Weed control, organic methods

Application methods Usually as water spray or in liquid fertilizers applied preemergence, but also may be applied preplant or postemergence. Rates of 2-4 pounds/acre (2.24-4.48 kg/ha) are effective for most situations higher rates are used for nonselective weed control, and on high organic soils... 

Providing weed suppression through the use of allelopathic cover crops is an important method of weed control in organic farming and it is one of the best possibilities of allelopathy application (Sullivan 2003a). Besides, growing of cover... 

A weed can be an annual, a biennial, an herbaceous or shrubby perennial, or even a tree species. This chapter introduces you to the way weeds work—how and why they are so efficient—and the range of organic methods you can employ to clear weeds and keep them under control. It is useful to be able to identify common garden weeds, especially perennials (see pp.80-81). Knowing how they reproduce, spread, and survive adverse conditions can help you to develop an effective control strategy. 

Radies, L. and Sz kelyne Bognar, E. 2002. Comparison of different mulching methods for weed control in organic green bean and tomato. In Cloutier, D.C. (ed.) Proceedings of the 5th EWRS Workshop on Physical and Cultural Weed Control. Scuola Superiore Sant Anna di studi universitari e di perfezionamento, Pisa, Italy. 11-13 March 2002. European Weed Research Society, Pisa. pp. 192-204. 

There are no approved chemical methods to control weeds in organic crops. Growers have to rely primarily on preventive or physical measures to maintain weed control. These measures include rotation, timing of cultivation, undersowing and the use of mulches. Physical methods may also be used and these include hand weeding, the use of mechanical techniques such as brush hoes and thermal destruction. 

Weed control has to depend to a greater extent on cultivation methods and a greater understanding of weed species is needed than in circumstances where they can simply be sprayed out of existence. Pests and diseases may also be affected by cultivation methods but interactions with other organisms are of enormous importance. 

The control of weeds with herbicides is standard practice on most farms nevertheless, it is worth remembering that other htrsbandry methods play an important part, especially with the increase in herbicide resistance problems and the hmited introduction of new products. Non-chemical methods of weed control are the only ones available to organic farmers. 

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