[rimprona] Recent observations on RIMpro

[David A. Rosenberger]

Following are a few observations on RIMpro graphs as I am currently seeing them for Highland, NY:

  1. Based on RIMpro using our NEWA station data, we are now at or nearing full bloom, and we still have not had any infection events with RIM values above 38.

  2. My perception (from my own observations over the past two years, plus what I hear from the Europeans) is that infection periods with RIM values below 300 are not economically important in CLEAN orchards at the BEGINNING and END of the ascospore release period.  More caution is warranted when there are infection periods during the peak ascospore release times between tight cluster and petal fall.  Thus, I hope that no one is continuing to leave trees totally unsprayed into full bloom just because RIMpro has shown no infection periods with RIM values over 300.  (Besides, in many areas, you need sprays by pink bud stage to control mildew even if scab is not a problem.)

   4. Just a reminder about the graph at the bottom of the RIMpro output:  The bright red part of the graph shows mature spores, and that level will fluctuate as spores mature on days with no rain and then are released on days with rain.  The dark red or burgundy layer below that shows spores remaining in the leaf litter.  This declines in a more steady line, but the primary scab season will not be over until all of the deep red color at the base of the graph has disappeared.

   5. I have been comparing outputs from the MeteoBlue and NEWA data for our Highland location.  Because they are using different weather forecast sources, the forecasts are often quite different, which is not unexpected since any and all weather forecasts have a high degree of inaccuracy.  I am more concerned that the MeteoBlue system is indicating extended wetting periods have occurred where that has not been the case based on NEWA data and (to some degree) my own observations. Thus, the MeteoBlue virtualy data is, in my opinion, still unable to accurately ascertain when leaves are wet or dry and will need more fine-tuning before it produces a reliable record of infection events.

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Dave Rosenberger, Plant Pathologist (retired)
Hudson Valley Lab, P.O. Box 727, Highland, NY 12528
    Cell:     845-594-3060
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