Effect of Cotton Seed Size and Seeding Rate on Cotton Growth, Development and Yield

Cotton (Gossypium hirsutum) has seen a reduction in seed size from what was grown sixty years ago, due to trying to select for cotton that produces more lint per boll and lint per acre. Seed sizes that are considered large today would have been considered small sixty years ago.

In recent years some varieties have seen a reduction in seed size which can be concerning due to a smaller seed having less energy to emerge through the soil. Changing seeding rates can be a way to combat the low energy of a small seed. Therefore, the objective of this research is to investigate the effects that seed size and seeding rates have on cotton growth and total seed cotton yield.

A field experiment was conducted during the 2019 growing season across 3 locations: Starkville, and Brooksville, Mississippi and Jackson, Tennessee. NexGen 3406 and Deltapine 1646 were planted with three different seed sizes and three different seeding rates. Stand counts and vigor ratings were recorded at 14 DAP, 21 DAP, and 28 DAP and biomass was of 5 cotton plants per plot was recorded at the four to six leaf growth stage. Additionally, height, node, and nodes above white flower were recorded at first bloom; along with height, node, and node above the uppermost cracked boll being recorded prior to defoliation. The objective of this research is to have a better understanding of the effects that seed size and seeding rates have on the growth and development of cotton.