RIMpro Scab forecasting model

RIMpro was released 14 years ago as the first scab forecasting model of a new generation. RIMpro-scab predicts the maturation process of overwintering scab lesions as the basis of its forecast. RIMpro is now used for the management of apple scab in XXXXX Mature ascospores are released during periods of rain if light and temperature regimes are met. Severe infections occur if a high inoculum load is discharged and the conditions are suitable for infection. Less severe infections will result if spore discharge is reduced or if infection conditions are suboptimal. RIMpro-scab simulates these processes on the basis of weather data, providing a clear graphical display. Crucial scab infection events are readily recognised in fruitweb.

Scab management for individual farms

Good scab management crucially depends on the presence of a sufficient fungicide cover during periods of spore germination, heaviest inoculum loads requiring the most thorough cover. RIMpro users are able to recognise mature spores in their model, and use this information as a base for decision-making for imminent periods of rainfall. Since fruitweb continuously monitors the course of an epidemic, it is possible to apply fungicides within the infection period, thereby preventing or weakening disease progress. If fruitweb indicates that an infection has already taken place, systemic fungicides with a curative mode of action can be applied in order to retard further growth in planta.

The fruitweb.info platform further simplifies the interactive use of RIMpro. A special adaptation of RIMpro downloads current weather data from the internet, thereby reducing your telephone bill and avoiding complications arising from the use of a dedicated software to download data. This software is, however, available from our online shop. It may also be used for simulating the degradation of fungicide covers.

1 Leaf wetness periods
In the lower part of the graphical display, you will find light blue bars directly above the time axis. These indicate leaf wetness periods as calculated by RIMpro on the basis of weather data.

2 Periods of rainfall
Immediately above the light blue bars there are dark blue bars documenting the recorded periods of rain. In the example shown here, rain started at 8 p.m. on 1 May.

3 Ascospore potential
The amount of as yet unripe ascospores is indicated by the brown area. 100% of ascospores are unripe at the beginning of the season. As spores ripen and become discharged in the course of spring, the amount of unripe spores decreases. In addition, unripe spores on fallen leaves may be lost by substrate decomposition.

4 Ripe ascospores
Ripe ascospores are indicated by the red colour directly above the brown area. Ripe ascospores are ready for discharge during the next rain. A large amount of ripe spores indicates that a serious disease outbreak is likely to occur during the next rainy period.

5 Discharged ascospores
Discharged ascospores are indicated by yellow bars. Ascospores alighting on apple leaves will begin to germinate. During germination, spores are highly sensitive to contact fungicides. Fungicide treatments during this period are therefore very effective.

6 Infecting spores = RIM Wert
A red line indicates an increasing number of spores at advanced stages of germination, ready to penetrate the leaf surface. These spores do not require free water (leaf wetness) for subsequent stages of their life-cycle. Further, they are no longer sensitive to contact fungicides. Curative fungicides are required in order to fight scab infections at this late stage.