Knapsack spraying potatoes

Leaf canopies of potatoes develop very quickly.

In a few days, the leaf canopy can become so dense that it forms a barrier which prevents spray drops penetrating into the centre.

This makes it very difficult to control any pests and diseases at the centre of the crop as shown here. If unchecked, this reservoir of pests will cause a rapid re-infection of the whole plant despite a good cover of spray drops on all of the outer leaves.

Higher water volumes are essential for dense leaf canopies like these. A lot of the spray is caught by the outer leaves and less spray, but still an adequate quantity, is caught by the leaves half way to the centre.

But to get drops here into the very centre of the plant, the drops need to be smaller, lighter and more buoyant. To produce smaller drops, you need to use the right nozzle with higher water volumes and higher pressures. This is why, as the crop develops, you are likely to need to increase water volumes. Check your pesticide label for advice.

For more information about using pesticides and which PPE to use, visit www.pesticidewise.com.