Since switching to a different rhizoctonia fungicide, Korjan and Gerben Huizinga have seen cleaner seed potatoes rolling through the reading room. "The skin quality is visibly better. And we have less reading work due to rhizoctonia. We simply do more in a day."
"We have soil here that is 18% to 23% silting-off. So not the greatest risks. "But doing nothing is not an option," says Korjan Huizinga. All 40 hectares of seed potatoes that he and his cousin Gerben grow annually are treated with peat. all star applied. "Sometimes we also do a tuber treatment in the most sensitive varieties; that depends on the plot and the lot," Huizinga continues. The seed potato growers know their plots inside and out because all their seed potatoes are grown on their own land around their farm in Garsthuizen, Groningen.
2023 will go down as a disappointing season for seed potato growers, says Huizinga. "We started late, wet and cold and we had poor fruit setting. With this year's yields and the ever-increasing cultivation costs, profitable seed potato cultivation is not becoming any easier." Still, he doesn't want to come across as negative. "Dutch seed potato cultivation certainly has a future. But we do have some hurdles to overcome. Tackling aphids is becoming increasingly difficult. Just look at the high reduction percentages. It sometimes seems as if the aphids occur earlier every year."
Focus on quality
Despite all the challenges and the pressure on profitability, Huizinga wants to continue to focus primarily on quality in its approach to seed potato cultivation. "Of course the kilos are also important. But growing a nice, clean and healthy product is the top priority." For this reason, Huizinga gives the seed potato tubers maximum protection when planting. Three years ago he switched to a soil treatment with the (then new) fungicide Allstar. "That was a tip from my advisor at WPA-Robertus. And because we are a test location for BASF's grain fungicides, we had also heard about Allstar's technical results through those contacts," Huizinga explains his choice. He applies the fungicide using the three-cap method with one cap directed forward and two caps towards the ridging disks.
Noticeably cleaner
Huizinga now appears to be a satisfied user of the rhizoctonia fungicide. “It certainly lived up to our expectations,” he guarantees. "The seed potatoes are noticeably cleaner than before. The rhizoctonia causes us little work in the reading room." Huizinga is also positive about the practical side of Allstar. "With 0,8 I/ha you don't need a lot of it and the mixability is also excellent. But we never put so many things in the tank at the same time, so that honestly wasn't a problem in the past."
Huizinga has to think about the question of whether Allstar has improved the yield of their seed potato cultivation. "We have the impression that we have more kilos in size, but we have not determined this objectively. Every year is different and we do not do any tests ourselves. But we certainly benefit from less work during sorting. You just do more in a day. And that also makes a difference in job satisfaction." But the biggest advantage for Huizinga remains the positive effect on peel quality. "And I am convinced that with a nice party you will also do better financially," he concludes.
Great tastings with Allstar for 10 years
"Our search for a good rhizoctonia product started about fifteen years ago," says BASF researcher Rolf Scholtens. "We tested various active substances and formulations and at one point Allstar was rolled out. And we have been testing it for about ten years now." BASF's own tests are on rhizoctonia-sensitive land in the Noordoostpolder. "In the early days we did the trials in ten varieties, but that has now been reduced to four: Agria, Spunta, Innovator and Fontane," says Scholtens. Allstar is also regularly put to the test at the Kollumerwaard experimental farm and at the Vertify research institution. Many seed potato growers have seen these tests and have switched. Scholtens advises many growers who are in doubt to simply try Allstar on one plot and experience it.
More return
The common thread in all research results is the higher number of stems and the even emergence, the researcher knows. "In cold years we often see faster emergence. The softness of Allstar really gives an advantage." Bottom line, BASF sees in all tests that the fungicide produces more tubers and kilos in size. “It varies per year and per location, but on rhizoctonia-sensitive soil the difference in return can be as much as €1000 per hectare,” says Scholtens.