Why are my pea plants turning white?

[Colin_M]

These are Alderman climbing peas and have grown to about 6 feet high, currently with a lot of pods on them but hardly any more flowers.

I have been watering and feeding them regularly. Any reason why the leaves etc are turning from green to white, or is the lack of new flowers a sign that they've decided to pack it in and that's my lot?

I have some of JB's climbers sprouting but it will be a week or so before they're ready to sow as I thought this lot would last a little longer. How much longer after I've picked the last peas should I persist?

[oldherbaceous]

Dear Colin, i don't know what sort of preparation you made before your peas went in, but these tall varieties need a good poltice of compost manure and anything else that will hold on to moisture and release food over a long time.
It really does sound as if your peas have exhausted the ground they are in.

[John]

Hello Colin
If you can rub the 'white' off then I'm afraid its powdery mildew affecting your peas. Its a bit early in the season for it but this very warm and humid spell of weather may have brought it on.
The only way I've ever managed to avoid it is to use very early varieties.

John

[Colin_M]

Thanks chaps, in answer to your questions:

OH - They are in a 2 parallel rows about four feet long. I dug a trench around a foot deep between these to start with and filled it with manure to a depth of around 6 inches, then covered with soil. They have also had some Tomorite around 3 times in the last month.

However if despite the above it's just lack of food, that might be possible to address. Please advise (before I pour more fertilizer on them) if this isn't the answer.

John - no, it's not on the surface. The colour of the leaves & stems has slowly changed from healthy green to paler then almost white. This coincided with a heavy crop of peas, them reaching around 6' high and no more flowers appearing.

Any more ideas or should I just harvest what i've got and plant some more for a second crop in a different spot?

[bunuel]

Hey Colin,

I am having the same issue with my peas. I just presumed that they had exhausted their growth for the season and was going to rip them down and plant something else. I have a second batch growing around sweetcorn at the moment so I'll be interested to see whether or not they have the same fate.

cheers,

Fraser

[andys]

Hi Colin,
As others have diagnosed it must be powdery mildew, this usually occurs when we have a period of warm dry days and cool nights and the soil drys out.
I had a bad infestation 6 years ago this month following a warm dry windless spell and it travelled from one row of Onward to other rows of peas within 5 yards so if I were you I would pull the affected Alderman plants and burn them before the fungal spores travel around your plot.
Good luck,

Andy S.

[Colin_M]

Just to let you know I believe the answer to this may be a combination of:
1) The peas using up the available nutrients.
2) Insufficient watering over the last 2-3 weeks.

I haven't watered them as much as I would do French Beans or Runners - only once every 2 or 3 days, whish I suspect wasn't enough during periods of +30 C for several days on end.

As a result, even though there was manure in the trench next to them, the ground may have been too dry for them to make full use of this.

I've tried an experiemnt now, watering them every day and also putting a can of tomato feed on one end of the row a few times a week - that should allow us to see which makes the most difference.

ps - Andys, I'm pretty sure it isn't mildew as there's no coating on the surface. I did a quick Google and most of the pictures of powdery mildew show patches of white - see here for example. By comparison, on my plants, the whole thing (stem and 100% of the leaves affected) have gone white. If I get organised, I will try to take a picture & show you.

[oldherbaceous]

Dear Colin, it's a real job to get them to respond once they have got to this stage, as they will be desperately trying to fill the pods.
But once you have picked a lot of the peas, you might find they will show some regrowth.

A deeper trench filled with more goodness, will go a long way to solving this problem another time.

[Colin_M]

Thanks OH. Guess I need to start them off differently next time.

The funny thing is that I've dug the trench of compost/manure before for Runner beans, but never peas. In addition, I've grown both climbing and ordinary peas before without much if any extra "nourishment" and they've been ok.

Anyway, 'suppose it's all part of the learning process.

[Johnboy]

Hi Colin,
Peas appreciate a good amount of compost under them. In the days when all the family were home there was so much vegetable waste that I used to prepare next years pea bed with uncomposted material a bucket at a time down a trench dug as you go. It would work out to about two bucketsful per foot run of the trench. Peas simply thrive on this.
JB.

[andys]

Hi ColinM,

Regarding the powdery mildew photo's they are just a very mild showing of the problem, when I had a bad infeststion in July 2003 the whole of the leaves, pods and stems became covered within 7 days of it first showing.
You could try spraying with Dithane 945 to see if that gets rid of the spores.

best of luck,

Andy S

[chrisyorkshire]

Sorry to pour cold water on some of your theories. There are 5 of us on our small yorkshire allotment. It seemed that overnight all of our pea plants turned white at the top across all allotments. We all use different sources of manure, we were all growing different varieties - I was growing several varieties at different stages of growth - they all turned white at the top of the plants. Odly although in some cases the white seems to have gone back to green the plants appear to have virtually stopped growing at this point. The ones just throught the ground havenly moved since. Most of the others have not produced the normal number of pods if any. We are all very suspicious. We are all experienced allotment gardners we've not seen this effect before. This is nothing like mildew its a totally white bleached plant as white as the flowers. Interestingly a couple of adjacent broad bean plants went totallly white at the top as well. We suspect some sort of insecticide or worse! There is a large crop of maize in the next field gwon by the new plastic sheet technique and we are even wondering if that has some sort of insecticide built in? We've also heard rumours of someone who has a relative in Wales also an experencing identical problem. Maybe one for KG to ask question about in the magazine to see if this is a widespread problem?

[alan refail]

Hi Chris

You may have hit on something here - and it sounds scarily reminiscent of the aminopyralid problem of last year, though quite different in transmission presumably. There's a large range of pre-emergence herbicides marketed for use on maize under plastic. A google search for "maize pre-emergent herbicides" should bring up some names such as the new Cadou Star from Bayer.

I assume these products are sprayed on the land making spray drift possible.

Just a guess, but it might be worth looking into.

Alan

[alan refail]

Since my last post I have been reading up on Cadou Star. Have a look at Bayer's Product Summary.

What interested me was this line:

Mode of Action
Isoxaflutole is a bleacher, Flufenacet is a cell division inhibitor


Interesting.

[Colin_M]

There are 5 of us on our small yorkshire allotment. It seemed that overnight all of our pea plants turned white at the top across all allotments.

Hi Chris. Do you mean that the peas at the top of the allotment all turned white....or that just the tops of the pea plants grown by you and your mates went white....

Sorry to be pedantic but if it was the first example, that's like mine. It wasn't just the top of the plant, it was pretty much the whole plant. Now the only thing is that there's no commercial maize being grown within a mile or so of us. In addition, a few of the plants at one end of the row stayed green (and are still green).

Having said that, the guy on the next allotment plot does like his chemicals. However he has a line of ordinary peas just down from my climbing peas and his have stayed green .