I’ve been thinking about what you wrote and you seem to realize that my questions are not specific to you but to everyone trying to grow fruit with the available materials for home growers, but it seems also like there may be some defensiveness, as if I don’t assume you to be an exceptionally competent person, which I do.
However, I’m trying to diagnose what you might be dong wrong and that is a step by step process. For example, I don’t know what you used as a sticker last- you are using the very best control for brown rot but a gallon of tactic isn’t that expensive even if it’s a higher quantity than you will rapidly use up. Although Scot gets good control using a resin based sticker.
It’s hard for me to understand why you are apparently getting worse PC control than even clients of mine that use Surround, it is the same weevil here as it is where you are. And how different in efficacy should the new formula of Sevin be than another pyrethroid like Asana? I don’t really know if professionals get to legally use a higher concentration than home growers and I can’t know if my contractors might be mixing it hot.
I vaguely remember Olpea perhaps suggesting that homeowners and commercial applicators have the same concentration limitations with these pesticides but I don’t look forward to crunching the numbers myself. Maybe this winter.
Other readers have gotten good success in our general region using over-the-counter homeowner materials and it would be nice to know why you aren’t, especially given that you go to the trouble to bag your fruit.
One thing I haven’t asked is how big are the crops on trees getting substantial damage. IME the percentage of damaged fruit goes way up when the crop goes down. It is often difficult to protect light crops.
Weather was cool this spring with many days mostly below 70 degrees. Only few 80s. All sprays used Southern Ag Sticker and 2 tbs vinegar per 2 gal spray with insecticide . Spray was May 7th, May 14th, May 24th. Usually would spray again in June but saw almost zero PC damage. Cool weather and good timing may have helped.
There weren’t still blooms on trees May 7th?. I’m guessing that with the Imidan, you got good protection against PC as the last 2 sprays should have been about right based on what I saw by the beach in Greenwich. Imidan is restricted in NY, though. Last I knew, you could buy it without a license in CT. I don’t see how they could fault a homeowner for not realizing it was illegal in their own state. Probably fine you if somehow you were caught but not to the max. If they caught a landscaper unlicensed to spray with it in their truck, they’d probably fine them about 10 grand.
I only sprayed pluots and plums that had finished flowering. Warm weather started trees flowering earlier than usual then once they were in full bloom weather got cool.
These days I do more than that, I put Indar or Elevate or both in most tanks. Maybe 6 sprays a year. Since I started the combo with those two on a regular basis my brown rot has turned to near-zero.
Right now I am harvesting apricots. I have trees in front which had almost no curc damage and I am getting a large crop. In the backyard I lost 80% due to curc. The odd thing is right next to the cots in front there is a nectarine which the curcs had a love-fest on. Why apricots in back and nectarine in front? I wish I knew. European plums in both places took a fair amount of damage. They are right at the top of the curc favorites list.
My father still bags fruit and gets pretty good results, though it takes him a long time. I’ve moved toward the spray route myself and now lose more to brown rot and animals than PC. This year I got Indar (Tactic as a sticker), so hopefully I can solve the brown rot.
But, being retired lets him bag a lot of fruit and keep a closer eye on things than I do. He noticed something interesting this spring. He saw a lot of PC congregating on mullein (weed with tall yellow flowers). Rather than trying to remove the mullein, he’s been using it as a trap plant. Every 2nd or 3rd day he is going out and knocking them off into soapy water.
Last weekend, he sent me a video of 2 PC mating on the mullein. I don’t think I can post a video here (might be too adult anyways ), but here are a couple screenshots. At least, we assume they are mating- the rolling back and forth could just be some sort of fight to the death…
Sexy… I once went on a Mullein purge on my property having read in a Cornell advisory that stink bugs love the stuff. But then I decided to look first and see if they did on my property. I’ve lots of the stuff growing but have never found either stinkbugs or PC on the plants.
That was obviously the same weather pattern a few miles inland from you where most of the orchards I manage are. My earliest flowering plums and pluots (mostly pluots) did not get pollinated- apparently because of cool weather early in their flowering here. Carpenter bees were all over my cots when they were in bloom but everything disappeared when the Early plum types were in full bloom. I thought they’d be fine because there were plenty of flowers still on them when the pollinators re-appeared, but not so. My attempt to cross pollinate all with a dust brush didn’t do the trick.
Bob Vance good to hear from you. As for the PC I tried a neocontinoid Actara for the first time and while I have some PC strikes they are far less than in previous years. It is expensive, but at .50 ounce per application (5 gallon tank) it will last a long time. Two shots tank mixed with Immunox and a sticker and I may actually get a plum crop. In the past the fruit ripened in June and dropped from the tree.
Better spring for some Indar. Labels are deceiving as far as what they say the ingredients control and myclo doesn’t do much to control later stages of brown rot- Cornell only recommends it for control of blossom blight. You can also try Bonide Infuse which should provide much better efficacy than Immunox.
We use the pyretrhoid Asana here and certainly get excellent plum crops with only two apps at all sites holding a good sized crop to begin with. The orchards I manage are in S. NY and lower CT for the most part and represent about 100 orchards in all.
Maybe most of your PC quickly dies from the sprays and doesn’t get a chance to honeymoon on the flowers I hope to have a similar situation here. I still get some PC bites, but most of the fruit I cut open just have the crescent bite, but the egg died, so the fruit is sound.
I asked my dad how many PCs he’s found so far. He’s been doing it roughly every 2nd day, and is getting 2-3 each time from a single mullein plant (almost 6’ tall). Maybe he’s knocking down the population, but I have no idea how many there are to start with.
My pluots (Flavor Grenade and Geo Pride) both have some fruit on them. I’m not sure if it is a full crop, as I don’t think I know that a full crop looks like on them But, there was enough that I had to thin in spots, but not much.
I agree with Alan about immunox not doing too much for brown rot. But, IMO there isn’t a problem spraying Immunox with the Actara after petalfall, as long as you spray Indar later when the fruit is getting closer to ripe.
I use Immunox exclusively for CAR nothing else. In another couple of weeks I’ll use Captan on my apples for Sooty Sploch and Fly Speck I aslo spray in on my peaches and plums for brown rot, even thought I never had any. As to Alan’s point I never tried a Pyrethren for PC I was using Triazicide but it was ineffective. I just bought a whole jug of Actara so I’m more or less wed to it and so far it works great
The document lists zeta cypermethrin as Mustang Max. So while the active ingredient is the same, I’m not sure if there is any difference (label concentration, etc) between MM and the new Sevin. But, I’m pleasantly surprised that the new Sevin got such a good rating. It also gives 5 stars against OFM, better than Avaunt, Assail, and Actara (4, 4, and 2 stars).
I’m not sure why they have such a wide range for gamma cyhalothrin (active ingredient in Triazicide, though they list it as Proaxis) . Maybe there are certain conditions where it works. But, I remember having issues with it in the past, as have many on this site.
Imidian is the only thing in the list with 5 stars.
The mode of action is the same for Assail and Actara (4A), but Actara gets a much better rating for PC. Actara does get a lower score for OFM (4 vs 2) and borers (3 vs 0).
From the link Moocks posted earlier in this thread:
If plum curculio infestation occurs and a rescue treatment is needed, organophosphates and neonicotinoids can provide curative action up to two weeks after plum curculio
Two weeks is a lot of kickback. A big benefit to Actara and Assail.
Avaunt also works primarily by lethal activity, but ingestion is the important means for delivering the poison.
The rotation of these two modes of action is critical to successful plum curculio control. Avuant needs to be used prior to any neonicotinoids because Avaunt must be ingested to work effectively, and the neonicotinoids have that anti-feedant characteristic. If needed use Avaunt first followed by neonicotinoid insecticide.
This seems to be saying to use Avaunt in the first spray (maybe on apricots and pluots), then for later sprays include a neonic, such as Actara or Assail.
Unfortunately, those are almost certainly Rhinusa tetra, the Mullein Weevil, rather than C. nenuphar, the Plum Curculio. R. tetra is curculio/weevil specifically adapted to reproducing in mullein, the way C. nenuphar is adapted to pome and stone fruits. There are hundreds of species of weevils in North America, each generally adapted to a specific small group of plants for their reproductive activity. Many of them look alike to the naked eye. But those little buggers on the mullein pose no threat to your father’s apples.
Wow! Are you an entomologist and knew that off the top of your head or did you come across it on google? Either way, I’m impressed, though I am disappointed that my dad has been pointlessly reducing the population of Rhinusa tetra…now it is the lesser of two weevils…
I asked him if he tried hitting the trees and seeing if he could collect any falling PC in a sheet. But he said he sees no weevil, and hears no weevil…
However, my research is on the ground over several years and Asana has worked very reliably all by itself at all sites for PC.
Assail is the only non OP said to have kickback, so I often use that with Avaunt, although one university rec I read recently advises against it because Assail kills them before they get a chance to be killed by Avaunt. That seems to me like a good defense against developing resistance. The Assail also works against pear psyla and when sprayed at the base of trees very well against peach borers, probably partially because it is locally systemic, which also probably explains the kickback and ability to kill eggs or larva already in fruit.
One year I used only Assail in my nursery just as an experiment and the results were acceptable.
Not stop, but control yes. I see a lot of discussion about Assail, Asana, and even Imidan. The key is you have to hit the Trees with Imidan right after petal fall. The first time PCs became an issue for me I asked Dr. Chris Berg at the Alison Smith Center in Winchester, VA what to do. (He is really good BTW.). He did not even blink as he said Imidan - as per the label and the Spray Bulletin. I know my chemical supplier - Helena, has recommended Assail because there is less danger it will kill the pollinators - a concern for all of us. However, it is not effective IMHO. But, if you time it right nothing beats Imidan and you have to use it twice. It comes in water soluble bags, which is a pain, but if you do not have enough trees and you use a respirator you can put the bag in a gallon if distilled H2O (stir it up good with a face mask) and pour off 1/2 into 50 gallons of water if you need that much or less by proportion. Alternatively, if you have a good scale, you can step it down by weight, but for crying out loud, use a respirator, this stuff is nasty. Usually my petal fall hit includes AgriMek (RUP to get the mites), Imidan, Manzate ProStik, Rally, Inspire S, Calcium, Boron, Harbour (Fireblight), an anti-foaming agent, a non-ionic surfactant (for the AgriMek). If I use Imidan twice, it really cuts down on the PC, much like using Cuprofix early on helps the Harbour later, which I use 3 times or so. BTW, Dr. Yoder, (VPI - Alison Smith Center) before he retired, used to say to me not to worry about a little Streptomycin damage on the leaves (the yellow corona on some cultivars). It beats Fireblight he would say. Keep in mind you can track when things will be needed visibly with petal fall, but the Cornell Maryblyt NEWA page (search on Google) will tell you when Fireblight and other risks are happening by your geographic location.
), but here are a couple screenshots. At least, we assume they are mating- the rolling back and forth could just be some sort of fight to the death…
But, there was enough that I had to thin in spots, but not much.