DSS adjusted to the wishes of farmers

DSS for the control of Phytophtora has been adjusted for farmers with large acreages of potatoes. Three research farms and six farmers with a large potato area tested the adjustments of the DSS.
On large farms often more then one day is needed to spray all the potato fields. A variable spraying interval is therefore difficulty to plan. But it is possible to adjust the dose of the fungicides used. At one of the research farms the dose is lowered and sprayed in a fixed spraying regime. This has resulted in a saving of two to three full doses. This is comparable with the saving a farmer can accomplish when stretching the interval.
The Umbrella Plan Phytophthora has in an earlier stage financed the lowering of the dose of Shirlan (fluazinam) in varieties with a higher resistance to Phytophthora, which is integrated in the DSS’s, (PLANT-Plus (company: Dacom) and Prophy (company: Agrovision). Recently the Umbrella Plan Phytophtora has also looked at possibilities of lowering the doses of Revus (mandipropamid), InFinito (fluopicolide + propamocarb) and Ranman (cyazofamid).
The Master Plan Phytophtora and the project ‘Growing with future’ (Telen met toekomst) are financing the experiments and the farmers receive intensive supervision from the project ‘Growing with future’.
When lowering the dose often the risk of resistance is mentioned. This can play a role when suboptimal dosages are used, but in this project that is not the case. A dose that is effective under the given circumstances is used. Most producers of agro-chemicals admit that there is some margin in the label doses.
The label doses are specified in tests with a high disease pressure.
PLANT-Plus and Prophy calculate in their decision making process the disease level in a different way. Both DSS integrate the lowering of the doses.

The farmer’s weekly focuses on the way DSS’s works and how they are adjusted to the wishes of farmers with large acreages of potatoes. The Master Plan Phytophtora and the project ‘Growing with future’ (Telen met toekomst), in which WUR is participating, are financing the experiments. The farmers are intensively supervised. In two frames, interviews with a farmer and an employer of Bayer CropScience are presented. The farmer shares his experiences with PLANT-Plus and the employer of Bayer presents his ideas on the use of lower doses.