|Meredith Jr, William|
Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 17, 2009
Publication Date: July 15, 2009
Citation: Pettigrew, W.T., Meredith Jr, W.R. 2009. Seed Quality and Plant Date Effects on Cotton Lint Yield Components, and Fiber Quality. Journal of Cotton Science. 13:11-24 Interpretive Summary: Inputs for producing all row crops have increased dramatically during the past few years. One of these high input costs for cotton producers is the cost of seed due to the technology fees assessed for the desired trangenic traits contained in the seeds. Because of theses higher seed costs, producers have begun reducing seeding rates to minimize this expense. However, reducing seeding rates can compromise profitability if insufficient stand establishment occurs due to the use of poor quality seed. This study investigated how increasing the seeding rate of poor quality cotton seed lots or blending high and low quality seed lots together affected stand establishment, plant growth and development, yield production and fiber quality. When seeding rates were adjusted to ensure similar germination and emergence, no meaningful differences were detected in growth and development, yield production or fiber quality. Blending seed lots together also produced similar growth and yield results to the high quality seed lots so long as the seeding rate was high enough to account for the percent of low quality seed in the blend, therefore resulting in similar numbers of emerged plants. This research demonstrates that yields and fiber quality can be maintained when low quality seed has to be used by increasing the seeding rate to insure that adequate stand establishment still occurs. These results will be especially informative to producers and extension personnel when poor weather conditions during the prior year’s harvest season resulted in a reduced overall quality of seed available for planting.
Technical Abstract: Having to use poorer quality cotton seed, due to unfavorable growing conditions in seed production areas, complicates planting decisions for producers, particularly when higher priced transgenic cultivars are involved. This study investigated how varying planting dates and genetic backgrounds affected the development, lint yield production and fiber quality for seed lots of varying quality or seed size. Twelve different seed lots of varying cultivars, seed germinations rates, and seed sizes were planted at either an early April or early May planting date during the years 2002 through 2004. Seeding rate adjustments were made based upon the germination rate of the seed lots and seedling survival expectations for the two planting dates. Seedling emergence counts, dry matter partitioning, lint yield and yield components, and fiber quality data were collected on the plots each growing season. Although early planting reduced seedling emergence by 16%, lint yield was increased 14%. Planting seed lots of varying germination rates for individual cultivars had essentially no impact on lint yield production and few affects on dry matter production or fiber quality. The larger seed size seed lot of PM 1218BR resulted in 17% more seedlings emerging than the small seed size lot, and that also carried over to produce 7% more lint yield for the large size seed lot. The overt negative consequences from inadequate stand establishment on lint yield production by using poor quality seed can mostly be avoided by adjusting the seeding rate to account for poorer germination rates or the poor emergence conditions associated with of the early planting.