Recorded Pest Message – May 22, 2007
This has turned out to be a more difficult apple scab season than I thought. The good news is we are nearly at the end of primary scab season. Orchard Radar predicts that 99% of overwintering apple scab spores will be matured by Saturday, May 26 in the Greenville area, and by Monday, May 28th in Newport County. That means in the Greenville area, the next wetting period after Saturday will probably release the last of the overwintering spores. In Newport County, we can expect the end of primary scab season to be after the next wetting period after Memorial Day.
The bad news is I have found apple scab lesions at several orchards over the past week. In orchards with apple scab lesions now, it is very important to keep the leaves and new fruit well protected with fungicide. The prolonged, wet period over this past weekend was very bad for controlling apple scab. I am afraid the scab situation will get much worse before it gets better. If you are finding scab in your orchard now, probably the best option is to spray Sovran or Flint in combination with a protectant fungicide such as Captec. Apply both chemicals at full rates. Syllit or Dodine can also kill spores in the lesions. What we really need is several weeks of dry weather to kill existing apple scab lesions. Remember, it takes about 2 weeks after as apple scab infection period for the lesions to start appearing.
Plum curculio, I saw one pc egglaying scar today. This was probably made during the hot, humid weather of last week. I expect pc will become very active when the temperatures reach 80 degrees later this week. PC become particularly active on warm, humid evenings. If you have not applied an insecticide since Friday’s rains, plan to apply an insecticide very soon. Use Imidan, Avaunt, Calypso or Actara.
I’ve seen mites at a few more orchards than last week. Now is a good time to apply a miticide if your trees were not sufficiently sprayed prebloom. Use Agri-Mek, Apollo, Savey or Zeal. Agri-Mek will also control apple blotch leafminer. Speaking of ablm, I have not seen any lm adults or eggs this season. I haven’t looked very hard for leafminer, but I am surprised I haven’t seen any.
Thanks for calling – next message will be recorded Tuesday, May 29th.