Using chemical poisons in crop production

Chemical remedies such as herbicides, fungicides and pesticides are increasingly being used in most crop production operations as they play a vital role in ensuring a successful season.

Hanks Saisai, Agribank’s technical advisor for crops and poultry, explained that herbicides are chemical remedies that are traditionally sprayed on weeds to reduce their competition with desired crops.

According to him, fungicides are conventionally used to control fungal diseases in crops such as tomatoes and potatoes. Pesticides, on the other hand, are used to control organisms such as ants, insects and worms.

“There are, however, several considerations that farmers must bear in mind before applying these remedies,” he said.

The first consideration is understanding the problem that needs to be addressed.

“For example, a farmer must not buy a herbicide such as Glyphosate to address an armyworm pest outbreak. Moreover, it is crucial for the farmer to know the active ingredients in the chemical remedy and the target group of pests, fungi and weeds it eradicates,” Saisai said.

Additionally, the farmer is advised to check whether the remedy is selective or non-selective.

“This will ensure that they understand that selective remedies only target certain problematic micro-organisms and spare beneficial organisms such as ladybird bugs and praying mantises that are natural enemies of pests such as aphids and ants or insects as they prey on them,” he said.

Handle with care

According to Saisai, the second consideration is checking the expiry date of the specific remedy to ensure its effectiveness in addressing the identified problem.

He added that the farmer must follow the application instructions, adhering to the correct dosage and mixing requirements to give the chemical remedy a chance to correctly carry out its function.

Thirdly, he said, it is important to check whether the chemical remedy is corrosive or non-corrosive, as this will assist the farmer to avoid injuries such as skin burn when handling the remedies.

“Most remedies must be handled with protective gear that prevents corrosive injuries that may result from the remedy’s reaction with the skin.”

Finally, the last consideration when buying and using chemical remedies is to have an application programme that rotates the products to address challenges such as weeds, fungal infections or pests.

This rotation ensures that the targeted weeds, fungi and pests do not develop resistance against the remedy used,” Saisai explained.

“Crop farmers should understand the mentioned considerations to successfully correct issues that may limit yield potential,” he said, critically adding that after using the chemical remedies, there should be a withdrawal period before one can harvest and consume produce.

“Usually, the withdrawal period is always indicated on the instructions for use leaflet. If one consumes produce that was sprayed using chemical remedies, it may result in death,” he warned.