[greengiant]

Hi all,
Apologies if I'm just adding to to an exhausted topic, but even after looking over other photos on the forum, I still can't decide if my Maris Peer have blight or not. There is no white mould on the leaves' undersides - does this mean I'm in the clear? Also, many of the lower leaves have turned yellow. If it's of any help - it's been extremely windy in my area (Kildare), sunny and wet. See photos below. Advice asap will be gratefully received!

[Lius]

Hi greengiant, are you the "Jolly......."?

I have had the exact same damage to the foliage of my first and second earlies and the second earlies did not even flower. I did not spray either crop and both had perfectly normal tubers; however the quantity and size of the tubers was down on last year, I suspected a low yield as the foliage did not grow very big this year. I am still harvesting second earlies with the same foliage damage which are fine, they are Orla (blight resistant) and I'm not going to spray.

Strangely though, my main crop Sarpo Mira (also blight resistant) shows no sign of this damage, in fact they look extremely healthy, with deep green leaves, and the bright flowers started to blossom this week. The foliage on these are small but it's early days yet and I'm hoping for a good harvest from the main crop.

[sirpsycho]

I've the exact same thing on my queens, just on a couple of plants. I pulled one last night and everything was well in order. Like Lius, my plants didnt get very big and I never noticed the flowers but the spuds are all spotless and decent size. Not a massive haul but I got about 6-8 decent sized spuds from it and they tasted grand.

[greengiant]

Sorry for delay in getting back. Thanks for the comments. Potatoes seem fine - dug up one plant & got 17 nicely sized & perfectly formed spuds, tasted nice too!

[tippben]

I had exactly the same infection on my Orlas. I eventually identified it as Alternaria solani. It's different to the classic "famine" blight Phytopthera infestans. Maybe Orla is more susceptible to the former and not the latter? I cut and removed the haulms, and still have a decent crop, apart from some slug and wireworm damage. My tomatoes were luckily not infected.

[paul23]

Yeah, had something like this last year too. Didn't affect the potatoes at all as far as I could tell, but it had me worried for a bit.

[michael brenock]

the yellowing of the leaves is not a disease but a physiological upset caused by the interaction of weather and nutrients The potatoes had tubers formed by a certain date and the plant was able to bring that number to maturity The potato plant went into the senescence stage no longer producing hew roots or leaves the nutrients were withdrawn from the leaves into the developing and ripening tubers. The alternative would have been a spell of second growth where the tubers develop knobs and uneven swellings. The warm month of April would account for a lot of these unusual colourings. Second growth has the bad effect of upsetting the flavour and "flouriness" of the tubersi .
michael brenock horticultural advisor (retired)