late blight in 2010?

[tjg911]

i'm wondering what is the likelyhood of this year's extensive late blight occurrence in the northeast likely to cause it to resurfacing next year?

i wondered if it overwintered in the soil or on trees or grass - in other words can we expect this to be wide spread again in 2010?

i found this so i suspect the answer is no or is this information incorrect?

"Late blight is caused by the fungus Phytophthora infestans. Unlike most pathogenic fungi, the late blight fungus cannot survive in soil or dead plant debris. For an epidemic to begin in any one area, the fungus must survive the winter in potato tubers (culls, volunteers), be reintroduced on seed potatoes or tomato transplants, or live spores must blow in with rainstorms. Disease development is favored by cool, moist weather. Nights in the 50's and days in the 70's accompanied by rain, fog or heavy dew are ideal. Under these conditions, lesions may appear on leaves within 3-5 days of infection, followed by the white mold growth soon thereafter. Spores formed on the mold are spread readily by irrigation, rain and equipment. They are easily dislodged by wind and rain and can be blown into neighboring fields within 5-10 miles or more, thus beginning another cycle of disease."

from http://ohioline.osu.edu/hyg-fact/3000/3102.html

tom

[tjg911]

and now that you read that i wondered if covering the surface soil with deeper soil to bury any spores in the surface soil where a lb infected plant was removed was going to inoculate the soil with the fungus? again i think the answer is no if that information is correct.

tom

[tjg911]

comments please.

tom

[hasshoes]

I think I read somewhere it needed ot be buried by two feet.

[Sherry_AK]

Originally Posted by tjg911

Disease development is favored by cool, moist weather. Nights in the 50's and days in the 70's accompanied by rain, fog or heavy dew are ideal.

I don't know the answer to any of your questions, but I can only say it's a wonder we don't suffer more from this disease. That describes our typical summer weather! There have been outbreaks here, but fortunately not frequently.

Sherry

[tjg911]

the question is will LB resurface again next year due to the extensive nature of LB this year.

thanks,

tom

[carolyn137]

Originally Posted by tjg911

the question is will LB resurface again next year due to the extensive nature of LB this year.

thanks,

tom

Tom, I think that question has not been fully answered as to spores. LAB has always been around but with the cold wet Spring conditions were perfect for more extensive spread and the bit about Bonnie plants being infected is still in contention since plants can be infectged AFTER they reach the big boc stores.

Information on the net is different for potatoes vs tomatoes and I'll try to find the time to transfer here some update info from Cornell on misinformation that's been spread around and also some links on where th LB has spread to within NYS and in the NE in general.

I'm just really pressed for time right now.

[dice]

The question is will LB resurface again next year due to the extensive nature of LB this year.

Maybe. Tania's outdoor plants in British Columbia seem to
get it every fall. Your winters are colder, though, on average
than lower BC west of the Cascades, so that may affect
its ability to overwinter.

[Blueaussi]

Cornell links

http://blogs.cornell.edu/hort/2009/0...oes-this-year/

http://www.hort.cornell.edu/departme.../lbmisinfo.pdf

http://plantclinic.cornell.edu/FactS...light/late.htm

[tjg911]

thanks blueaussie and carolyn.

i see in the links provided by blueaussie that the LB for tomatoes is not the same as for potatoes. i guess this is why the volunteer potato plants from missed potatoes from the 2008 season are not infected when the tomatoes growing next to them are.

i found 1 tomato plant sunday with LB, i removed it immediately. on monday and tuesday nothing. wednesday i skipped checking but today i found 6 new tomato plants infected. it appears i will lose all 11 plants at this rate. i decided to not remove the infected plants that show minor infection hoping some tomatoes will start to ripen and i can pick them, so many are just at the stage where they have started to get lighter green now. i have picked about 10 tomatoes and about a dozen cherry tomatoes, not exactly the summer i expected.

i am not sure what to do next year. i have always gardened organically never putting anything in the garden or on the plants that was not organic. if this means no tomatoes next year, and it's not going to be know until next year, then i may have to make a decision as to using fungicides, something I do not want to do. if i can't have tomatoes then there seems to be less of a purpose to have a garden, probably no purpose. i could buy all the various things i grow and save myself a lot of work. this is the most depressing gardening season ever, i never failed to have tomatoes thru august and september, i have never seen late blight.

tom

[Sherry_AK]

Tom -- I'm really sorry!

[dice]

You could try a hoop house next year:
http://westsidegardener.com/howto/hoophouse.html
(That materials list may not be exactly accurate.)

One does have to leave the ends open in sunny weather
so that they do not bake in there, so one might need
some kind of windbreak beyond each end to catch late
blight spores and other disease organisms carried on
the wind. One also has to irrigate, as rain won't reach
the roots. (I was wondering about some kind of pvc half-pipe
gutter beside the 2x4s, at ground level, with perforated pipes
leading off of it underneath the edges of the plastic into
the soil beside the plants, so that one would get at least
some irrigation from rainwater. Just an idea.)

My only issue with these structures is that the plastic cover does
not last very long, figure 3 years maximum, whether you use cheap
6-mil plastic from a hardware store or more expensive greenhouse
plastic.

[Robert Brenchley]

A hoop house appears to be what we call a polytunnel. A lot would depend on wind strength locally, but a neighbour of mine on a sheltered site leaves his covers for five years, and only replaces them then as he needs the maximum light intensity to grow show vegetables. I used to live on the Cornish moors, and a plastic cover there lasted about two years before it flogged itself to bits.

[carolyn137]

Originally Posted by carolyn137

Tom, I think that question has not been fully answered as to spores. LAB has always been around but with the cold wet Spring conditions were perfect for more extensive spread and the bit about Bonnie plants being infected is still in contention since plants can be infectged AFTER they reach the big boc stores.

Information on the net is different for potatoes vs tomatoes and I'll try to find the time to transfer here some update info from Cornell on misinformation that's been spread around and also some links on where th LB has spread to within NYS and in the NE in general.

I'm just really pressed for time right now.

Tom. I couldn't find this post when I went to post the links I promised you so started a new thread titled Late Blight Update in this Forum and I see that someone below has taken them from there and posted them in this thread as well.

I was trying to get most of the LB stuff in one thread, but I think it's a losing proposition right now.

So what I promised you is in that new thread.

[bcday]

Originally Posted by tjg911

i see in the links provided by blueaussie that the LB for tomatoes is not the same as for potatoes. i guess this is why the volunteer potato plants from missed potatoes from the 2008 season are not infected when the tomatoes growing next to them are.

I don't know if that's quite true, Tom. This strain of Late Blight may be affecting tomatoes more severely than potatoes, but that doesn't mean the potatoes can't get it too. Actually they are getting it, because I've seen it on potatoes here locally and I've heard a report or two of potato fields being mowed because the plants were too badly infected with Late Blight to have any hope of getting it under control.

It could be that your potatoes are a variety that have some tolerance to Late Blight so that it's taking longer to affect them. What kind are they?

Volunteer potato plants coming up from the previous season are one way that Late Blight is thought to be carried over from one season to the next. Check the Cornell Late Blight Factsheet again: http://plantclinic.cornell.edu/FactS...light/late.htm

If this year's crop of potato tubers become infected by Late Blight spores being washed down onto them through the soil, and those tubers don't get killed by freezing over the winter, any spores or fungal growth on them will also survive the winter. Then the volunteer potato plants that grow from those infected tubers next spring will spread the infection to all your other potatoes and your tomatoes next year.