What are these leaf spots?

Controlling pests of bamboo

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Alan_L
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What are these leaf spots?

Post by Alan_L »

Some of the leaves on one Indocalamus tessellatus are getting these spots:
Ind_tess_leaf_spots-1.jpg
Are these just leaves that are going to turn yellow (well, almost orange in the case of this species) and drop? Is it sun burn? Something else?
bamboothew
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Re: What are these leaf spots?

Post by bamboothew »

I have been wondering the same thing. I have several phyllostachys showing those spots and some apparent leave burn as well, like your tessellatus. 3 of the phyllos are potted so I have been keeping them quarantined, but cannot find any signs of insects so perhaps it is environmental. Been wondering if it is some nutrient deficiency, perhaps? I say this because the worst plants by far are the potted ones so maybe I have leached something out by watering them almost every day all summer?
God Bless,

Matthew

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Genesis 2:8 And the Lord God planted a garden eastward in Eden; and there He put the man whom He had formed.
Tarzanus
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Re: What are these leaf spots?

Post by Tarzanus »

Similar if not the same problem with my Moso seedlings.
Some parts look the same as yours, and some have scattered spots like these on photo below. There are no mites, no aphids, no other hungry critters visible on any of bamboos. I've been connecting this with morning fog, we've had lately, but it can be something else. Few of bamboos showed something similar earlier when temperatures were still high and humidity relatively low.
Did any of you water it during the day sprinkling it over foliage? Was the soil ever too wet? I have no idea what could cause such leaf burns, I also considered if it could be some kind of pollutant in the air that mixed with mist or fog and then damage the leaves.
Image

PS: Fargesia Murielae is not affected by it. Only noticed it with Phyllostachys bamboos. The more sheltered they were, less affected they seem to be.
bamboothew
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Re: What are these leaf spots?

Post by bamboothew »

Tarzanus, my affected plants have only been watered directly on the soil and mostly in early morning or late evening, very rarely do I water during the heat of the day. The three most affected plants are 2 potted nigras and a potted moso. On those plants almost if not every leaf is affected. Forgot about the potted nidularia division, it has just a few mildly affected leaves, and have noticed just a few leaves mildly affected on various other phyllos. It has been one of the hottest summers on record here with almost every summer day in the 90's, so I wonder if it could be heat related? It makes sense that extreme temps would affect potted plants more, perhaps. Luckily, none of the heavily affected plants are very crucial (already have specimens in the ground), though they are very nice divisions, so it's not such a huge deal if they don't recover but I wonder was causes it and how it can be prevented. Hopefully they look better at some point after the leaves get replaced. Hopefully someone here knows for certain what the problem is with these plants.
God Bless,

Matthew

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Genesis 2:8 And the Lord God planted a garden eastward in Eden; and there He put the man whom He had formed.
bamboothew
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Re: What are these leaf spots?

Post by bamboothew »

Just thinking out loud here: I was just outside looking thoroughly at most of my bamboos looking for this issue. I did the same thing about 2 weeks ago since I was concerned about what this issue could be, and at that time the potted divisions of nigra had already been affected for a good many weeks. What I am seeing today is that there are just a few leaves on a great many phyllos and also on Arundinaria gigantea and pleioblastus argenteostriatus that exhibit these spots and the yellowing. A couple of weeks ago they were absolutely not like this, so my current theory would be that perhaps the spots could be a part of the natural seasonal leaf drop triggered by temperature change (though I didn't notice this last year) and maybe the potted divisions have been affected earlier and more because they are getting rootbound (leaf drop can be caused by drought, and drought can be simulated in a rootbound pot even if it is watered often, would be my guess). Certainly if not for the spots, the yellowing going on with odd leaves on the in-ground plants would cause no alarm, since I would assume it was only seasonal leaf drop. Just my thoughts, I am only a novice making half-educated guesses :) There are a couple of feral phyllo groves I can stop by today and see if they are doing the same thing. My guess is that they are, and if so I will feel better knowing that my plants probably aren't sick!
God Bless,

Matthew

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Genesis 2:8 And the Lord God planted a garden eastward in Eden; and there He put the man whom He had formed.
Tarzanus
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Re: What are these leaf spots?

Post by Tarzanus »

Keep us informed, please. :)

Strange with the leaf on picture I've attached earlier is, that it didn't change a bit. It did not get more yellow until now and we've had quite a few mornings around 2C (first frost should be here in a couple of days too).

I'm new to bamboo growing and I don't feel happy to see their leaves like that. I'll experiment a bit more next year and keep them away from full sun. At least part of them, this year I have a feeling, they got a bit scorched. Seedlings and young divisions are not as hard as larger/older plants. :?
Tarzanus
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Re: What are these leaf spots?

Post by Tarzanus »

Bamboothew, one other reason could be the cause that Phyllostachys nidularia didn't show such signs. Like heteroclada it can tolerate soil that is too wet. I kind of doubt that but my bamboos did show some shock that could be related to that in the beginning of spring when we've had rain all the time, and they never really recovered. The worst thing is, hot weather started after that with almost no rain until now. It could be either root damage from too much rain and damage because of heat and strong sunlight. I have to be more systematic next growing season, to eliminate some possibilities. :D
bamboothew
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Re: What are these leaf spots?

Post by bamboothew »

I went by a vivax grove and a grove of yellowgroove yesterday and both groves had occasional leaves with those symptoms so I wouldn't count it as anything so unusual, perhaps it is just related to seasonal leaf drop. My potted divisions with almost every leaf that way, though, I believe must be severely stressed in some way, maybe they are very rootbound. One of them has an escaped rhizome already from a 3 gallon pot and it was a tiny division back in late spring. I really doubt that I have overwatered them, but I guess that is possible too, but I watered all of my potted divisions (several species) with the same frequency and the nigra is the only one suffering. Will need to unpot them and see what is going on, perhaps all the soil is already gone :) Nigra seems to be an extrememly vigourous runner here for me so far, anyway!
God Bless,

Matthew

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Genesis 2:8 And the Lord God planted a garden eastward in Eden; and there He put the man whom He had formed.
Alan_L
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Re: What are these leaf spots?

Post by Alan_L »

So nobody knows what causes this?
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needmore
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Re: What are these leaf spots?

Post by needmore »

Are any of the plants that exhibit this NEVER watered by municipal water supplies? Conversely, does anyone see this on plants they've never watered?
Brad Salmon, zone 12B Kea'au, HI
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bamboothew
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Re: What are these leaf spots?

Post by bamboothew »

needmore wrote:Are any of the plants that exhibit this NEVER watered by municipal water supplies? Conversely, does anyone see this on plants they've never watered?
The feral groves I checked wouldn't have been watered by any municipal water supply and both groves exhibited symptoms.
God Bless,

Matthew

===============================

Genesis 2:8 And the Lord God planted a garden eastward in Eden; and there He put the man whom He had formed.
Alan_L
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Re: What are these leaf spots?

Post by Alan_L »

needmore wrote:Are any of the plants that exhibit this NEVER watered by municipal water supplies? Conversely, does anyone see this on plants they've never watered?
I see this only on the one tessellatus which is planted in a raised bed that gets more sun. It probably dries out pretty fast. It's just 10' from another tessellatus in a big pot that gets a little less sun and doesn't show these spots. Both were watered by municipal water equally, although the potted one probably got a little more attention. It only seems to be on the side of the plant that gets the most sun.

I'm not really concerned about it, just curious. It's ugly, but at least it only showed up late in the season.
Tarzanus
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Re: What are these leaf spots?

Post by Tarzanus »

Alan, I've noticed the same thing, but there are some spots on semi shaded seedlings too. There's one aurea (most likely, I'm not 100 sure) from rhizome division that is getting full sun and also shows almost no sign of this problem. That is an in-ground bamboo, so it might not be affected as those in pots were. During the summer, it curled leaves perhaps 10 times, compared to potted bamboos that showed that during half of the summer. The most affected are bamboos that get early morning sun (SE).
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