Horticultural Crops: The Farmers

"Ancient" Tooling Runs Fast and Close to Yield Greens Without Weeds

Gary Gemme
South Deerfield, Massachusetts

  • 100 acres
  • soils: coarse sand to silt loam
  • wholesale fresh vegetables
  • conventional tillage with cover crops
  • limited herbicide use
  • greens (beets, chard, collard, kale, mustard, turnip), tomatoes, peppers, eggplant

Weed management highlights

Strategies: winter, summer cover crops (grains, legumes, grasses, mixes)... early precision cultivation of direct-seeded crops... on-farm greenhouse produces transplants to allow aggressive early cultivating... crop rotation... plastic mulch... preemergent herbicide on direct-seeded crops

Tools: basket weeder... belly-mount sweeps... rolling cultivator gangs... spring teeth

In 20 years of producing vegetables, Gary Gemme has invested much in weed control - much time and attention, that is, in building his management skills.

He's still perfecting the precision use of implements he bought or inherited with the farm. He minimizes hand labor through modest herbicide applications and timely use of old steel that works as well as anything else he's seen on the market.

Even paying himself $20 per hour for driving tractor, Gemme figures his mechanical weed control approach saves money compared with a heavier herbicide routine. In mostly pre-emergent applications, he applies labeled herbicides for collards, kale and peppers to give crops a jump on weeds. In all other growing situations, he depends on steel or occasional hand weeding.

Winter cover crops of rye, wheat or hairy vetch suppress weeds and protect his soil when they are green. They begin to build up soil organic matter when they are incorporated in spring. After subsoiling about 24 inches deep diagonally across the field, Gemme plows as carefully as possible to create an even, loose layer of topsoil. A soil rake (a single bar holding rigid tines) on the plow helps break up the soil, and he uses a light tandem disk as needed.

Whenever possible, he waits several weeks for the cover crop biomass to begin decomposing. He then forms 54-inch beds with sides about 4 inches tall. Furrows between them are 18 inches wide. Everything but the solanaceous crops (tomatoes, eggplant and peppers) is transplanted into the beds in three rows, 18 inches apart, centered on the bed. Tomatoes go in single rows, peppers and eggplant in double rows (staggered offset planting), all on 72-inch centers and usually with black plastic mulch.

His crop rotation for most fields is Year 1 - brassicas (collards or kale); Year 2 - solanaceous crops, beets or chard; Year 3 - a summer soil-building crop such as sorghum-Sudangrass, a fast-growing and heat-loving annual. To create a five-year rotation between solanaceous plantings, he often sublets a field to another farmer to raise a suitable crop for a year, then returns to brassicas.

'No other cultivator I've used comes close to the Buddingh Basket Weeder when you've got a small flush of weeds in seedlings,' says Gemme. Belly mounted on his Farmall Cub, he uses the tool in two ways. At the normal speed of 3 to 5 mph, he sets the wire baskets to within 3 inches of one another to cultivate young direct-seeded crops, such as onions. Gearing doubles the speed of the second set of baskets, giving them what he calls a sweeping motion that nicely mulches loose soil.

When he has taller transplants that may have a few small weeds in the row, he moves the baskets 4 inches apart and pulls back the tractor throttle. Cruising at up to 8 mph, he says the baskets do throw soil into the row - a use of the tool not intended by the manufacturer but cherished by this Massachusetts vegetable grower.

Because precision tools such as the baskets put steel quite close to crops, exact adjustment is a continuing part of tool management. 'Things are set right when the baskets clip just a couple of leaves per row. If there's no contact, you can probably get a little closer,' says Gemme. He sets the tractor's front wheels so their inside edges run against the outside edges of the bed, using the elevated soil as a no-cost guidance system. This combination works well on his flat, river bottom fields free of stones.

Gemme adds heavy wire tines ahead of the baskets to break up heavier soil for extra weed control. From his experience, he would not recommend the basket weeder for fields with rocks big enough to bend the basket wires; hard soil; frequently wet soil; crops with a wide, leafy canopy; or as primary control against grasses with rhizomes, such as nutsedge and quackgrass.

He's found the basket weeder can control weeds more than 1 inch tall if they are growing sparsely. In a thick patch of weeds, a half-inch tall is the safe maximum height. Except in especially flexible crops such as onions and garlic, he figures 9 inches is maximum crop height.

Because of their quick growth, Gemme's greens usually only need one more weed-control pass before the leaves make cultivating impossible. He uses 8-inch sweeps on a low-residue cultivator a week or two after the baskets. These are the now-standard 'medium-profile' style, which have a moderate difference between the sweep's raised center area and its wings. It's tumbling action mixes surface residue with soil more than the 'low-profile' style used in wider sweeps on the more rugged single-sweep cultivators.

During this final 'lay-by' pass, his main mission is application of 40 to 50 pounds per acre of nitrogen fertilizer next to the rows, dribbled through tubes from two tractor-mounted hoppers. The late application is the key to top yields in the nutrient-hungry crop, he's found. Because some crops also need soil hilled to prevent lodging, Gemme figures dragging the cultivators is a virtually no-cost weed-control pass. For the record, his $8 sweeps last him about three years on a four-sweep set-up that cultivates about 100 acres per year.

He adjusts the sweep tips down (angling the sweeps ends up) and increases tractor speed in order to hill as much soil as possible at the base of plants. This avalanche of loose soil retains moisture and suppresses weeds within the rows.

When weed pressure is heavy, he may make two basket passes and two runs with the sweeps. Some weeds demand follow-through beyond the current crop. For instance, Gemme mentally notes areas of high galinsoga population during spring crops. After harvest, he tills then packs the soil to create ideal conditions for the weed. He subjects the area to a fallow period during summer heat, shallow tilling it repeatedly with his tandem disk just deep enough to kill the weeds. He believes a springtooth harrow or field cultivator would do the job even better.

This practice depletes surface weed seeds and readies the area for fall planting. He can seed a commercial crop of beet greens or Swiss chard before August 15, or cover crops of hairy vetch from late August through early September or rye until mid-October. Gemme transplants - rather than direct-seeds - a spring crop into the area to maximize crop competition if the galinsoga should persist.

'I'm still working on the perfect system for controlling weeds that grow along side of plastic mulch, but I'm getting closer,' says Gemme. His tools of choice to work in the difficult area adjacent to the buried plastic sheet edges are spider gangs, such as those found on a Lilliston rolling cultivator. He can angle the soil-chewing, curving spider wheel arms to cover the entire area between the rows of plastic mulch. Their angled, slicing entry into the soil takes out weeds close to the plastic. Gemme's spider gangs are his only 'new' tools, purchased several years ago with his bed former.

He keeps a close watch on mid-season weeds, looking for signs that will tell him which tool he needs to use next. 'Every tool has its weakness, and changing the combination each pass keeps weeds on the defensive,' says Gemme. He still ends up with one hand-weeding per season of the plastic mulch. 'Some weeds always grow in the center holes next to the crop, and there's some with roots right in the buried fold of the plastic.'

He rotates 'ancient' spring-shanks in his line-up, usually using them next to the plastic to pick out strips of weeds. 'Nothing can get closer, and I can angle them if I have to,' Gemme says.

Because 'We're forever tearing cultivation tools off and re-installing other ones,' he's hoping to add a second small 'offset' tractor reserved for weed control. His current tractors are the Cub and a Farmall 200 (a 1957 version of the Super C).

As a category, offsets are general-use tractors of 10 to 30 hp. The engine section is moved to left of center and the seat rests next to the right fender. This realignment offers the driver an unobstructed view of the right half of the row area. (See 'Specialty tractors for weed control,') Used models with gearing that allows extra-slow travel in small plants are especially valuable. Gemme is looking for a cultivating tractor with vertical clearance greater than the 14 inches on his Model 200, a non-offset model.

'Too often, we finish working a patch before we get the adjustment just where we want it,' he explains. When a tool stays on a given tractor, it's field ready at a moment's notice. When there are crops to harvest, cultivate and plant before lunch, saving 15 minutes hitching time can be the difference between being in the field and just knowing you should be.

'In most of my soils, cultivating seems to stimulate plant growth,' Gemme observes. 'When my soils get sealed by rain and heat, plants don't thrive.' But in fields with coarser sand, he accepts some extra weed pressure rather than risk additional moisture loss during dry periods. He cultivates only if he's sure he can follow with irrigation once the weeds are dead.

'Weeds are getting tougher,' says Gemme. He's getting tougher on them, too, by learning their weak points and sharpening his weed-management strategies.