  Similar yields were obtained for Georgia-06G, Georgia-09B, and Georgia-12Y except in 2016 for the latter variety when a sharp yield decline was noted at the 2nd DOP.  The absence of a yield response to increasing seeding rates in a dryland production system was a bit of a surprise.  The lack of a variety × seeding rate interaction showed that the absence of a seeding rate response was consistent across all varieties.  In a previous Alabama study, seeding rate had a limited impact on the yield of commercial peanut varieties in an irrigated production system.  Year (i.e. rainfall) did have a sizable impact on yield.  With good rainfall through much of September, yields were averaged 5660 lb/A in 2016 as compared with drier late summer and early fall weather patterns in 2014 and 2015 when the mean yield was 2454 lb/A and 3217, respectively.


Despite consistently low TSW, leaf spot, and white mold pressure, planting date, variety, and seeding rate alone or in combination significantly impacted disease activity.  While TSW incidence was often similar across planting dates and varieties, greater disease indices were seen in the April than May planting of Georgia-09B in 2016.  Previously, incidence of this disease was also greater in April than May-planted peanuts.  The elevated level of TSW recorded at the lowest seeding rate is also consistent with the results of previous studies.  Leaf spot defoliation, which was greater in two of three years the May than April planted Georgia-06G, Georgia-09B and Georgia-12Y, also intensified slightly but significantly with increasing seeding rates in the May but not the April-planted peanuts.  When noticeable white mold development was seen in 2015, disease incidence was greater in April than May-planted Georgia-06G, Georgia-09B, and to a lesser extent Georgia-12Y varieties. Otherwise, white mold damage regardless of planting date was low in 2014 and 2016.  Overall, white mold incidence was lower in Georgia-12Y than the other two varieties.  Despite a significant year × seeding rate interaction, white mold did not intensify with rising seeding rates in any study year, which is contrary to results of previous studies in irrigated peanut.

  

Results of this and a previous Alabama study suggest that growers have some flexibility with seeding rates in dryland and irrigated production settings.  Even under drier conditions in 2014 and 2015, yield was similar across all seeding rates for all three peanut varieties.  None of the varieties screened showed a significant yield advantage in each of the three study years.  The reduction in disease damage sometime noted in Georgia-12Y did not result in a significant yield gain nor did the slightly higher levels of TSW, leaf spot, and white mold depress the yield of Georgia-09B.



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