PHYTPROG -I :A WARNING SERVICE FOR COMBATING LATE BLIGHT OF POTATO (PHYTOPHTHORA INFESTANS) IN THE FEDERAL REPUBLIC OF GERMANY.

Although the cultivation of potatoes has drastically decreased in the Federal Republic of Germany in the past years -1976 approximately 415.000 ha, 1986 only about 208.000 ha- an agrometeorological advisory service for an application of pertinent measures against late blight of potato still remains topical.

Advisories are based on the biometeorological model developed by SCHRUDTER and ULLRICH (1965, 1966). It models empirically how the meteorological elements air temperature, atmospheric humidity and precipitation influence the propagation of desease.
It is possible to calculate the minimum period in which an epidemic propagation may be reached.
The procedure does not yield any prognosis of the event "epidemic outbreak of the desease", but only a forecast of the earliest possible date the event may occur.
With this method no statement can be made whether the epidemic will occur or not.
The user of the warning service is relieved of a decision whether to combat late blight of potato or not prior to the calculated day.
By that time a visual checking on the canopy is advisable in any case.

Agrometeorology of the Potato Crop

H. Dommermuth

https://doi.org/10.17660/ActaHortic.1988.214.13