Late blight already seems to be in some northern states.

[BlackThumb]

Allegedly there is confirmed cases in Boone and Kenton County Kentucky (part of greater Cincinnati) on the border of Ohio this year. Allegedly there are already confirmed cases in Kentucky, Pennsylvania, Maryland, Louisiana and Florida.


For next year I hope to have blight resistant tomatoes. Allegedly "Mountain Magic", and "Plum Regal" currently are the varieties that have the best late Blight resistance.

Late Blight resistance; allegedly
Ferline F1 Hybrid
Fantastico F1 Hybrid
Mountain Magic
Plum Regal
Legend

====
Could someone explain this to me in more simple and common language? It sounds like theoretically late blight could survive a freeze. It sounds like if it did that it might Metamorphoize into a more freeze resistant strain. It sounds like so far there is no hard evidence that it has survived a freeze yet.

The spores resulting from sexual reproduction are called oospores. Oospores are thick-walled dormant structures (Fig. 18) that can survive in the absence of living plant tissue. The occurrence of oospores could change the epidemiology of the disease because they can survive in soil over winter or summer (if soil temperatures do not exceed 40°C [= 102°F]). If oospores are produced, the soil may become a source of this pathogen, therefore adding an entirely new dimension to the epidemiology of P. infestans and the control of late blight. The result will be new "sources" of the pathogen. At the time of this writing (1998), there is no evidence that oospores are contributing to the epidemiology of late blight of potatoes or tomatoes in the United States. Nonetheless, the possibility of sexual reproduction exists and growers and scientists need to be alert to this development.

Source.
http://vegetablemdonline.ppath.corne...to_LateBlt.htm

Some of you Southerners (warm climate inhabitants) that are used to late blight and using fungicides; might not fully understand why some of us Northerners (cold climate inhabitants) being so ignorant and fearful of late blight, because for most of us back yard growers up north have never had to really worry about late blight because it hasn't affected the most of us. Usually the freeze kills it out and normally it doesn't have a chance to spread to the colder regions in time to decimate most crops. So I have been raising tomatoes for over four decades and never have lost a crop too late blight and have never used fungicides until last year. Though my tomatoes didn't catch late blight till well after the tomatoes peaked and were on the decline and it was near the time that I was starting to think about pulling the plants out of the ground because the temperatures were getting close to freezing. It was quite impressive how quick and aggressive the late blight was. In my over 40 years of growing tomatoes I have never seen tomatoes and the plants rot so fast. I guess I've never realized how privileged and/or lucky that I was that I've never experienced such a decimating disease or had to use fungicides.

Using fungicides is new to me; despite the fact that I've been growing tomatoes for over 40 years. Unfortunately now it seems like it might be necessary to use fungicides and to use extra precautions and preventatives.

[b54red]

Just wait til you get to experience TSWV; its' onset is so fast you won't believe it til you see it. Year before last most of the commercial growers around here had their crop wiped out and they spray every week at least but sprays don't help with that one or even with fusarium which can be avoided for the most part with resistant varieties.
That must be something to not have to spray for foliage diseases every week or so. I had one summer where the humidity stayed below 50% most of the season and had virtually no foliage diseases that year. The only drawback was the severe drought that forced us to spend a fortune watering our plants to keep them alive.

[TZ-OH6]

I figure somebody in this area has LB infected volunteer potatoes coming up right about now (could be me, but I pull them ASAP), and with all this rain I expect trouble soon, so I sprayed a couple of days ago.

[tjg911]

i agree, it's the lb infected potatoes left in the ground last year that worry me....

[kath]

Originally Posted by tjg911

... it's the lb infected potatoes left in the ground last year that worry me....

Me, too. I pulled about 8 in my own garden the minute I saw them among the peas, but once things really get growing, I wonder if I missed any. Thought I was really thorough in harvesting last year, too. And I wonder about all the people who might not even know they need to pull them and dispose of them properly.

[tjg911]

Originally Posted by kath

And I wonder about all the people who might not even know they need to pull them and dispose of them properly.

yeah those ARE the ones i really worry about! for the past 8-10 days it's been cool and raining except for 1 or 2 days. i am getting worried as the forecast for the next week is the same tho tomorrow and sunday may be in the 80's.

[carolyn137]

Formation of oospores can only occur in areas where there are two mating types of P. infestans, and that happens in the PNW, primarily, but not in the East where we have only the one mating type.

Potato cull piles certainly can be a source of LB b'c LB can overwinter in living tissue and those cull piles facilitate that, but LB doesn't overwinter otherwise since tomato vines are killed by frost in most places.

I'm sorry you're a bit late but if you look in the Seed Exchange, trade subforum, you'll see I made a free seed offer for NCSU varieties Mt Magic F1, Plum Regal F1 and Smarty F1, seeds from Dr. Gardner who bred them.

Smarty F1 is offered at Johnny's, but the other two were supposed to be made available commercially this year by Bejo seeds in the Netherlands, but it didn't happen.

I have very few seeds of Mt Magic and Plum Regal so don't know if I'll be offering them next year, or not. But by then let's hope they do become commercially available.

[Jeannine Anne]

Carolyn, you mentioned the PNW. I moved back here after 9 years in the UK. Before I left I gardened with no problems, I was on acreage with no immediate neighbours and was careful with debris, probably just luck but I never had blight growing on the open and never sprayed.

In the UK I gardened at home and also on a community garden where I was told the blight was really bad. We even got blight alerts when it was seen. I grew my tomatoes under glass there,but potatoes outside. Again I never saw blight, I always put it down to my toms being well protected although I did hear that other folks who grew in the open there did get it.

Now I am back and having to garden in a community garden . I have been told the blight is bad but I am not allowed to put up a greenhouse, I can put up a poly covering type of house but no glass. So far, as we have just recently got the ground, we have focused on getting on with raised beds for general gardening and have not had time to do the poly covering.

I am at a loss as to know what is best to do re the expected blight, should I spray, with what, the site is totally organic, will covering with a poly canopy be enough.. if I just let the plants grow naturally would I have much chance.

It seems I have to re learn everything I have done in the past and I am a bit overwhelmed by it.

You mentioned some blight resistant varieties, I wish i had known about these earlier..can I get them anywhere for next year do you know and does blight mean I will have to stop growing my collection of heirlooms that I adore.

Any help would be very much appreciated.

Thank you XX Jeannine

[carolyn137]

You mentioned some blight resistant varieties, I wish i had known about these earlier..can I get them anywhere for next year do you know and does blight mean I will have to stop growing my collection of heirlooms that I adore.

*****

Jeannine, you've referred to blight a lot but not to which kind of blight, which is a general word that many folks use to describe a sick plant.

Do you know for a fact that Late Blight ( P.infestans) is a problem where you're growing your tomatoes, or are you referring to Early Blight ( A. solani) which with Septoria Leaf Spot are two very common foliage infections along with Bacterial Speck and Bacterial Spot which are also two common foliage infections.

You asked above about the two varieties Mt Magic F1 and Plum Regal F1, which have the latest genes bred in for LB, but I already answered that in my post above and have cut and pasted it it here:

(I'm sorry you're a bit late but if you look in the Seed Exchange, trade subforum, you'll see I made a free seed offer for NCSU varieties Mt Magic F1, Plum Regal F1 and Smarty F1, seeds from Dr. Gardner who bred them.

Smarty F1 is offered at Johnny's, but the other two were supposed to be made available commercially this year by Bejo seeds in the Netherlands, but it didn't happen.

I have very few seeds of Mt Magic and Plum Regal so don't know if I'll be offering them next year, or not. But by then let's hope they do become commercially available.)

No, you don't have to give up growing your heirlooms. But you really need to know which diseases are said to be in yoour area as I mentioned above, b'c just using the word blight isn't enough.

[BlackThumb]

Originally Posted by Jeannine Anne

You mentioned some blight resistant varieties, I wish i had known about these earlier...can I get them anywhere for next year do you know and does blight mean I will have to stop growing my collection of heirlooms that I adore.

IMAO (not that I'm highly educated in agriculture)

Unless you are a tomato breeder or trying to maintain a impeachable heirloom I would recommend having some of each.

I would think having some late resistant hybred tomatoes might increase the odds that you have some yield if there is some late blight. However it is also important that as many as possible heirloom strains are preserved; because often they are the root of the breeds that give the hybrids immunity and/or diversity.

I think it is important to have a mix of crops to have some diversity, so if tragedy strikes hopefully at least some of the crop will survive. That is old-school; some of the new government welfare programs may interfere with that strategy because they only tend to subsidize major failure if you are a commercial farmer.

If you like heirlooms I would keep growing them. However it might be a good idea to have some disease-resistant crops as a backup.

I took a look this year for late blight resistant tomatoes in my area; to no avail. I hope things are better next year as I have sent several e-mails and have inquired in person asking that they have some late blight resistant tomatoes.

I had some seeds of heirlooms that are allegedly blight resistant but the ones I kept did not survive transplanting. I may have given some to a neighbor but I will only know for sure if they are and if it works if God forbids late blight strikes the neighborhood.

[Jeannine Anne]

Carolyn sorry it was late blight to which I was referring and sorry I did see what you said about the blight resistant ones, I got so wrapped up in my blight chat it went out of my head.

Thank you Xx Jeannine

[Jeannine Anne]

Thank you also Blackthumb, I agree with you and it is important.

I have been growing about 40ish years, not done much other than dehybridised a couple of varieties mostly because I never had the time to do the job well enough and thought it best left to others, but I have played around a bit in the background. Since retiring I thought may be able to follow that dream which I have had for years, but it could be lack of space which is getting in the way just now.

The late blight perhaps wouldn't worry me as much if I was still on my acreage, but with much less ground to grow in it makes things more difficult, realistically I need to use the little space I have with at least some degree of harvesting something.

I have grown a couple of "blight resistance" varieties along with other tomatoes , but more to see how they were generally. Ferline and Legend I think were the names... I disliked the flavour of both.

I guess I need to get more on the ball and see what resistant varieties are out there , never having needed them before I am way out of date I think. My collection of seeds is fairly good but never needed to look for these before.

I would like to know more about spraying in an organic way if possible, again an area I am very ignorant about.

Thank you again,

XX Jeannine

[carolyn137]

I had some seeds of heirlooms that are allegedly blight resistant but the ones I kept did not survive transplanting. I may have given some to a neighbor but I will only know for sure if they are and if it works if God forbids late blight strikes the neighborhood.

****

I don't know of any family heirloom tomato varieties that have any tolerance whatsoever to Late Blight, so if you end up growing some, please let all of us know about it.

Even Legend, which was bred by Dr. James Baggett at OSU was supposed to be LB tolerant but those I know in the PNW say no. it's not. But the NCSU varieties I mentioned above have a different and new gene for LB bred in and so should do much better.

Even conventianl hybrid varieties with bred in tolerance of the VFNT type are only tolerant, not resistant and give maybe a week or so more plant life, but that's important to commercial growers who decide when to harvest based on Brix values and that little bit of extra time can be important to them, but not that important to the home grower.

The most common tomato diseases are the foliage ones which are the most important worldwide.

[BlackThumb]

Originally Posted by carolyn137

I don't know of any family heirloom tomato varieties that have any tolerance whatsoever to Late Blight, so if you end up growing some, please let all of us know about it.

I'm not sure if it's classified as an heirloom or not; but it's not a hybrid or a cultivated strain; so by default I consider it an heirloom. It's actually allegedly a wild cherry tomato. I don't know if it's official or if it's just hype but allegedly Matt’s Wild Cherry tomato is supposedly late blight resistant.

Originally Posted by carolyn137

tolerant, not resistant

The way I heard it "tolerance" and "resistance" is the same thing. You seem to be using the words differently. You seem to be using the word resistance as if it gives the plant full immunity. The way I heard it tolerance and resistance merely reduces the odds that your plant will get the disease and if it does get the disease it will slow it down and give it more time. The way I was told it; "tolerance" and "resistance" does not guarantee "full immunity".

I don't know what jargon is right or wrong. It seems people use the language differently.

[Jeannine Anne]

I would define tolerance as something that would not hinder the plants development much, or in other words it would put up with it. Resitance I would define as the plant would be able to some extent be capable of holding it off. Immunity on the other hand I would define as something the plant would be completely immune from.

Therefore I would not expect to find a tomato that was immune to late blight,or even a tolerant one but possibly a resistant one.

This is the way I understand it, after reading seed catalogues.

XX Jeannine