This is the leaf canopy for the Musica pole beans. The trellis is 8 foot tall and the vines are over the top and loaded with beans. The top of the canopy looks dark green and healthy but look at the bottom. The leaves are starting to yellow and are mottled. Since taking this photo last week, the yellowing is now half way up the vines, so it spreads fast.
Here is a closer look. The leaf at the top is showing the top surface and the lower leaf is flipped over to show the underside. The leaves are yellow with a mottled pattern.
From what I can gather, this looks like Bean Golden Mosaic virus, something I have never encountered before. It is fatal and all you can do is remove the plants and destroy them. It is not a seed-borne disease, which makes sense because these plants came from the same seed packet I used successfully last year. The disease is spread by insects, most likely aphids or whiteflies. That is puzzling because I generally never see an aphid in my garden. I have Japanese Beetles taking up their favorite dining spot at the top of the vines, but no aphids.
BGM is apparently a major problem in South America, Mexico, and parts of southern US and limits production of bean crops in those areas. Any legume plant can host the disease, including all the clover and vetch I have growing as weeds in the paths in the garden. Serves me right for not keeping up with my weeding. I hope to be able to at least harvest the pods now on the vines, but it does affect pods and I am starting to see signs of that. My Gold Marie bean plants did poorly right from the start but their leaves don’t look this. I don’t know what their problem is but that crop is mostly lost.
That's a total bummer. All that time and effort just to lose them when they should be in full production.
ReplyDeleteOh, that's too bad, Dave. I hope you are able to get at least some sort of harvest before the plants are kaput. I'll have to take a closer look at my pole beans as the Gold Marie have some yellowing leaves at the base of the plant too. I haven't been that great about watering over the past couple of weeks & it's been super hot, so I thought it had to do with that (I gave them a good soaking yesterday). I'm glad you posted the photos as sometimes these diseases are hard to identify, especially if you've never encountered them before.
ReplyDeleteThat is too bad. I used to get rust in my beans, but I never got that. Though my bean leaves do always yellow over time. I swear there are multiple diseases in them. But usually they don't take it out until I get a decent harvest. Some plants really do seem like a race between you and the pest/disease.
ReplyDeleteI had a virus devastate my pole beans and snake beans, this year.
ReplyDeleteDevastating type of disease which makes me a bit depressed about gardening.
Oh, that is bad luck! I have had some mosaic problems with my squash plants and it is heartbreaking when you get so excited about your plants and potential harvest just to have it snatched out from under you. I hope you get some beans from them.
ReplyDeleteAs I saw the first picture, I was thinking of commenting on the great vertical growth you have ... I really need to work on good trellises for my gardens. But sad news ... hope you can save what is there!
ReplyDeleteHope you manage to get a decent crop of beans before the virus destroys the plants.
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