'You still want to keep your seed potatoes in the letter'

Sumicidin Super together with oil, has been the reliable basis in Jan-Herman ten Have's spraying schedule against lice for years. "After all, you don't want a reduction. I just think it's an easy and reliable tool."

"It hasn't gotten any easier in recent years," Jan-Herman ten Have begins his story. "Especially after mild winters, the aphids show up sooner. The varieties that emerge early suffer from this." For the arable farmer from Middenmeer, there is also the capriciousness of the soil type. "We have many colorful plots here in the Wieringermeer. As a result, you still have differences in the condition of the crop even within plots."

Zero tolerance
Ten Have grows 50 hectares of seed potatoes every year and purchases S material for a virus-free start. He uses a strict spraying schedule with oil and Sumicidin and a louse killer every other spraying. He has renounced experiments with that approach. "Years ago I did reduce the aphid sprays a bit, but that immediately resulted in a reduction. As much as I might want it to, that just doesn't work in seed potato cultivation. We just have that zero tolerance. And you want your plots keep it to the letter anyway. A setback with a virus is many times more expensive than not spraying once."

In addition to chemistry, intensive selection work is an important pillar of Ten Have's anti-virus strategy. "We drive rounds every week with two selection carts and four people. For the first field inspection I want to have been everywhere at least once. And not for the judge," he grins. "I do that for myself." In line with that principle, Ten Have almost always registers its own seed potatoes for the follow-up inspection.

Just a little stronger
In the past, the seed potato grower has sometimes sprayed with other pyrethroids, but in recent years it has always been Sumicidin Super that he uses in the fight against aphids. "According to my adviser from CAV Agrotheek, Sumicidin is just a bit stronger. They have their own tests, so I value that. And you can Sumicidin Super using it all season, that is also an advantage." Ten Have has already made the decision for the 2023 season. "The Sumicidin is already in the shed," he concludes.