In favorable weather it is perfectly possible to spray seed potatoes with Spotlight Plus and Quickdown, according to tests in 2019 and 2020. Under warm, dry conditions it is better not to spray with a low spray volume and fine droplets. In a summer with less favorable conditions, a fourth spraying with Affinity Plus would be necessary.
This year, seed potato growers have succeeded in killing the leaves without Reglone or Finale. The conditions for the operation of Spotlight Plus and Quickdown were good thanks to the combination of sunny conditions and sufficiently high humidity in July. But the narrow range of resources made it more exciting. With Reglone, the crop could always be properly and quickly sprayed open to make the stems accessible for subsequent spraying. Advantages of this were also good planning for sorting and a faster stop on virus and bacterial diseases.
Waterlogging and bacteria
Alternative methods are haulm topping and leaf pulling. These methods have the disadvantage of intensive driving through the crop, possibly resulting in structural damage. There is then a chance of flooding, and thus the spread of bacteria.
The problems were reason enough for the Arable Farming Branch Organization to commission Delphy in 2019 to conduct research into the best method of haulm killing. Extensive tests were carried out in 2019 and 2020 to compare various spraying schedules, spraying techniques, new agents and mechanical methods.
Read the full article about this research into haulm killing in seed potatoes in the December trade magazine Akkerwijzer