Over the next few weeks, peanut harvest will be in full swing across most of the state. Along with proper timing consideration for digging peanuts, proper setup and operation of peanut harvest equipment is also an important consideration to minimize harvest losses and to ensure peak equipment performance and efficiency during harvest. Here are few considerations for growers to keep in mind when digging peanuts to prevent any mechanically induced yield losses due to improper digger setup and/or operation:
- Using an RTK Guidance system/Auto-Steer on the tractor while digging peanut helps in maintaining the digger path directly over the row center or over the planting path and results in approximately 10% reduction in yield losses compared to when digging peanuts with a tractor without an auto-steer system.
- Before beginning harvest and making any adjustments specific to the harvest conditions, inspect the digger carefully for any broken, bent or missing parts as well as the sharpness of the blades. Dull blades fail to cut the tap root resulting in dragging roots or dislodging pods from the plant.
- Adjust the digging angle (and therefore depth) by adjusting the length of the top link on the digger. Digger blades should be set at a slight forward pitch and at the depth where they cut the tap root just below the pod zone. Both an excessively shallower and deeper depth of the digger blade can result in significant digging losses.
- Blade angle/depth is also dependent on soil type and texture. Any considerable change in soil type within or among the fields will also require a change in blade angle/depth adjustments as clay soils usually need a more aggressive angle whereas sandy soils require a less aggressive blade angle.
- Digging speed should be optimized based on the prevalent in-field conditions at harvest. Generally, the optimal ground speed for digging peanuts is between 2 and 3 mph. Speeds above 3 mph can result in an increase in digging losses and therefore should be avoided.
- Set the conveyor speed to match the forward travel speed of the tractor while digging peanuts. Conveyor speeds slower or faster than the tractor speed can both result in increased pod losses.
- The conveyor depth should also be adjusted where it picks up vines with its teeth just clearing the soil. Additionally, if needed, adjust the knocker wheels up or down to regulate the amount of shaking where is enough to remove the soil from the vines.
Remember, properly dug and inverted peanut plants will form a uniform, fluffy, well-aerated windrow with very few pods touching the soil so make sure to keep a close eye on the digger operation in the field and adjust settings accordingly as and when needed.
Peanut Digger and Combine Efficiency, UGA Extension, Bulletin 1087
Guide for Peanut Digger Setup and Operation, Clemson Cooperative Extension