Diagnosis?

[geeme]

I regularly put my seedlings in the south-facing window at the front of my house - it has been too cold to take them outside yet. However, we actually had a sunny day up to 72F the other day, so I hauled them outside for a bit. All of the peppers came back as happy little buggers. However, my single tomatillo plant didn't come back so well. Well, I didn't look closely at it until the next day, and found "loverly" bumps on some of the leaves, and bumps down the stem a way. The next two shots are of the leaves, same angle (camera on a tripod), but with different lighting - first with a flashlight held to the side, second with no lighting other than the room light. The bumps have the appearance that someone tried to push something into the leaf from the back side - the back is hollow under the bumps, not flat. Most of the bumps are "just" bumps, but some (when looked at under a jeweler's loupe) appear to have the upper leaf surface open - almost like a blister that's been burst.

The stem has some little white-ish bumps on it. When examined with the jeweler's loupe, these have more of the appearance of a small pimple - they are clearly not bugs simply sitting on the stem. I ran my fingernail over one, and it kind of behaved like a pimple, too - it broke the surface and a bit of plant juice came out - so it's not like I simply moved a bug. My apologies for the quality of the stem pics, but these are the best I could get.

My first thought was sun-scald. I haven't eliminated this as a possibility, but it seems odd that it tolerated the front window fine for several more hours than it was outside, especially given that none of the peppers came back like this - I have 28 pepper plants at different stages of development that went outside with it, so it would seem at least one of them would have had similar results if it was sun scald. However, I also recognize that tomatillos aren't peppers - maybe there's something in that.

At any rate, if you've seen something similar and have some insight, I'd appreciate hearing what you think it might be.

G

 

[Pepper Ridge Farm]

Edema in plants is the extended swelling in plant organs caused primarily by an excessive accumulation of water. This occurs since the cell walls are composed of flexible cellulose.

 

[Nova]

I think PRF is spot on the money here.

 

[geeme]

My link < This article from UMass indicates edema causes raised bumps on the underside of the leaf, which seems to be opposite of what the tomatillo has. Am I reading the article incorrectly, or is this potentially just because it's a different variety of plant?

 

[srin2]

mite might cause that also.
This common mite species also causes spot-like deformations on aspen leaves, but the galls are located on the lower surface of the leaf. The tiny mites live among short hairs that protrude from the shallow "cups" on the leaves.

Galls induced by Phyllocoptes populi are small pale swellings on the upper surface of the leaf. By contrast, Aceria varia galls (the one on the lower right-hand side of this leaf) are reddish-brown and hairy on the upper surface, and the "cup" projects downwards.

 

[geeme]

Blurgh - that does look more like my leaves than the pics of edema which I've found.

 

[RedtailForester]

If I were to make an educated guess, I would say something more along the lines of what Srin wrote.

 

[srin2]

from what i read in the other post you made . this was the only surviving tomatilo plant from the broad mite attack.....could be them again ? or a secondary fungus infection cause by the mites.

 

[geeme]

I'm more inclined to think that it's mites, as well, in part because I abuse my plants - no over-watering going on here. Also, the cupping described about the mites is consistent, and its being variety-specific would fit with it not affecting the peppers. However, can edema cause similar cupping, or would the back always be more flat (rather than indented) if edema? Also, can edema occur with an absence of over-watering, such as due to fertilizer use, or such? I'm reading that a variation in temps between the roots and the stems/leaves can create this, but over-watering still seems to be a factor in such cases.

And if we say it's mites (or gall midges), I'm finding a life cycle of about 2 weeks, give or take. Does that sound about right? Do we think this plant can be saved if I start with a routine of insecticidal soap?

What about treating edema? I have a space heater in the room the plants are in, have flouro lights on the plants, and run a fan a few times a day, but the plants are not right in front of the space heater. (The room is not "very" warm.) Days that are screamingly sunny, the plants go to the front window, where the sun coming in warms them up significantly for the duration.

I can see treating for both, just in case. Your thoughts?

 

[geeme]

from what i read in the other post you made . this was the only surviving tomatilo plant from the broad mite attack.....could be them again ? or a secondary fungus infection cause by the mites.

No, definitely not the same symptoms as the broad mites. The broad mites suck the juices out of individual cells, and progress to the next cell when one is empty - you'll first find what looks like a small hole, then it just keeps getting bigger and bigger, until the leaf/plant gives up. In fact, it's not actually a hole, as the outer structure of the leaf remains (it's just empty now, so is rather transparent.) It does not cup the leaf at all. A secondary fungus infection is a possibility, though I periodically mist the leaves with chamomille to hopefully prevent that.

 

[geeme]

End of Thread.

Sprayed insecticidal soap on it, apparently way too late. The increase in damage between yesterday and today was phenomenal, so it is now in a sealed bag in the outside garbage can - in the end this was clearly bug damage. Poor plant! Well, so now the question - did the bugs arrive while it was outside, via a flying insect, or did they come in the soil? Time should tell, as I've got two more that sprouted on Monday.