Spraying Crops Against Pests. [Photo, Standard]

In a bid to cut costs and make more from less, some farmers have devised shortcuts when doing important farm aspects like crop spraying. But experts are now warning that shortcuts are costly and have disastrous consequences.

Fergus Robley, the General Manager, FMD East Africa, the Massey Ferguson distributor points out that it is critical to adhere to best practice while using responsible and effective amounts of agrochemicals.

“It is important to remember that both too much chemical and too little have negative consequences. Excessive use of chemicals can burn the crops which diminish the yields and too little will allow the survival of the targeted challenge, such as pests, which will continue to cause further problems and again will limit yield,” he points out.

Ahead of the planting season when farmers across the country are busy preparing their farms as they wait for the long rains, Robley gave a few insights on responsible use of agrochemicals and maintenance of spraying machinery. After planting, the next step is protection of the crop by careful spraying with agrochemicals.

Preparation is key

Robley says like using any machinery, preparation is key to achieving your objective of the effective coverage to combat weeds, grass, insects, pests and diseases. He notes that agrochemicals are the biggest cost for farmers after fuel. Accordingly, thorough checks and maintenance of sprayers should be carried out in advance.

“This will help to give good results without breakdowns and down time. Robley says attention should be paid to the booms, water tank, pump, pipes, filters, regulators, agitator, nozzle holders and nozzles.

“The oil in the pump should be changed every season and then the level should be checked daily during the season. It is important that the oil used is the one recommended by the manufacturer. Hoses which are perishing and have cracks should also be replaced,” says Robley.

The stability of the pump pressure delivery, and pressure regulator settings and nozzles should be checked to identify any issues, such as damaged or worn valves. This is done using a visual inspection of the spray pattern and then measuring the delivery, in water volume per minute, as per the nozzle specifications using a calibration jug.

He says agrochemicals suppliers give recommendations for the water rate and droplet size which means you must have the appropriate nozzle type and correct nozzle to achieve the planned spraying. The filtration and regulator control valves must be in good working condition.

The main filters should be cleaned at the end of every season and again before the next spraying season. Thereafter they should be cleaned every day of spraying, or more often if the water is dirty. The task of daily filter cleaning while spraying is one of the key contributors to getting the maximum benefit for yield protection. This helps prevent delays and gives consistent pressure during the small windows of opportunity for spraying.

Correct nozzles

All nozzles supplied by the premium brands are colour-coded to a common international standard, but as a minimum requirement, a flat fan nozzle should be used for herbicides and a hollow cone for pesticides and insecticides. When using flat fan nozzles, the fan pattern is slightly offset by a few degrees to avoid larger droplets being formed where the fan patterns meet which can burn the crops and cause unwanted yield limitation. After ensuring the sprayer is in good working condition, calibration must be carried out for each application. Calibration is the process of checking a measuring instrument to see if it is accurate.

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Crop spraying