The recent trend toward restricting herbicide use has produced interest in alternative and integrated weed control strategies that include cultivation. As a result, newly-developed implements are now available to vegetable growers, but the potential uses of these tools for numerous vegetable crops can be confusing. This publication describes some of these tools and their advantages and disadvantages, based on four years of research at Cornell University. It should be noted, however, that this is not a complete list; several other designs are available that were not tested in these trials.
Flex-tine harrows are used broadcast, both over and between the crop rows. They are most efficient when weeds are in the white-thread or cotyledon development stage. In direct-seeded crops, such as snap beans or sweet corn, flex-tine implements are used preemergence. Tines pass above the planted seed. Harrowing can be repeated postemergence for control of newly germinated weeds, but only when the crop is well-rooted. Cultivation intensity can be modified to minimize crop damage. Guide wheels and tine intensity regulate harrowing depth.
Advantages
Disadvantages
The Einbock harrow (Fig.1) has floating beds of tines mounted on a tool bar. Cultivation on uneven ground or hillsides is possible with the floating bed system. Tines can be lifted above the crop row; however, tine intensity is modified on a bed-by-bed basis with a single adjustment.
The Lely harrow (Fig.2) is a lightweight tool with very flexible tines that vibrate to rip weeds from the soil. The implement's light weight can be a "cure or curse"--the harrow is easily maneuvered with a low-horsepower tractor, but its cultivation efficiency is reduced on hard-packed or crusted soils. Tine intensity is modified on a tine-by-tine basis.
Rabe Werk manufactures two harrows; on having flat tines (Fig.3) and one with round tines (Fig.4). The flat-tined harrow is very aggressive and effectively breaks crusted soils. Tines are modified individually in three intensities: high, low, and tines lifted above the crop rows. The round-tined implement is similar to the Einbock harrow and has floating beds of tines.
The brush hoe has PTO-driven plastic bristles that rotate on a horizontal plane, aggressively ripping weeds from the soil. (Fig.5) Shields, hung above the soil surface, protect the crop from the rotating brushes but allow soil to move into the crop row. Because the tool is very aggressive and precise, and additional operator (on the rear seat) is required to steer the shields over the crop row. Cultivation depth is modified with guide wheels and the three-point hitch attachment. Several row spacings and brush configurations are available.
Advantages
Disadvantages
The finger weeder is designed specifically for in-row weed control (Fig.6). The tool has three pairs of ground-driven rotating fingers: two pairs in the front push soil and uprooted weeds away from the crop row; while the third pair pushes soil back into the row, covering weeds that were missed by the other fingers. The weeder is most effective when fingers pass very close to the crop row; therefore, precise cultivation and slow driving speeds are important. The finger weeder is most effective on small-acreage, high-value crops.
Advantages
Disadvantages
The torsion weeder is mounted on an existing inter-row cultivator for improved in-row weed control (Fig.7). This simple tool has spring-loaded steel rods on each side of the crop row for undercutting small weeds. The width of the uncultivated strip is easily adjusted for each crop and development stage.
Advantages
The best weed control strategy often integrates several management strategies, which may include mechanical control Two ways to reduce herbicide use while minimizing the risk of poor weed control and reduced yields are to combine cultivation with banded herbicides or with some of the new postemergence herbicides (e.g. Reflex and Basagran for snap beans), used on an as-needed basis. Research in sweet corn, for example, has shown that yields were equivalent when a single cultivation was combined with Dual and Atrazine banded over the crop row and when the same herbicides were applied broadcast without cultivation, even in wet years. Results were similar in potato studies, where the combination of banded herbicides and a single hilling six weeks after planting produced yields equivalent to broadcast herbicides plus hilling.
| Brush Hoe |
Baertschi FOBRO |
| Finger Weeder |
Buddingh Weeder Co., |
| Torsion Weeder |
Bezzerides Brothers, Inc. |
| Flex-Tine Harrows | Einbock |
Landaschinenbau G.E.S. m.b.h. & Co. |
|
Canadian Distributor |
||
| Rabe Werk |
Machinerie Agricole St. Cesaire, Inc. |
|
| Lely |
Lely Corporation |
More MECHANICAL WEEDER photos. Finger Weeder Tine Rake Weeder Basket Weeder
Reprinted from IPM Fact Sheet 102FSNCT, a Cornell Cooperative Extension publication.
Jed Colquhoua and Robin Bellinder, Department of Fruit and Vegetable Science, College of Agriculture and Life Sciences, Cornell