Benon Kisomose, an agronomist, says now days to practise productive farming without the use of chemicals is really rare.
Farmers use chemicals to protect crops from pests, diseases as well as the weeds especially for those that are operating on a large scale.
He says the use of chemicals offer a cheaper and faster way of killing weeds, but for effective results, a farmer needs to know how to use herbicides properly.
When and how to apply herbicides
Jackson Mabirizi, an Irish potato farmer in Bweyongede village Mubende district says it is important to spray herbicides when the dew on the weeds has dried and even when daytime temperatures have risen.
“My experience with spraying is, it is better to do it after 10am. Spraying weeds while there is still dew on them or immediately after it has rained would dilute the herbicides”, Mabirizi says.
According to Mabirizi ensure that the leaves or foliage are thoroughly sprayed, it is important to follow instructions.
It is important to comply with the given instructions on the label.
He also says it is important to pay attention to the correct dosage and method of application.
After using a knapsack sprayer, wash it thoroughly with soap or a detergent to remove the herbicide residues, which might kill non-targeted plants when it is used another time.
Why you need to know brands
Rebecca Massa, the managing director, Nissi Agro-Vet Company in Mbale says farmers should know that the chemicals used to control weeds are known as herbicides.
“Herbicides are made to kill weeds by directly scorching or by disrupting their biological functions such as respiration and photosynthesis,” she says.
According to Massa if properly used, herbicides tend to be more effective and less time-consuming.
Some farmers remove weeds using tools or uprooting them by hand, this takes a lot of time.
“A farmer to use herbicides is not difficult and can be useful, with this process a farmer does not have to till the soil every time the weeds grow and therefore the soil structure is better preserved,”Massa advises.
Pests and diseases
There are several types of pests and diseases that may cause losses for farmers.
These include insects, nematodes (which are mainly tiny worms), pathogens that include bacteria, viruses, fungi or parasites, vertebrates (usually small animals like rats, mice, birds, flying foxes and bats or bigger animals like the wild boar, pigs, monkeys and baboons) and weeds.
Weeds compete with the main crop for the available resources like water, space, sunlight and plant foods or nutrients.
Weeds can also harbour parasites, insects and pathogenic diseases.
The types
According to Massa the most types on the market are two, selective and non-selective.
“Selective herbicides kill or stunt a targeted type of weed with little or no harm to other weeds, while non-selective herbicides like Glyphosate kill all types of weeds”, she explains.
The latter include those that kill or stunt narrow-leaved weeds or broad-leaved weeds like 2, 4-D and Amine.
With the Simazine and Butanil-S, these are applied at any time before weeds emerge from the soil.
Why you need protection
Massa says herbicide application should be done when a farmer is wearing appropriate clothes or protective gear, because of the effects they have on human health due to their toxicity.
According to Kisomose crops also need protection.
Advantages and disadvantages of using herbicides
Massa says herbicides are relatively cheap, and most of the time cheaper than hiring labour for manual weeding.
But farmers should know that some are being harmful to the soil since they are non-biodegradable.
They are toxic and can cause illnesses and even death. Glyphosate, for instance, can cause eye, skin and respiratory problems.
Herbicides can be used in cases where manual removal of weeds may destroy the crops.
So, the application of herbicides in most cases, is enough whereas the other methods will have to be continually used.
Tips to farmers when buying crop protection products
Make sure you buy products from well-known dealers.
Only buy sealed packages of chemicals that bear their original label and brand.
Always read the label and follow instructions. If you cannot read or understand the label, have someone to help you. Write notes to help you remember.
Make sure that you know what you need and buy the right product to address your problem.
Seek advice from your local agriculture extension worker if you cannot identify what is causing the problem.
Always save the container and receipt from your purchase.
Do not apply chemicals when it is raining or when rain is expected very soon.
Apply in the morning after the dew is gone or evening when it is cooler.
Make sure that the chemical is applied correctly. Incorrectly applied chemicals can kill crops.
Take note of the inscriptions on the containers. These include the brand name, list of pests that the chemical can control net content by weight or volume, name and address of the manufacturer, directions of proper usage.
Storage instructions and the precautions to be observed while disposing off the container.
