The techniques employed generally produced positive to very positive results. For the spring harvested crop the Botrytis incidence on the foliage was reduced by 60-80% and the Botrytis damage on the harvested fruit was reduced 45-70% from the unsprayed control plot. In addition, the organic treatments were comparable to slightly (<10%) poorer compared to the chemical fungicide treatments on the remaining acreage.
Perhaps due to environmental factors, the incidence of powdery mildew was very low to non existent in all plots, so no valid comparison can be made in regards to the methods used for powdery Mildew management in our research plot, Additionally, probably due t o the extreme amount of rain and nearly continual cloudy, low light days in March thru April, a normally minor pathogen, rust (Puccinella sp.) had a tremendous outbreak in all plots.
The farmer commented that this was by far the worst damage from rust he had seen in more than 15 years of growing raspberries. The rust damage generally caused plant decline, reduced photosynthesis, lower Brix readings in the leaves and harvested fruit and in heavily infested areas, actually caused plant death. In addition rust spores damaged much of the fruit making it cosmetically inferior and/or unmarketable in the fresh raspberry market. This pathogen deserves more study and we wish to include it in our 1995-1996 work..
