Help with leaf issue ID - could this be russet mites?

MSchep · June 24, 2020

Hi All,
Seeking some help identifying what is going on with these lower leaves on my sungold plant. This is an issue i usually see every year a little bit later in the season, but spreads pretty steadily. I've never really figured out what it is or how to treat. Early this season, I read some of the threads here on russet mites, and I've been wondering if that is actually the problem I've been having?

Several leaf pics follow of troubled spots I've just removed from the plant, the first two are the same leaf, top and bottom. I added a close up of one of the cut stems for good measure, though I don't see anything there.

Thanks in advance for your thoughts...

zipcode · June 25, 2020

It doesn't really look typical. The stems around the affected areas should get a slight bronzed look, also the leaf petioles, that's the most classic indicator (it's already somewhat advanced at that stage).
Take a look with a good magnifier at good parts of the leaf (like the good leaf tip of an affected leaf). A wide angle lens reversed makes for a good magnifier for example (must get really close to the sample with it).

MSchep · June 25, 2020

OK thanks, good to hear that this doesn't immediately strike you as RM. Haven't been able to locate anything I can use to magnify, but will keep trying.

Do you have any thoughts on what this problem is if we rule out the mites?

zipcode · June 26, 2020

Not really, no.
There are certainly suspicious signs for russet, like those leaflets being first affected on a leaf, so keep a good eye for those bronzed stems/petioles.

Shrinkrap · June 29, 2020

Could be thrips. Western flower thrips and spider mites hang out together in my neck of the woods. I've researched them quite a bit, so I could be delusional.

The was one of my plants ts a few weeks ago that developed TSWV, the next is a plant from last year, with the bottom showing the yellowing that plagues me each year, and the third has both thrip damage and "aphid casts".

https://laidbackgardener.blog/2015/1...thrips-attack/

UC ANR Blogs...not saying you need to worry about TSWV
https://ucanr.edu/blogs/blogcore/pos...?postnum=42820

"What's causing the spots on the leaves of my tomato plants?" (Redding, CA)

https://www.redding.com/story/life/2...ps/5272282002/

MSchep · July 2, 2020

Thanks Shrinkrap. I have had some thrips this year, but most of the problem has been with neutering my pepper blossoms before they set. The affected pattern on my leaves does look more like your third pic. I don't seem to have any that look like a more scattered scarring like your first pic, and most of the pics in your linked articles. Mine all seem to start from one or two spots and slowly expand radially out to the rest of the leaf from there. I'll try stepping up my pyrethrin treatments to see if it helps.

Out of curiosity, how from from Los Gatos are you?

Shrinkrap · July 4, 2020

"Out of curiosity, how from from Los Gatos are you?"

Far enough to not be sure where that is!

I'm in the last bit of Solano County; half way between SF and Sacramento. Practically Central Valley, except for the cost of living.
Los Gatos is South Bay? Maybe 90 miles but SOO many micro climates.

MSchep · July 4, 2020

Yep, about 10mi due south of the SJC airport. And you're right, would probably pass thru 200 different microclimates on my way to you. LOL

July 4, 2020	#7
Shrinkrap Tomatovillian™ Join Date: May 2006 Location: N. California Posts: 701	"Out of curiosity, how from from Los Gatos are you?" Far enough to not be sure where that is! I'm in the last bit of Solano County; half way between SF and Sacramento. Practically Central Valley, except for the cost of living. Los Gatos is South Bay? Maybe 90 miles but SOO many micro climates. Last edited by Shrinkrap; July 4, 2020 at 12:11 AM.

June 25, 2020	#2
zipcode Tomatovillian™ Join Date: Jun 2010 Location: Romania/Germany , z 4-6 Posts: 1,582	It doesn't really look typical. The stems around the affected areas should get a slight bronzed look, also the leaf petioles, that's the most classic indicator (it's already somewhat advanced at that stage). Take a look with a good magnifier at good parts of the leaf (like the good leaf tip of an affected leaf). A wide angle lens reversed makes for a good magnifier for example (must get really close to the sample with it).

June 25, 2020	#3
MSchep Tomatovillian™ Join Date: Mar 2016 Location: Los Gatos, CA Posts: 70	OK thanks, good to hear that this doesn't immediately strike you as RM. Haven't been able to locate anything I can use to magnify, but will keep trying. Do you have any thoughts on what this problem is if we rule out the mites?

June 26, 2020	#4
zipcode Tomatovillian™ Join Date: Jun 2010 Location: Romania/Germany , z 4-6 Posts: 1,582	Not really, no. There are certainly suspicious signs for russet, like those leaflets being first affected on a leaf, so keep a good eye for those bronzed stems/petioles.

July 2, 2020	#6
MSchep Tomatovillian™ Join Date: Mar 2016 Location: Los Gatos, CA Posts: 70	Thanks Shrinkrap. I have had some thrips this year, but most of the problem has been with neutering my pepper blossoms before they set. The affected pattern on my leaves does look more like your third pic. I don't seem to have any that look like a more scattered scarring like your first pic, and most of the pics in your linked articles. Mine all seem to start from one or two spots and slowly expand radially out to the rest of the leaf from there. I'll try stepping up my pyrethrin treatments to see if it helps. Out of curiosity, how from from Los Gatos are you?