So…I’ve had all winter long to order my supplies but of course I wait until the last minute to check my inventory and I realize- contrary to what I THOUGHT I remembered- that I am almost out of Kocide 3000 copper. And of course the local suppliers don’t keep it on hand and it will be 7 to 10 days before my order gets here. Buds are swelling and I really need to get my copper and oil on this weekend.
I know there are lots of threads talking about different copper formulations and types, but I don’t remember seeing anything on copper sulfate. I’m certain this is a very dumb question for most growers, but I’ve never used anything but Kocide for last 11 years and I’m very uneducated on copper, so I’ll go ahead and admit my ignorance and ask if there is any way I can use Copper Sulfate? Is that a totally different product? THe co-op has it in stock so its available immediately, but it sounds like its mostly used to control algae in ponds? Any way to use this as my copper treatment for my copper/oil spray? Thanks
I’m not about using it for Peach Leaf Curl and other fungal maintenance.From reading,it sounds like,the stuff that’s used to kill tree roots in sewer lines.
I remember reading about Bordeaux Mixture using copper and lime but didn’t realize the copper sulfate was the copper involved. Then again, for all I know copper sulfate could be very similar (or very different) to what the Kocide 3000 is. The label on it says Copper Hydroxide. I have no clue what the differences is, but I’m sure some people here will! THanks Brady. Lets see what others say…Im still nervous about it without more experienced info, you know, but that article sounds good
Honestly, now you are opening a whole new area of discussion that I’d love to explore with others here. And that is the question of why I am so married to the idea of copper and oil for a late winter treatment. I’ve always done it and lots of people recommend it, but I really don’t know if it is worthwhile compared to other things. Specifically, I use both Captan AND miclobutanil during the growing season. Both are fungicides. So do I really need a different one for dormant/early bud swell spray? Could I just use the Captan or Miclobutanil as my first dormant spray? I feel like Copper does better on my peach leaf curl and that is based on some minor experience but not a thorough testing or scientific method, so I certainly could be wrong.
So what say everyone. Is copper/oil really much better than if I used Captan or Miclo right before bud break?
It probably does matter,as what the target is.I’m trying Captan,for the first time,against Brown Rot Blossom Blight on my bush Cherries and spraying some other Prunus just in case.But I haven’t read of it being use specifically for PLC.
Myclobutanil (Immunox) was a new one,used last year and it helped a lot,reducing BRBB,but a decision was made to switch,because of being a systemic and I’ve read that a resistance can be built up,unlike Captan.
I think so. Different fungicides control different types of fugi. It happens that copper is better at control the fugi that causes the PLC.
About using blue stone alone in spray. My understanding is that you can as long as you use the correct amount. I mixed Bordeaux myself every year. As far as I know , adding lime to the copper solution is to make the solution milder to the tree also stick better. But if a mature and dormant tree should be able to handle the copper alone. Well, this just my understanding from what I read, I have never spray blue stone solution alone. I always mixed with lime according the formula
My two biggest offenders are plc and fire blight. I spray only twice a year, at leaf drop and before bloom, with copper and dormant oil. I haven’t had a problem since I started spraying. I sometimes skip the spray at leaf drop if blight wasn’t a problem that year. I’m happy that I get away with very minimal spraying.
I have heard that chlorothalonil can be used against PLC. This spring will be the first time I will try using lime sulfur for PLC. If it is effective, I will switch from copper to it.
Thanks Tippy. I’m curious why you are trying to get away from copper? Is it fear of the buildup in the soil under the tree? I ask because its always been really effective for me so I wonder why you’d switch?
You should be happy you can get by with just 2 sprays. I’m certainly jealous of your southern CA climate! Here in the southeast, I have to contend with PLC, fire blight (in extreme- occasionally to the death of apple and pear trees), brown rot, Black rot (on grapes), powdery mildew, blossom rot, pear rust, cedar apple rust, and more!!! And far worse than all of that is the unbelievable insect pressure- especially OFM and PC and peach borers among others. I have to spray for one or more of these diseases and pests about every 10 days or I can loose my entire crop (especially with stone fruit) in just a day or two. So I do hope you know how different things are for us growers on the other end of the country and how lucky you really are. I’d like to be organic but it just isn’t practical here.
Quick question - for these dormant fungicide sprays - do you guys spray any time of day with any amount of sunlight or do you do it only in early morning or evening in non-direct sun like you would if the trees were leafed-out?
I wasn’t trying to rub it in or make it sound like you can get away with doing less. Sorry if that came out badly. My intention to the OP was targeting specific major offenders and whether your copper product can deal with them. I don’t get PC in my area, but I do use pheromones traps for the OFM. I also wonder if my neighbors’ fields of sunflowers provide some biological control for OFM.
I occasionally have to spot spray with spinosad, myclobutanil, and chlorothalonil during the active growing season. I don’t consider myself an organic gardener at all. I just do the minimum for my area if I can get away with it.
I usually do evenings when I don’t expect rain in the next several days. No idea if it’s better or worse, but I pick evenings because it’ll have longer time drying before my kids play in the yard again.