New App available for the control of Phytophthora in potato

Wageningen University & Research and Agrifirm have cooperated in the development of a new Phytophthora advisory App which has recently been made available to growers on the Akkerweb platform. WUR supplied the new computation module and Agrifirm the interface for the new App. The development of the App was in part funded by PPS PL2.0 (Precision Farming 2.0).


Following tests of the new App at more than 80 growers in 2016, the warning system was officially launched this year. Growers can use the new App to compute the risk of Phytophthora infection of foliage and tubers on the basis of the weather forecast. The App gives preventive advice when the critical threshold level will shortly be exceeded and the protection of the crop is no longer adequate. The App also gives advice for a curative or stop spray treatment when the critical threshold level has already been exceeded. The App will be made available under the Agrifirm label.

The aggressiveness of the various Phytophthora (potato late blight) genotypes and the influence of the weather conditions are both very different from 20 years ago. The new Phytophthora App determines the risk of infection on the basis of the influence of the weather conditions on the formation of spores, their dispersion and the resultant infection.

The EuroBlight network, of which Wageningen University & Research is one of the coordinators, tracks the genetic changes in Phytophthora infestans, the cause of potato blight. The results from these projects are incorporated in the various warning systems.

These systems determine the protection of the crop on the basis of the specific properties of the various fungicides. The new App incorporates the current data for the effective period, curative effect and protection of new growth from the Euroblight table. This data is based on field studies carried out by participants in the EuroBlight network in various countries and years.


Oospores formed by the fusion of A1 and A2 types can survive in the soil for years. In specific weather conditions these oospores can then serve as a primary inoculum source and infest the crop. A special function in the new App estimates this risk and gives an effective response. This is a unique function that is not offered by any other decision-making support App for Phytophthora.

Specific weather conditions are also required for tuber infestation. The Phytophthora App warns of these conditions so that the grower can make timely use of specific fungicides that offer appropriate tuber protection.

The App is available under the Agrifirm logo in the Netherlands and under the WUR logo outside the Netherlands. The App is currently being tested in different countries including China.