The season progresses
Jun/13/2012 09:26 AM Filed in: orchard
In the last few weeks, we have had good news/bad news show up in the orchard. On the bad side, we learned that the models we use to control the fungal disease scab were not accurately reflecting reality this year, thanks to bursts of warm weather early on. Apparently scab spore release is not actually caused by degree days, but in a normal year they correlate fairly well with degree-day models. This year, however, there were lots of spores active after the models predicted that all spores should have been released and no longer a concern. This means that our scab susceptible varieties have signs of the disease on their leaves, and will likely have poor fruit quality this year. Once again, we are thankful that our primary pick-your-own varieties are still scab immune, so they look just fine.
As for good news, we were worried about plum curculio damage since we had over a week without the kaolin clay (Surround) on our trees due to rain. However, now that we are beginning to thin the trees, we can see that plum curculio damage is not worse than it has been in previous years. The apples have really sized up, which means we had to begin thinning while we still have clay on the trees. Thinning involves pulling off fruit that is damaged, leaving apples evenly spaced on the tree. There are several benefits to this. First, with fewer fruits, the tree can invest more in each, leading to bigger fruit. Second, any place where two apples touch invariably ends up harboring insect pests, generally ruining both fruits. Finally, we selectively take off damaged fruits, many of which have insect pests inside them. Since we keep these thinned fruits in buckets, the insects can’t get to the soil in order to continue their life cycle. Hopefully this reduces pest pressure over time as we prevent some pests from reproducing in our orchard.