Hans Schalk sets the bar high for his seed potato cultivation

"Virus-free and with perfect skin quality" is how arable farmer Hans Schalk describes his ideal seed potatoes. He tries to turn the challenges this entails into opportunities as much as possible. He pursues his cultivation goals through variety selection, optimal tuber protection, and sound soil management. "The whole package has to be right."

In Schalk's seed potato cultivation, craftsmanship is paramount. The Groningen-based arable farmer also enjoys using modern technologies to achieve his goals, including the Optima Q optical sorter. He also relies on image recognition and AI applications. A fellow farmer uses a spot sprayer for seed onions, and Schalk is seriously considering a selection robot. "I have high expectations for that."

PB1 cultivation under mesh
On his 65-hectare seed potato acreage, Schalk grows pre-basic material from mini-tubers. "I generally aim to deliver S's, but maintaining a zero yield is becoming more challenging every season due to virus problems. The range of crop protection products is becoming increasingly limited, and the risk of resistance is increasing," explains the seed potato grower. He tries to manage the virus problems using various tools.

On the one hand, Schalk focuses on resilience. In his variety portfolio—which includes more than ten varieties from various trading houses—older varieties are increasingly making way for modern varieties with better resistance. On the other hand, he's looking for cultivation measures to prevent infection. Together with fellow seed potato growers, he's experimenting with PB1 cultivation under mesh. "It's a proven technique for keeping aphids at bay. You create an extra generation without the virus."

'The peel quality is central'
The appearance of his seed potatoes is just as important to Schalk. "The skin quality is key," he says. "Some of my seed potatoes go to destinations around the Mediterranean, where they are critical of external defects. I don't have soil susceptible to Rhizoctonia, but I want to be sure that my starting material goes into the ground clean and comes out clean. That's why I pre-treat with all star."

Don't take risks with rhizoctonia
"The risks of yield loss and quality are too great for most seed potato growers to ignore rhizoctonia control," says Pim van de Griend of BASF. He is responsible for the rhizoctonia trials and knows the disease inside and out. "You simply want a stable product with robust performance. You can't correct it during cultivation. Fortunately, most seed potato growers know from experience which fields require a rhizoctonia treatment. In practice, you usually see them take no risks and apply a pre-treatment at planting."

Stable in rhizoctonia trials for eight years
"We are conducting the most rigorous tests on the product in our own trials," explains Van de Griend. "These trials are in the Noordoostpolder on plots of very light soil with a heavy Rhizoctonia infestation. If a product works well there, it will work everywhere. We see all star For eight years running, Allstar has been the best performer. This is usually also the case when Allstar is included in third-party trials. Allstar has performed very consistently over the years. Compared to both untreated and other rhizoctonia products, Allstar plants consistently yield more—up to 8%—and therefore more kilograms in the available sizes. It's really quite simple: treatment with Allstar is always beneficial.

Tests provided the proof
Schalk's advisor, Cor Eldering of Van Iperen, remembers the introduction period of the rhizoctonia fungicide. "We knew the good properties of all star BASF has been trialing it for some time now. It's an excellent product for preventing rhizoctonia and also helps control black spot and silver scurf. Schalk was one of the first growers to receive a trial package. Later, we switched over en masse with our seed potato customers.

The seed potato grower confirms the positive experiences with all star"I think it's a fantastic product. It's very user-friendly. You only need a small amount, and it mixes well with the fertilizer in the tank. It saves me a lot of work at the sorting table, but the optical sorter is the one benefiting most from it now," he says with a grin.