Small white dots on spinach leaves New Picture

I have seen the same problem reported but no answer was given due to the lack of picture. Spinach looks healthy but it has lots of white dots mostly on the undersides of the leaves. It is most numerous at the bottom of the plants. The white dots feel like salt-like grains when I brush them off with my fingertips. They easily wash off without leaving any discoloration or sign of disease behind. I checked pictures on the net and they do not look like downy or powdery mildew.

What is it and is it safe to eat those leaves that had these white stuff on them? It started showing up on my lettuces, which are in the same bed but not on the same kind of lettuce in a separate bed.

thanks for the help,
Mariann

Image link: Small white dots on spinach leaves New Picture (54 k)

Hi Mariann,

I'm experiencing the same thing with my spinach . . . not lettuce though. We've been washing it away and eating it. I hope it isn't harmful :(

I've never looked at it under magnification. It doesn't seem buglike (aphids, etc.).

I am growing Corenta hybrid spinach variety. I doubt that the white dots would be aphids. I do not have a magnifier but when I look from close they do not look like insects and they do not move around at all. Also they are too nicely almost symmetrically spaced on the leaves and that do not look like aphid aggregation.
I am not convinced that it is not a disease because I let it progress on a few spinach that I did not harvest, and I started seeing small `lesions` when I rubbed off the dots. It also felt gluey on my fingertips while before it was a dry sand-like feeling.

OP said " I let it progress on a few spinach that I did not harvest, and I started seeing small `lesions` when I rubbed off the dots"

Well that's a helpful bit of info.

Look up white rust.

Thanks for the comments from everybody. First of all it is surely not hardened honeydew. I have not seen a single aphid on my plants so far. They have been covered with a floating cover and few insects got under (flea beetles mostly) but not aphids. I checked out pics of white rust and my plants do not look like that at all. I like the exudate from stomata idea though. The symmetrical arrangement of the dots seem to confirm that.
Now I am wondering why other plants would not show the same. I started seeing some on my lettuces but it never got as bad as on the spinach and it was on the upper sides of the leaves where I watered them. So it may be only due to the hard water we have around here???
Eventually, the salt does not do good the plants....at least that is my experience.

Mariann

Yes, I think rhizo gets the golf clap.

Thinking out loud here, I wonder if it is like guttation moisture and the sugars are the residue after evaporation of moisture overnight. That is: the roots are pumping for 45 leaves, and only 10 are evapotranspiring, so more moisture and pressure going thru than needed and the stomata 'leak' under the pressure. The sugars for a couple days could be attracting fungi, bacteria causing the deterioration of the tissue.

I can't find this phenomenon in any of my pathology texts, so just thinking about it from another angle...

Dan

I am having the same problem with my spinach. I looked at the dots under 200x magnification and they are perfect little spheres. I have noticed that the dots do tend to follow the veins and are primarily on the underside of new leaves. To me it looks like sugar. I will try to post pictures later.

I know this thread was from last year, but I was wondering if anyone has come up with an answer. I have the exact same thing on the underside of my spinach leaves this season.

gumshoe- seems like you have a microscope from your post- to actually see the stomata under magnification you can paint 2 thin layers of clear nail polish (let dry between coats) on the under side of the leaf, then use clear tape to pull off the nail polish- this makes a nail polish cast of the stomata that you can then put on a slide. Stomata look like donuts or flat tires under magnification.

Hi,
I am going to tentatively confirm that the white dots are residue left by aphids. I have had this problem on my (unheated) greenhouse spinach all winter and I couldn't figure out what it was. At first, I assumed these were some kind of egg, since they are appear to be tiny spheres when viewed under a magnifying glass.
Now, having read this and other threads and carefully observing the plants for months, I am deducing that it is the aphid residue.
For a while, I didn't think I had aphids but just yesterday I noticed clusters of them way at the base of the plant.

the curious thing is that the small white dots do not appear on the neighboring arugula and parsley plants, nor the collard greens or the rosemary, only on the spinach... Not sure why that would be.

I was thinking the same thing. My spinach is covered in these perfect tiny white dots underneath. not my lettuce, not my basil, just my spinach. I finally saw a few aphids at the very base of a couple plants. I hate them :( Anyone know if it is safe to eat if I wash off the spinach?

Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

If you are a member, please log in.

If you aren't yet a member, join now!

Return to the Garden Clinic Forum

Special Notes for Uploading Images:

You will be asked to designate your image file on the preview page, the second step in posting. You should see an edit box asking for the image file name and a Browse button to the right of it. Click on the browse button to locate the file on your computer.
Image uploads are not enabled for followup messages.
The Subject of your post should describe your image, i.e., "Lilium superbum."
It is illegal to post copyrighted material. Only post images which you have created.
Image files may not be larger than 60 kilobytes.
Images must be either in GIF or JPEG format and have one of the following file extensions: .gif, .jpeg or .jpg
File names containing only letters, numbers, dashes or underlines will work best, such as: "im-1_a.jpg" File names containing special charcters like #, @ or %, may cause problems.
File uploads work with Netscape version 2.0 and above, and Microsoft Internet Explorer 4.0, but they do not work with many of the browsers that claim to be compatible with Netscape, including earlier versions of Internet Explorer.

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

RE: Small white dots on spinach leaves New Picture

Post a Follow-Up