Hanks Saisai
As the current rainy season progresses, good rainfall has been recorded in almost all parts of the country. As a result, crop farmers are witnessing a productive crop production season with noteworthy growth of maize, sorghum and pearl millet (mahangu).
However, amidst the pleasant growth, a crucial aspect of production to undertake is weeding in their crop fields.
By definition, a weed is an unwanted plant that grows among desirable crops that a farmer has planted.
Weeds have negative effects, as they compete with crops for water, nutrients and sunlight.
Furthermore, weeds can significantly lower the quality of crops by contaminating seeds, while some weeds can be alternative hosts for pests and disease-causing organisms.
However, when undertaking weed control – the removal of weeds from the field or garden on which the desired crop is growing, it is essential to ensure that economical and environmentally friendly techniques are used within a reasonable period to allow the main crop to grow well.
Weed control is important for several reasons.
Firstly, it reduces competition for water, which is vital for growing crops.
Secondly, weed control enables crops to have access to more sunlight, which is absorbed by the leaves for chlorophyll to react with Carbon dioxide (CO2) – and it in turn produces Oxygen (O2) and simple sugars (Glucose or Fructose) – the desired crops translocate to the root system, leaves, stem or fruits (grains) for storage.
This improves the yield potential of the crop.
Thirdly, when one undertakes weed control correctly and timely, it eliminates the possibility of the weeds becoming hosts of disease causing-organisms and pests.
In turn, when pests are reduced, crops grow to maximum potential and the yield quality is not compromised, thus enabling a farmer to sell high-quality produce.
Finally, weed control is essential in the sense that when the weeds are removed manually and left to dry on the field and decompose, they tend to resupply the soil with nutrients, such as Nitrogen, Phosphorus and Potassium.
Weed control is a good agricultural practice that must be carried out by crop producers to help them produce good quality crops with maximum yield potential.
Lastly, weeds can be further suppressed by practising crop rotation, as crops are affected by different ranges of weeds.
Maize may have a certain target range of weeds that may be different from the target range of weeds that attack Tomatoes.
* Hanks Saisai is the Technical Advisor: Crops & Poultry at Agribank.