diane
New Member
Posts: 7
|
Post by diane on Apr 12, 2015 14:59:44 GMT -8
I am growing a number of potato seedlings in my greenhouse, some from seeds I've bought this year and two lots from o p seed from last year.
They are fine except for several Fiesta Gold o p seedlings which have clusters of tiny green bumps on the upper leaf surface. What causes this?
Diane Victoria British Columbia, Canada
|
|
|
Post by DarJones on Apr 12, 2015 17:46:04 GMT -8
Diane, can you post a picture?
|
|
|
Post by Tom Wagner on Apr 12, 2015 20:47:46 GMT -8
I, too, would like to see a picture. I think of galls and types of fungal pathogens but.....
|
|
diane
New Member
Posts: 7
|
Post by diane on Apr 13, 2015 7:42:52 GMT -8
The small green bumps flatten and turn brown. Attachments:
|
|
|
Post by Tom Wagner on Apr 13, 2015 23:48:58 GMT -8
I wonder if there are any diagnosticians within county extension offices who would look at these photos and suggest something?
|
|
diane
New Member
Posts: 7
|
Post by diane on Apr 14, 2015 8:01:24 GMT -8
If it happens again, I could take the leaves along to the nearby federal Centre for Plant Health quarantine station. The leaves I photographed are all squished at the bottom of a bag of garbage so they wouldn't be suitable.
|
|
|
Post by DarJones on Apr 14, 2015 8:12:37 GMT -8
That is consistent with damage from thrips. You might check carefully for tiny black beetles. They jump off the leaves at the first sign of movement so you have to look hard to find them.
|
|
diane
New Member
Posts: 7
|
Post by diane on Apr 14, 2015 19:51:48 GMT -8
I'll look tomorrow. I am not familiar with thrips except for their name. Where do they hide when they're not chewing plants or sucking them, or ....?
The area is one foot by two feet and there are about 60 plants. Two leaves on a plant at one end and two on a plant at the other end got the bumps, but none of the others did, and neither did any of the other kinds of seedling potatoes on the same table. Does this seem like thrip behaviour?
|
|
diane
New Member
Posts: 7
|
Post by diane on Apr 24, 2015 18:40:46 GMT -8
Well, I haven't seen any little black beetles. However, the problem is not specific to potatoes. I now have the same thing on a couple of pepper leaves, and the leaves on a Tibouchina - a semi-tropical shrub that I bring inside for the winter. That is probably where it originated.
|
|
|
Post by Tom Wagner on Apr 26, 2015 7:19:39 GMT -8
Thrips are usually the bugs I see when I am pollinating potato flowers. They crawl all over the anthers within the flower and I think they actually aid in help self pollinate some varieties of potatoes.
|
|
diane
New Member
Posts: 7
|
Post by diane on Apr 29, 2015 16:27:17 GMT -8
OK. I'm happy to report it is a physiological problem. That explains why I never saw any insects.
It is edema. Cool, cloudy conditions, high humidity and excess water promote it. The roots take up more water than can be transpired through the leaves. Leaf cells swell and burst, causing blisters and small lesions.
|
|
|
Post by Tom Wagner on Apr 30, 2015 0:47:11 GMT -8
|
|