Evaluation of Seeding Depth and Planter Downforce for Planting Cotton in Diverse Field Conditions

Higher seed costs incurred in cotton production have challenged growers to optimize planter performance for ensuring successful stand establishment, especially in adverse field conditions.  A study was conducted to evaluate the effect of different planter depth and downforce settings on crop emergence and yield for cotton planted in diverse field conditions. A field split into three blocks of equal area was used to simulate three different at-plant soil moisture conditions (dry, nominal and wet) by applying 0.0, 0.5 and 1.0 inches of irrigation to each block 24 hours prior to planting. Planter settings included three seeding depths of 0.5, 1.0 and 1.5 inches each paired with three downforces of no additional downforce, 100 and 200 lbs. to represent seed placement scenarios that normally occur in grower fields while planting cotton. Two cotton cultivars differing in seed size and vigor (a small seeded low vigor and a large seeded high vigor) were planted using the selected treatments in each block. Stand counts were performed at one, two, and three weeks after planting from the middle two crop rows in 10-feet sections. Yield data was recorded by harvesting the middle two rows using a two-row cotton picker. Results indicated that crop emergence and yield differed significantly for the two cotton cultivars. For each cultivar, soil moisture at planting and planting depth affected crop emergence and yield. Cotton planted at the 0.5 inch depth in dry soil conditions exhibited reduced crop emergence and yield due to inadequate seed placement. A depth*downforce interaction existed in large seeded cultivar where crop emergence was decreased significantly for cotton planted at 1.5 seeding depth and 100 lbs. of downforce. Overall results suggested 1.0 inch as an optimal seeding depth for planting cotton in most field conditions irrespective of the planter downforce, soil moisture conditions and cultivar selection.