Potato & Lettuce Leaves turning Brown

summer

Hi All, maybe somebody here on this great forum, might know what has happened to my Potato & Lettuce Leaves, as a section of my British Queens, has turned a rusty Brown colour, ( they Potatos were sowed on the 18th March) Now i sowed a second crop of Lettuce, and they also have, which looks the same rusty colour spots, they first crop of Lettuce were ok. They Potato Leaves are getting more and more brown, as the weeks go by, i dont think it is blight, as i have checked under the leaves for signs of blight ,and have sprayed on a regular basis. But i have also noticed that i have an old Rose Bush ( different location from the Potatos) and that also turned brown/yellow, and shed all its leaves, but the roses still bloomed, also some of my Apple Trees, and some of my young Silver Birch, seem to have it as well. Has anybody here noticed any change in their shrubs or plants this year, as i was thinking it may have something to do with climate this year, My location is the Midlands, Hope someone here may help me on this one, with thanks.
I have attached 2 pics of my problem.

Loncey · Posted: Wed Jul 15, 2009 9:03 pm Post subject:

I am growing different types of lettuce this year and have had some problems but I am afraid nothing like that. Perhaps its just the rain has rotted it?
Hope you dont mind me asking a question of my own but I dont think I need to open a new thread and waste space so I apologise for using yours.
I am growing lettuce tintin as it is just for containers and it has flourished cept this week I have notice little brown ,like pebbles on the leaves near the base.Like dirt but a different substance and on the bottom inside the leaves. weird. It had rained,lashed down.
Sorry Summer Smile

michael brenock · Posted: Wed Jul 15, 2009 10:56 pm Post subject:

I think it is not a disease but a deficiency of some sort. It could be a shortage of Nitrogen if your soil is very sandy or a peat based compost caused by too much rain. I don't think it is the same problem on all the plants. magnesium is the other possibility and weed killer damage could produce similar effects. if you have more information on type of soil previous crops etc i would welcome it.
michael brenock horticultural advisor (retired)

summer · Posted: Thu Jul 16, 2009 12:17 am Post subject:

Thanks for your swift reply. The Garden has reasonably good clay type soil, (not peat) with years of farmyard manure dug in, we had not sown in it for many years (maybe 20 years) Then about three years ago, i decided to start again with, Cabbages, Turnip, Onion, Carrot & Parsnips. Then last year, i sowed the same, plus Potatoes ( British Queen) and yes, i had a good crop, no damage to the the crop what so ever, until this year. Now i did sow part of the crop, with some of the my own seed, i saved from last years stock. They only different veg's i sowed this year were, Peas, Lettuce & Scallions, which are sowed at the opposite end, to where the Potatoes are sowed. Now i did try out some of the Potatoes that were under those brown/yellow leaves, and some were twice the size of a golf ball, more were smaller, but were flowery, and nice to eat, so it does not seem to be affecting the quality of the Potato ( maybe growth) But seen the Rose Bush, Apple Tree & Silver Birch shedding, and turning their leaves brown/yellow, i thought it maybe something to do with weather conditions,. No, none of the crops were in contact, with weed killer. Many thanks for your help.

michael brenock · Posted: Thu Jul 16, 2009 10:24 am Post subject:

the symptoms look very like long term damage from residual weedkiller maybe simazine sprayed onto the paths etc. usually when potatoes stay small like yours the quality will be excellent but a poor yield.
The browning of the leaves on trees could be due to wet and windy conditions when growth of leaves is soft. There is no disease that is common to all the types you mentioned and as weather is the only common factor we must only conclude that there is a connection. The growth and recovery in the next few weeks will tell a lot.
michael brenock horticultural advisor (retired)

summer · Posted: Thu Jul 16, 2009 1:38 pm Post subject:

Thank you Michael, for all your help. Just sending a few more photos, to let you see the problem in a wider shot, and also as you can see from the photos, some of the Potatoes, are seen to be ok. Also one photo of the Birch Tree, that also seems to have that problem. Many thanks again.

summer · Posted: Thu Jul 16, 2009 1:45 pm Post subject:

Sorry Michael, those Photos did not send, for some reason. Will try to resend them again.

summer · Posted: Thu Jul 16, 2009 1:56 pm Post subject:

Lets hope they send this time.