My understanding is that PC is the earliest pest to cause damage.
So now is my problem…
My orchard has stone fruit and pommes in close proximity. 6-7 foot separation between espalier rows is to narrow to avoid hitting the apples/pears in the next row. The stone petal fall and fruit formation will start while some of the pommes are still in bloom.
Will the following solution work?.
Use SURROUND KAOLIN spray on the stone fruit until all petal fall is done before switching to insecticide spray. I am afraid of insecticide overspray no matter how careful I am.
I want some spray on nearly of the fruits and short shoots. You don’t have to have all the fruits covered (esp. for plums which you can’t cover much at all since it beads up). The short shoots you can get mostly covered. That is how the curc navigates from one fruit to the next, they don’t fly that often. You want to make that a very slow road for her. Think of Surround as “friction”, just put up enough friction so the curculio doesn’t do too much damage. I have found plenty of bites this spring, but its on the order of 1-2% so far (it will grow to more for sure). I monitor nightly and if an area is getting hit I may up the coating on it.
In Southern NY I get away with waiting until last apples have lost blossoms before I spray anything. Peaches aren’t usually all that attractive to PC anyway, but PC usually doesn’t become a big factor until those apples have dropped their petals. I’ve never suffered consequences from waiting except MAYBE with E. plums at a few sites. It there’s a decent plum crop I might lose a quarter of the crop when this happens, but I don’t know if PC comes early or late to the plums.
@alan - this is my exact spraying schedule also. The second the last golden delicious blossom falls I begin to spray. This method has worked well for me. I did notice aphids on my new cherry leaves that have grown this week. They have sucked the life from a few leaves. That ends tomorrow at 6am…
Surround spraying is a very different game, you need to have the “friction coat” on during their whole active period as they are not dying. I have heard many people not having good results and I think its because they did not keep on it. Even after almost ten years of using it I still screw up. I was low on time a week or so ago and just hit the apple clusters on some trees, I didn’t spray enough other area of the tree. It didn’t slow the curc down enough and I got lots of damage on a few trees.
One other thing I notice but don’t quite understand is the curc generally visits fruit at a certain size and loses interest as the fruits get bigger. Genetically, her programming is to get the egg down in time to eat the plum seed before it hardens, a hard seed can’t be eaten and won’t drop. Generally this is the case, but I have had late attacks sometimes and I don’t understand whats doing it. Last night I found one apricot tree had serious recent bites on the fruits in spite of the seeds starting to harden on it. Last year I had many late bites on my Euro plums. In fact one reason I was sloppy on my apples was I was getting the plums extra good. Also because I was spending tons of time looking for knots on them. Focus on one thing too much and you lose focus on another. Its one of the big challenges.
Scott, that is so interesting. I’d not considered that PC activity would be longer without poison, even as I send one man out to cover trees with Surround for my organic zealots. Most years I get away with a blanket program of 4 weekly sprays unless the crop is thin. Fortunately, it is not being used at sites with Euro plums. Seems to work for the J’s though.