Growers are only limited by their imaginations in implementing non-toxic weed control methods on their farm. The most obvious way is to take the chemical farming approach and find an organically approved material to do the killing. Very strong vinegar has been the most marketed material. The important factor in vinegar formulas is to have a surfactant that strips away any waxy protective coating on the plant surface and that allows the desiccation or drying out of the plant. Salt provides the same mode of action and may be included in the formula.
Flame is an even more modern and harsher approach. The mechanical approach is the most widely used by growers around the world. Cultivators are a modern version of hoe, hoe, hoe or hand pulling. Rotary hoes or spiked harrows are special adaptations of the cultivation approach. Using plastic films, whether degradable or not, is a form of smothering that is similar to mulching by any material. Here the weed is denied sunlight to prevent nature’s germination response.
Repeated cuttings in a fallow situation of a perennial weed may weaken a plant over time by using up any stored energy. Every attempt is also made to prevent the reseeding of an offending species. Treating isolated patches is worth the effort to keep them from spreading. If a field is overwhelmed to a point of not having an economic crop worth harvesting, be sure to take the whole field down before the offending weeds go to seed. Keep in mind that there are seeds in your fields that may have been there for years. Just lime or activate the calcium in your soil and watch clover appear in uncultivated ground that you haven’t spread clover on since you bought the farm.