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FieldClimate.com is presenting:

a) the infection progress curve and in dependance of an infection event its incubation progress curves.

An infection progress curve is started to be determined, b) if macrosporangia or sporangia are present and leafs are wet. It increases in dependence of ongoing leaf wetness and temperature. If the infection progress curve reaches 100 the infection can be assumed to be completed. The incubation progress curve which belongs to the specific infection is started with the start of infection. If an infection can not be completed the incubation curve will end too.

c') FieldClimate.com displays the weather conditions with the disease model results. Therefore you can check with one glance for temperature, relative humidity, rain and leaf wetness during the infection.

 

The model is pointing out infection dates for primary and secondary grape vine downy mildew infections. This is the most critical information for this disease. Infections which have not been covered by either preventative or curative fungicides can be disastrous for the yield and or the quality. Information over infection severity is helpful to decide wheather a curative fungicide is needed. 

There are different fungicide strategies used on base of downy mildew models throughout Europe. In situations where disease pressure is mainly low to moderate the following first strategy example is very successful:
*Spray program starts after the first primary infection pointed out by the model with a preventative spray applied at 80% incubation.
*Preventative sprays are applied if weather report forecasts a rain event and incubation period of the last bigger infection event is higher than 80%.
*Curative sprays are applied if an infection period with more than 2mm of rain is missed.
 In high pressure area information is helpful to check the spray program if it could cover most the infections (second strategy example).
*Spray program is started with a curative spray immediately after an primary infection. Note even METALAXYL does only work once in the season if incubation period is not further than 35%. All other curatives should be applied earlier. Take care on resistances does not use products with cross resistance several times.
*In periods with frequent thunderstorms and rains preventative sprays have to be applied. Please take care on new growth, an infection during early summer which takes place 5 days after the last spray has to be answered by curative actions.
*Curative sprays are applied if an infection period with more than 2mm of rain is missed.

The model bases on the publications of MUELLER-THURGAU, ARENS, MUELLER and SLEUMER, BLAESER, HERZOG, GEHMANN and many other workers connected to research network on grape vine downy and powdery mildew epidemiology since the early nineteenth of the last century.