The problem with weeds is that they have a negative impact on bottom line of the farming business. Quite often growers don't have enough deeper knowledge to understand just how much it affects yields, quality and efficiency of the whole farm. Competition All plants exert some type of competition on each [...]
After applying a herbicide to a field with weeds, the herbicide needs to follow a certain path in order for it to be effective. Firstly it has to be absorbed through the leaf cuticle Secondly the herbicide must be trans-located through the plant in order to have any effect on [...]
The selection of herbicides is not always based on the weed that it should control. There are many conditions in the environment that will influence the grower or user’s decision to use a specific herbicide. For instance, the length that the herbicide will be active in the soil will be [...]
Once the active ingredient of the herbicide has been developed it has to be presented to the user in a format which will be both economical and effective. Many companies provide the growers with a herbicide in different formulations depending on the application. The different formulations are used in order [...]
Characteristics of each chemical group differs from each other so it is important to know to what group a herbicide belongs before applying it to a plant. Active ingredient will also provide an indication of lead time before a crop can he safely harvested. There are so many ways of [...]
General classification of weeds Most farmers use a different method of classifying weeds since it is easier to understand and separate each weed from another in order to control them. Classification according to growth season length Annuals: These weeds complete their life-cycle in one year. Due to the abundance of dormant [...]
Biology of weeds is important since it covers all aspects of their establishment, growth and reproduction. All climatic factors have a significant effect on biological processes. A good knowledge of the biology of weeds will ensure that the grower and researcher will be able to apply technology correctly to control any [...]
As the pressure increases to develop safer and more economical herbicides, the Government is forced to either withdraw or restrict some of the older chemicals. Table 3 provides a list of the restricted and banned herbicides used in South Africa. It is important to have this list handy so that anybody [...]
Application and Herbicide drift If pressure is used to apply herbicides, there will always be some herbicide drift through the air. If there is no commercial crop in the vicinity, spray drift will have no effect, however, when weeds have to be controlled between rows of a commercial crop, any spray [...]
It sounds strange to think that weeds do have advantages. This way of thinking is made difficult by our perception and definition that weeds do not have any use. Plants classified as weeds are often removed without evaluating the environment first. By removing one type of weed in an area does [...]
