Author Topic: Black spots on pea leaves  (Read 504 times)

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Offline pinefamily

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Black spots on pea leaves
« on: April 29, 2017, 02:49:48 PM »
I have some of my pea plants with black spots on the leaves, both green peas and sugar snap peas. Is this a pest or some sort of disease? I have read up on pea blight, and from the description and photos, doesn't seem to fit the bill. It has only come on after some recent rainfall.

Offline Grub

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Re: Black spots on pea leaves
« Reply #1 on: April 30, 2017, 06:22:39 AM »
I get it all the time, I suspect fungus disease. My mum told me that it's from too much rain when the peas are young and/or soil which is not draining properly. So I'm going to try peas in free draining mix next year without leaf mulch.
Cool region, Canberra. Courtyard and balcony gardener.
http://actgarden.blogspot.com/

Offline pinefamily

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  • Mid North SA; warm temperate climate
Re: Black spots on pea leaves
« Reply #2 on: April 30, 2017, 08:11:57 AM »
Thanks Grub.
We have had a lot of rain (for us anyway), and they are only young seedlings. Should I leave them, or pull them out? They are all in raised garden beds with a 50/50 sandy loam, enriched with compost and manure.

Offline Grub

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Re: Black spots on pea leaves
« Reply #3 on: April 30, 2017, 12:08:58 PM »
I think in your climate you have time to start again. In my experience they didn't do that well, although they still produced, but the fungus spreads upwards at least as fast as they grow. Doesn't seem to affect the pods if they are already flowering. I'm probably going to start mine in toilet rolls this spring or under cover.
Cool region, Canberra. Courtyard and balcony gardener.
http://actgarden.blogspot.com/

Offline Troppo

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Re: Black spots on pea leaves
« Reply #4 on: April 30, 2017, 12:29:23 PM »
We commonly see it on our field peas. Have a look at this thread. I made a few comments about how farmers deal with it and the basics can be applied to home gardeners. Basically crop rotations and removal of old pea stubble. Once you've got it it. Eat to remove those plants. Commercially growers spray with fungicides to control/minimise the effects.

http://www.ozgrow.com/index.php/topic,12259.0.html
Cold winters, Hot summers - Goondiwindi, QLD - Backyard/Amateur Breeder

Current Breeding Projects:
Red sweet corn... Heat tolerant tomato... Purple snow peas... Improved spaghetti squash

Offline pinefamily

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  • Mid North SA; warm temperate climate
Re: Black spots on pea leaves
« Reply #5 on: April 30, 2017, 02:11:58 PM »
Thanks Troppo and Grub. Had another look today, and seems to have spread to all of them. Definitely not in the soil, as the beds are newly set up. I'll pull them up and start again. It's a bugger because they were all looking so healthy.

Offline Templeton

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Re: Black spots on pea leaves
« Reply #6 on: May 03, 2017, 08:27:55 AM »
I tried a slightly different approach this season.
Since i think it came in on pea straw mulch, no pea straw. At the first appearance, i sprayed with EcoFungicide - potassium bi carb. Didn't do much. I then sprayed with copper oxychloride, a week or two later,and followed this up with a couple of hours of picking off the infected leaves, which were very close to the ground - oh my back! Seems to have held it in check, at least enough for the plants to outgrow it. flowering at the moment, so will see how pod development goes. The leaf removal seemed to be most successful, but given varietal differences, different beds, and the two spray treatments, and variable wet and dry spells, hard to tell.
It does effect pods if you leave it to run long enough.
T

Offline pinefamily

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Re: Black spots on pea leaves
« Reply #7 on: May 03, 2017, 07:50:09 PM »
I've pulled most of the seedlings, and sprayed the couple that weren't too bad with neem oil (suggested by my local hardware bloke who is also very much into organer ic gardening. Also planted more seeds. Fingers crossed we don't get more torrential rain.

Offline Grub

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Re: Black spots on pea leaves
« Reply #8 on: May 03, 2017, 10:38:16 PM »
I think powdery mildew might be on the pea straw but the dark spots I think are other fungal diseases. I think this is the risk with autumn plantings and the cold/wet weather. I haven't had much success with them and we get so many frosts that tend to mottle the pods anyway that I can only really do spring plantings. On the plus side my very late started beans (I think I planted these in Feb) are doing great - of course, they will not handle successive frosts. But whatever grub was being laid on them by wasps or moths and then boring into the pod is obviously gone this time of year.
Cool region, Canberra. Courtyard and balcony gardener.
http://actgarden.blogspot.com/

Offline pinefamily

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  • Mid North SA; warm temperate climate
Re: Black spots on pea leaves
« Reply #9 on: May 11, 2017, 09:55:54 AM »
I checked what mulch I am using at the moment.  I thought it was pea straw but it's sugar cane mulch. So much for paying attention, lol. Still waiting for the new seeds to pop up. The remaining seedlings that I sprayed are looking ok, and I pulled any leaves with the black spots. Fingers crossed.

Offline Templeton

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Re: Black spots on pea leaves
« Reply #10 on: May 11, 2017, 07:39:25 PM »
had a quick look at my peas before work this morning, and it looks like at least one of my red snows is resistant to black spot. good news, The consolation of disease is the opportunity to select for resistance - at least in a diverse garden.
T