Deere 7720's Make Great Crop Sprayers

Deere 7720's Make Great Crop Sprayers COMBINES Modifications 12-5-1 A pair of working Deere 7720 combines equipped with homemade 80-ft. "wet-type" booms and front-mounted 500 gal. tanks make great crop sprayers for Wiley Juedeman, Geraldine, Mont. Juedeman, who uses his combines to apply herbicides to fallow ground and standing wheat, got the idea two years ago when he switched to reduced tillage. "I was able to build each of these combine-mounted sprayers for about $4,500 each. They have eliminated the need to buy expensive pull-type sprayers or to hire custom aerial spraying at $2.50 per acre. What's more, the combine cab provides air conditioned comfort and a great view of the boom." The 80-ft. booms, made of 6 in. dia. steel tubing, are supported by a pair of walking beams with castor wheels and are braced with 2 by 2 in. square tubing. Each sprayer has four 20-ft. sections independently controlled by solenoid valves. Boom pressure is 24 psi, with nozzles set on 20-in. spacings. Spray tanks mount between and just ahead of the large front drive wheels. Each tank is carried in a tank support cradle frame. Juedeman designed his first model with a plastic tank, attaching its tank support cradle frame directly to the upper end of the feederhouse. Hookup requires removal of the feederhouse, a time-consuming job. To solve that problem, on the second model Juedeman built quick-hitch adaptor brackets. "To remove the tank I simply pull two pins, unhook the sprayer, set the tank on the ground and back away from it," he says, noting that both combines are still used for harvesting. The quick-hitch brackets move the sprayer forward, making the combine"front heavy". To keep the tank's weight as close as possible to the front axle, Juedeman had a stainless steel tank custom-built that's only 3 ft. in diameter but 10 ft. long. To add weight to the rear axle, he filled the combine's rear tires with chloride. "We spray at 7 mph, applying 5 gallons per acre. "Tipping hasn't been a problem," he says. Raising and lowering of the boom is done with hydraulic cylinders which normally control the cutting platform and feederhouse. Swivel mechanisms on the tank support cradle frames allow the booms to flex on uneven ground. To circulate spray solution and to adjust spray pressure, Juedeman engages the combine separator drive and the hydraulic driven pump which ordinarily drives the combine reel. The combine's electromagnetic header stop switch provides instant pump control. Juedeman, who sprays in 6-in. tall wheat, says the combine tires do little damage to the crop. "In this year's drouth-stunted crop, the combines left noticeable tracks that you still could see at harvest. However, in normal growing conditions, you can't see the tracks after a few weeks." To transport the rigs, Juedeman pulls a pin and manually swings the outside boom sections forward. This winter he plans to build another combine-mounted sprayer with spring-loaded pins in the boom. "Pulling the pins will result in both outside boom sections automatically snapping forward into position," he notes. Contact: FARM SHOW Followup, Wiley Juedeman, Box 276, Geraldine, Mont. 59446 (ph 406 737-4461).

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