Agronomic Row Crops
Standard Rotary Hoe
Overview: In clean-tilled or low-residue fields, the sharp-edged, rounded teeth on rotary hoe spokes aggressively uproot weeds in the preemergent, white-root stage. Hoes work before or after crops are up, as long as crop seed is more deeply rooted than weeds and crop tissue damage is not too severe. Rotary hoes are used for “broadcast” cultivation, i.e. lightly tilling their full width at 1" to 2" deep without regard to crop rows. Faster speed enhances surface aggressiveness but decreases penetration. Rotary hoes have a vertical entrance and surface shattering action ideal for aerating crusted soils. Increase corn seeding rate about 2 percent per intended mechanical pass to compensate for possible plant population reductions.
Design Features: Curved steel spokes radiating as a flat wheel from a hub are rotated forward by ground contact. The curvature accelerates the exit of a tooth tip from the soil, sharply kicking up soil and weeds. Rigid or folding toolbar; 18" to 21" wheels; 16 teeth per wheel; wheels on 3.5" centers. One or two wheels per arm, with most models using down-pressure springs for consistent penetration on uneven surfaces.
Cautions: worn tips greatly decrease effectiveness. Replace worn hub bearings as needed for smooth operation. Bolt attachments, rather than rivets, makes bearing replacement easier. Residue, corn rootballs, stones, sticks and plastic can plug wheels. Adding knives to cut residue or increasing spacing between wheels can improve performance in these conditions. (See next page.)
Options: Gauge wheels (recommended); extra down-pressure springs for crusted soil. (Other options for extending hoe use are described on the next page.)
Model for comparison: 21', rigid-frame
Rec. PTO HP: 75 to 90 Speed: 5 to 15 mph List price: $4,700 to $6,100
Width range (all makers/all models): 10' to 42'
Sources: 14, 18, 21, 68, 86
Farmers: Berning, Cavin, de Wilde, Fernholz, Kenagy, McKaskle, Spray
TIPS: Don't hoe bean crops from the brittle 'crook' stage to three days later. Don't expect a rotary hoe to kill green weeds - they've usually developed too deep a root system.