POST HARVEST MEASUREMENT AND MANAGEMENT SYSTEMS TO IMPROVE PEANUT QUALITY AND US COMPETITIVENESS
Location: Peanut Research
Title: EFFECT OF BULK HANDLING ON PEANUT SEED QUALITY
Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 2006
Publication Date: June 10, 2007
Citation: Butts, C.L., Faircloth, W.H., Lamb, M.C., Nuti, R.C., Rowland, D., Sorensen, R.B., Guerke, W.R. 2007. Effect of bulk handling on peanut seed quality. Peanut Science. 34:22-26
Interpretive Summary: Peanut is traditional planted using mechanical planters with hoppers to hold the seed. Each of these hoppers can hold about 75 lb of peanut seed. Each planter has at least hoppers that must be filled periodically. To plant at the recommended seeding rate of 100 lb/ac, approximately 195 50-lb bags of seed must be handled to plant 100 ac. A bulk seed tender is a system that is loaded at the seed facility with approximately 10,000 lb of seed. The seed tender is transported to the field where it the seed is transferred by conveyor belt or pneumatically into the seed hoppers.
This study was conducted to determine the mechanical damage to the seed using the bulk seed tenders, seed germination, and the eventual plant population after planting. The pneumatic seed tender damaged about 2% of the seed compared to 1% damaged by the belt seed tender. Both of these were higher than the 0.5% damaged seed found in the 50-lb bags. Using standardized germination tests, the bagged seed and pneumatically handled seed had the same germination rate of about 95%. Only 89% of the seed handled in the belt seed tender germinated. When these seed were planted and final plant stands were counted, approximately 75% of the seed from the bags and the belt seed tender emerged and grew into healthy plants. Only 69% of the seed planted using the pneumatic seed tender emerged and survived. A cost analysis showed that if the belt seed tender cost $7,500, then a grower who planted at least 800 ac would save money on planting costs. If the seed tender cost $5,000, the break-even acreage was reduced to 500 ac. A bulk seed tender would have to be used to plant 1000 ac if it cost $10,000.
Tests were conducted to measure the effect of using bulk seed tenders to load peanut seed into planters. Treated peanut seed were loaded into one of two types of bulk seed tenders. The first system conveyed peanut seed from a bin with an enclosed conveyor belt system to a discharge chute held over the planter seed box. The second system pneumatically conveyed peanut seed from a bin to a cyclone that reduced the seed velocity and discharged into the planter seed box. Information recorded from each transfer of peanut included the mass of seed in each container and the time required to fill the container. Two sub-samples were retained from each container to compare with the control. One sub-sample was used to evaluate mechanical damage and germination. The second sample was mixed with other samples from the same handling system, and then planted. Plant stands were evaluated periodically between 11 and 30 days after planting.
Mechanical damage caused by both bulk handling systems was significantly higher than the control. The pneumatic system damaged 2.5% of the seed and the belt system damaged 1.1%. The amount of damaged seed in the control was 0.5%. Peanut seed loaded by the belt system had an average germination rate of 89%. Seed in the control and pneumatic treatments had significantly higher germination rates of 95 and 96%, respectively. As expected, the days after planting (DAP) had a significant effect on plant emergence in the field. However, there were significant differences in emergence due to the seed handling treatment throughout the first 30 DAP. Eleven days following planting, 45% of the seed in the control treatment had emerged and was similar to the 47% emergence in the belt conveyor treatment. Only 31% of the seed handled with the pneumatic system had emerged at 11 DAP and was significantly less than the other two treatments. After 30 days, 76% of the seed from the control group had emerged and was similar to the 75% emerged from the belt treatment. The emergence of seed planted from pneumatic handling (69%) was significantly less than the control. Final plant emergence at 30 DAP was not affected by the control or the belt handling system. Economic feasibility of investing in a bulk handling system for peanuts depends on several factors including investment cost, operating cost, and cost of tote bags versus labor and paper bag cost used in traditional seed handling. Farmers must have at least 324 hectares for the bulk handling system to be equal to traditional handling.