Abstract
Moisture removal is a major function of the peanut (Arachis hypogaea L.) curing process. While commercial peanut production in the United States has become largely mechanized, peanut breeders must often resort to the stackpole method of curing. This two year study evaluates the effects of alternative curing methods on seed quality of experimental peanuts. Three cultivars were harvested at two maturities, and after 0, 1 or 2 days exposure in inverted windrows, fruit from each treatment were then cured on stackpoles or in circulating air ovens at 38°, 54° or 66°C. Analyses were made on weight/seed and percentages of moisture, shelling, shrivels. germination, and extra large kernels.
While year of production affected seed weight and germination, harvest date within years did not affect the characteristics studied. Days in the windrow affected moisture content. Drying temperatures affected shelling, shrivels and germination percentages.
Harvesting a week earlier than optimum resulted in more shriveled seed but better germination. This indicates that it may be advantageous to dig a crop used for seed earlier than that dug for edible use.
The % shriveled seed increased somewhat with increased drying temperatures. Stack curing had the lowest % of shriveled seed. Peanuts that were not placed in windrows had heavier seed if stack-cured than if oven-dried, indicating that the seeds continue to mature while attached to the vine.
Seed from pods cured in ovens at temperatures below 54°C, especially when left in windrows a day or more, germinated as well or better than those stack-cured. At high oven temperatures, germination increased with number of days in windrows indicating that viability is impaired at high temperatures when moisture content is high.
The results indicate that peanut researchers could improve their harvesting efficiency by picking from the windrow and utilizing mechanical dryers adjusted to a somewhat higher temperature than that recommended for edible peanuts. The stackpole method results in high quality seed with less risk of loss than from windrow curing.
Author notes
1Contribution of the Florida Agricultural Experiment Stations as Journal Series No. 5622.