After the loss of diquat is quick down the only effective contact agent against small weeds before emergence in potatoes. Crop advisor Jacob Swart of Agrifirm and arable farmer Geert Andringa (photo) from Minnertsga call the effect perfect. "Last year we treated our entire seed potato area with it," says the grower.
In the cultivation of high-quality seed potatoes, neat work and precise weed control go hand in hand. Geert Andringa is no different. The arable farmer from Minnertsga grows 70 hectares of seed potatoes of various varieties for trading house HZPC. He tackles weeds firmly at the start of cultivation with Quickdown. "Weeds not only compete with my seedpods for water and nutrients, they also contain host plants for pests and diseases, such as virus-transmitting aphids."
One pass gives weeds free rein
The Frisian grower has been combining planting and final ridging in one pass for several years now. This saves time and money, and poses less risk in terms of weather. Weeds that germinate after that have in principle free rein, because there is no more earthing. Andringa: "That does not have to be a disadvantage, as long as you can use a contact herbicide in time. With diquat you always got the weeds under quickly, but that is no longer allowed. 2 years ago, in consultation with Jacob Swart, I had a few plots of quick down sprayed. That worked perfectly. Last year, the step to apply it to the entire 70 hectares was not a big one anymore."
Substantial savings after emergence
The seed potato grower puts 0,4 liters of Quickdown before emergence, preferably on moist ridges. Adding a little mineral oil improves the contact effect of the herbicide. It is not an expensive spraying, Andringa has now experienced. "In fact, thanks to the effective pre-emergence weed control with Quickdown, we save something on soil herbicides. That can easily save tens of euros per hectare. In addition, the options for post-emergence weed control in seed potatoes are very limited."
A lot of demand
Agrifirm's crop advisor Jacob Swart points out that the method followed by Andringa - building the legs and definitive back in one working pass - is being widely adopted. "Many seed potato growers do it just like Geert and that partly explains why there is now more demand for this application of quick down", he explains. "It takes a little longer for the plants to get to the top, but the advantage is that you can time the weed control better. In that longer period until emergence, more weed seeds germinate and you can tackle that small stuff perfectly with a contact herbicide."
Timing
The best spraying moment for maximum results is when the weeds are just above. When the ridges are moist, a soil herbicide can be added for longer duration if desired. This is worth considering, especially with high weed pressure. The addition of a weed oil enhances the contact effect of the soil herbicides and the effect of Quickdown, as indicated earlier.
Everything except grasses
Until last year, Agrifirm advised both diquat and Quickdown for this. Diquat has since disappeared from the scene. "Quickdown works best on small stuff. It tackles all weeds, except grasses," says Swart. "The most common weeds in northern seed potato cultivation are melded, pig grass, chamomile, swallow's tongue, wall and black nightshade. The product has no problem with that at all." Andringa can now confirm this. He is therefore determined to use the drug again this year.