Evaluating your fungicide schedule (continued from last month)
Evaluating your fungicide schedule
The fungicide cover by your previous treatment is gradually reduced by plant growth and rain.
RIMpro helps you to estimate if the cover is still enough or should be renewed just before the next rain event.
The properties of all fungicides registered in Australia have been entered in the system and will be updated when new information becomes available.
When you enter the treatments on your orchard blocks, the system estimates the decrease of the fungicide cover based on a growth model, and the wash-off by rain. This can’t be more than the best estimation of the situation as the system does not know the quality of your spray application.
Figure 2 shows the fungicide cover for the infection event in the example explained before. A protective treatment with Delan had been made on October 5, just before the infection event on October 6.
You see the cover during the germination window of this pervious infection was 70–40% which is enough (% fungicide cover on left axis). But the wash-off by the rain causing the infection decreased the fungicide cover to only 30–20% during the infection October 9. For a high inoculum orchard this is definitely not enough and curative treatment would be necessary.
During the infection 13–14 October the remaining fungicide cover is less than 10%. Foreseeing this infection event a protective treatment on October 12 would have been necessary.
The essence of integrated weather forecast
Scab warning systems have existed for almost a century. But until they integrate local weather forecast, they are telling us yesterday’s news.
RIMpro runs in real time and extends simulations using 7 day weather forecasts—so you can see potential infection events coming, and can plan appropriate actions.
As curative fungicides are expensive and less reliable because of resistance, it is essential to build your scab management strategy on intelligent use of contact fungicides and use systemic fungicides only as last resource.
For more information and contact details, see Tree Fruit September 2015
