Principles of weed control

Dear readers, in one of the previous articles some aspects related to weed control methods were discussed. But it is necessary to consider that an integral weed program or integrated weed or weed control system is mainly based on knowing the agroecology and dynamics of the plants to implement an efficient management, if possible using all the techniques mentioned above for an effective combat and control, reducing the economic damage below the threshold that can affect the productivity of agricultural systems.

It should be remembered that plant species considered weeds have a high adaptability in agricultural ecosystems, developing in adverse habitats where crops do not thrive, among the abilities or mechanisms that these species present are the latency of their seeds, high regenerative and reproductive capacity, among others. In addition to the interspecific competition they have in agricultural ecosystems for light, water, space, nutrients, all these aspects make weeds remain consistently in ecosystems. Therefore, sometimes a single control method does not guarantee the reduction of their presence in crops, and it is there where different methods that disrupt the life cycle of the weeds must be applied to reduce their vigor.

1. To know the ecological and morphological characteristics of the plant: this aspect is of great interest, we call it a weed inventory, since, for this, a previous diagnosis of the cultivated areas must be made and with the written and photographic record, many records of these species can be used, such as the weed data sheets that we have published in hive. With this type of information, it is possible to know the characteristics of the weeds, such as, for example, there are species of asexual reproduction (rhizomes) and sexual reproduction (seeds).

The aforementioned characteristics allow making the right decisions regarding their control, such as, For example, for species that reproduce by rhizomes that develop below the soil surface, it would not be enough to eradicate the upper part of the plant, because its reproductive part would remain dormant to re-emerge, in this case the ideal would be to remove the soil surface to extract the rhizomes and apply herbicides, there we would be applying a mechanical and chemical method.

On the other hand, if we identify a plant with high seed production in its inflorescence, we would seek to apply a methodology to avoid spreading all the seeds on the surface, in the southern area of Lake Maracaibo Venezuela, to control the big-headed Paspalum virgatum in some livestock production systems tend to place a bag in its inflorescence to prevent the seeds from spreading and to extract the root plant, it is a very expensive method because it requires a lot of labor, but has given good results.

2. Appropriate agronomic management: this principle consists of efficiently managing the sown crop, for example, if we are talking about pastures, we must cultivate species that are adapted to the ecological conditions of the area, in this way it will have a good development and will not be greatly affected by competition from weeds, in addition to this, essential agronomic practices such as fertilization must be applied to provide the essential nutrients for its development.

It is also important to know the dynamics or behavior of the plant in the cultivated area, for example, there are species that are indicators of soil moisture, for control before applying any chemical product is to perform drainage that affects their habitat and then apply another type of complementary control. The soil can also be prepared and before planting wait for the seedlings to emerge to apply a chemical control and then planting can be done.

3. Control weed infestation: This principle consists of avoiding the generation of infestation foci in cultivated areas, for example, the movement of machinery or implements from one farm to another can generate the dissemination of species from one place to another, in the same way through animals, since many weed seeds use the digestive tract of animals as a means to break dormancy, so it is important to place animals in quarantine when moving from one place to another to expel the contents they have in the digestive tract in controlled places.

It is evident that different control methods can be applied simultaneously in the production units, since, as mentioned at the beginning, one single method is sometimes not enough, let's know the species present to implement the most correct methods that will be the most economical if weed control is achieved. Weed control can be very costly, so we must know in depth the dynamics of these plants to apply integrated management.