By Albert Makendenge
Standing in the way of a farmer’s desired crop growth, development, yield quality and quantity are those plant species that grow right where they are not wanted. A clean and weed-free stand is what every farmer wishes for since it reduces competition for water, nutrients and sunlight. Below are a variety of methods that can be used to effectively control weeds.
Preventative weed control, to start off with, is one general technique that farmers can employ. This refers to any control method that aims to prevent weeds from being established in a cultivated crop for example the use of a certified weed free seed.
There are also cultural methods of weed control which involve maintaining field conditions that ensure that weeds are less likely to be established. Examples of cultural weed control include crop rotation and maintaining good soil fertility.
Weeds can also be controlled though mechanical means through for example tillage or mowing. This happens when farm equipment such as hoes, ploughs or cultivators are used to destroy the weeds.
Farmers can also go the biological way when looking to control weeds. This is when natural enemies of weed plants are used to control their germination or spread among established plants. One example of biological weed control is simply the use of goats to control bushes on rangelands.
Last but not least is the use of chemicals or herbicides. Common examples of chemicals used to control weeds include paraquat and atrazine. These kill the plants by causing the buildup of a toxic substance in the plant system.
Conclusively, no one method may be adequate or effective enough to deal with weeds and farmers may have to use a mix of two more techniques (known as the integrated approach) in order to get the best results.