This FAR Arable Extra is the first in a series of three that will discuss alternative methods of controlling weeds. It examines the role of mechanical weeding and how it can be integrated into a cropping system, either as direct substitute for, or alongside herbicide applications
Key points
Modern mechanical weeding work rates are on par with other field operations, such as spraying. There are two main approaches: spring tine harrows that weed the whole field surface, and interrow hoes, that only weed the interrow area, but with a much more aggressive action than harrows
• Spring tine harrows can achieve weed control on par with herbicides in robust crops such as cereals and beans. They are more effective against broad-leaf weeds than grasses and don’t work so well in coarse or stony soils
• Interrow hoes are better suited to more delicate crops, e.g. vegetable seed, and more challenging soils. They kill more weeds in the interrow, but they need guidance systems, such as RTK GPS, or computer vision to keep them on line
• Both spring tine harrows and interrow hoes can be substituted for herbicide applications and they can also be used synergistically with herbicides, e.g. band spraying the crop row and mechanically weeding the interrow