I’ve got blackcurrants, planted two years ago. I don’t know the variety but they are supposed to be the larger fruits.
We had a small number of berries last year and they seem to be doing well this year as far as green growth is concerned. However, the leaves have got this disease and I’m sure it will weaken the plant and lower the harvest.
Any suggestions welcome
90% sure there’s aphids on the underside of the leaf. Turn it around and look closely or use a magnifier
Edit: replaced the “lice” with Aphids. Used the wrong word like jcguarneri pointed out
I should have had my glasses on when Iooked. You’re right!
So what do I do about it but organic only?
there is no 1 simple awnser to that question. The closest one thats correct most of the time is.
Let natural predators fix it for you.
Leaving hollow flower stems/leaf litter/mulch. Getting more flowering plants so you have flowers the longest possible time etc will also give you more natural predators.
If also read somewhere spraying a mixture of bakers yeast and sugar water before you have any aphids will attrackt lady bugs to lay eggs so you already have them when the aphids show up.
If the infestation is really bad and you run the risk of loosing a young cutting you can manualy remove them. Or use somthing like soap/alchohol water as a temporary bandage. Those things also kill the benificial inscts. So i would not use them to fast. Or only on a few really bad spots.
a large concept in organic gardening is thinking ahead, instead of doing somthing “innapropriate” and short term “fixing” it afterwards with lots of things.
Build up your benificial insect population. Make sure they have enough food/shelter year round. And a lot of pest problems disapear. Also spread your harvest between many species, so if 1 pest is perticularly bad one year you have “backup” crops.
Dealing with invasive non native pests can be hard though, since they don’t always have efficient predators that eat them around.
@oscar has the right idea. I’d also add that you can easily remove large quantities with a spray of water from the hose. Also, take some time to observe your plants as a whole. Are there ants running up and down the stem? They might be tending the aphids (I’m assuming that’s what @oscar means by lice) and may warrant a targeted remedy like tanglefoot. If your plant’s a little unhealthy (nutrient deficiency, other pests/diseases), it can be more susceptible to sucking insects. Or, sometimes it’s just the healthy fresh growth that they’re getting. That stuff is extra tender for the aphids, and they may be less of an issue once everything starts to harden off.
But unless it’s really bad, nothing is probably the best course of action. But keep an eye on it…
You know they are lice and not mites? My guess is mites. You can use soap spray but you need to do it several times a few days apart. Safer sells an organic soap spray.
dormant oils will suffocate aphids. some can be used in full leaf. read the label 1st. ive been lucky with all the currants i grow ive had little issuses but i still spray dormant oil every spring just in case.
@jcguarneri was right. I could not think of the word, aphids. In dutch we use the word lice for both the human pet and plant pests, even though they’r all different.
It could also be mites (like spider mites)
However every time you treat the aphids or mites you are messing with a natural system. Often there is good reason to. But other times it’s best to keep the aphids around as food for benificial insects.
Benificial insects multiply slowly. Aphids multiply fast. If you don’t feed your benificials you’ll likely not get a high enough population to ward off aphid plaugue’s.
Tropaeolum majus (nusturtium, indian cress) is a plant i sow especialy to get aphids. The aphids love it more than most other plants. So you get aphids really early on in the year. A large enough population to feed the benificial insects. And once you normaly will get your aphid “plaueges” you already got enough benficial insects to avoid the rapid aphid explosion.
This depends a bit on how your climate/weather in the spring is though.
I would handle mites the same way as aphids: do nothing unless it’s severe. Water spray if it is.
No that is aphid damage. Very typical. I have never seen mites on currants. But they can be a problem on currants too (I just looked). Luckily I have not had to deal with them. Damage probably looks the same. So I’m wrong it’s typical. It’s a possibility after researching it a little.
I agree with the water spray it will kill them. Just do it every morning for a few days and they will be gone.
I hate mites, they killed 7 pluot seedlings I had. I take mite infections seriously on seedlings, not so much on mature plants.
It is definately lice (aphids here). Thanks for the great advice, especially @oscar the yeast and sugar water tip.
I’ve cleared them by hand (there were no ants) and I’ll be ready for next year.