Crop spraying

The knapsack sprayer is ideal for controlling small outbreaks of pests, as it’s economical, can be applied quickly, and is very accurate, says Bill Kerr.

- Bill Kerr

With spraying technology becoming ever more sophisticated, the humble knapsack sprayer tends to be used less and less frequently. Yet this device is ideal for many applications.

For example, many tomato farmers who encounter a patch of red spider mites on their land haul out their large mechanised rigs and spray the entire land. Yet it’s often far easier and cheaper to use the simple knapsack sprayer to spray the patches with a little overlap.

As a tomato grower, you might reason that a patch of spider mite in one location means that the pest will be present elsewhere on the land and this justifies spraying the entire land. You should bear in mind, though, that most agricultural pests in South Africa have natural enemies, and by spraying the whole land you can end up eliminating the insects that can control the pest.