OP or hybrids?

[travis]

Yeah, OPs have disease resistance. In fact, that's where a lot of the disease resistance in hybrids come from ... the OP breeding lines maintained to produce the hybrids.

Like Suze says, it costs plenty dough to test a variety for its disease resistance, and who's gonna pay the fee for such testing? Hybrids are created for their uniform and reliable production qualities, and that's where the profit is that pays the initial seed production and marketing costs.

As far as the varieties listed in the original post, most of those, except Sugar Lump, look like varieties sold in the 10c packets by American Seed Co. and its subsidiary, Plantation Seed Co. I've had great germination rates with all those seeds and had good success with the Rutgers and Super Marmande plants last year, neither of which succumbed to any diseases I can remember.

PV

[feldon30]

Originally Posted by peppereater

So if a named variety is followed by a string of numbers like "#38465" or something, it's still the same variety, but has been selected for disease resistance and other desireable qualities?

Tomato Growers Supply uses those numbers as catalog numbers I guess. Orange Russian #117 is one of the few exceptions. That's the actual variety name. Another is Homestead 24 F (F is for fusarium tolerance, this variety is sometimes mistakenly listed as 24F).

Originally Posted by peppereater

Is it then well past the F1 stage, and stabilized so as to produce seed of basically the same genetics?

Anything at heirloomseeds.com or seedsavers.org is OP and you can save seeds from it. TGS has a mixture and it's not always easy to tell. I had assumed that if disease tolerance was listed, then it was a hybrid but I guess some OP varieties are starting to be recognized for certain disease tolerances.

[feldon30]

Originally Posted by Mantis

Where are you getting all the info for your website Tim. You sure are getting a lot of varieties in there.
I look forward to adding my comments in about 6 months

Right now when I need to know about a variety, I check the "big 3".

TomatoGrowersSupply.com
SeedSavers.org
HeirloomTomatoPlants.com (Laurel's)

and if they come up short, DavesGarden.com. I know DG is the competition but they have such a good database. A real shame that more people don't post in it. It seems there are a half dozen plant databases and only 1-2 people vote in each one. If there was one big one, maybe it would encourage people to comment.

[lumierefrere]

Cornell University

http://vegvariety.cce.cornell.edu/

[elkwc36]

Lumierefrere. Thanks for the site by far the best I've seen and it's free unlike some. Great site and information. JD

[coronabarb]

"I know DG is the competition but they have such a good database. A real shame that more people don't post in it."

I actually joined DG right before Mischka started TV...I got tired of the GW carp. Waste of $, as I have never been back since joining this place. (no time for both sites)

[Lee]

Speaking of OPs that have disease tolerance,
Cherokee Purple has got to be near the top of the list
for Fusairum tolerance.
CP just laughs as the plants around it are falling prey to
Fusarium and it keeps plugging along.

However it can't take tomato spotted wilt virus.

Lee

[travis]

"I had assumed that if disease tolerance was listed, then it was a hybrid but I guess some OP varieties are starting to be recognized for certain disease tolerances." [Feldon]

Feldon,

What about all the OPs bred and selected over the years say from 1900 to 1950? Weren't those breeders lookin' for and selecting out disease tolerances from OP cultivar lines? So, I think that for a long, long time it has been a recognized fact that many, many old-timey OP cultivars have disease tolerances. 8)

Even after 1950, for that matter ... look here: http://www.wvu.edu/%7Eagexten/sustan...c/Moreon63.pdf for information on how West Virginia University developed multigenic type resistance to fusarium wilt in West Virginia '63, an OP cultivar bred and selected from a series of OP cultivars with varying degrees of resistance. :wink:

In fact, it's my impression (which of course may be a mistaken impression) that the original move toward hybrid cultivars was not necessarily due to disease resistance, rather for the uniformity and hybrid vigor afforded by hybrid cultivars.

Yeah, there's a lot of disease tolerance bred into modern cultivars, and that's a good thing, but I really think it's a mistaken impression that ONLY hybrids have disease tolerance. Again, one should consider that those tolerances originally come from OP breeding lines. :wink:

PV

[feldon30]

So then the question is, why are V, F, N, etc. listings rare on OP tomato listings? Is there some law that says you can't show those tolerances unless it's recently certified?

[TheDens]

Just a guess, but I'd think the companies that produce the hybrids are more likely to pay to have them tested. Disease tolerance is a big selling point, and the more letters there are following the variety name, the more likely they are to make their money back. Companies have less financial stake in OP's, so aren't going to spend the money on trials.

Denna

[travis]

"So then the question is, why are V, F, N, etc. listings rare on OP tomato listings? Is there some law that says you can't show those tolerances unless it's recently certified?" [Feldon]

I don't know if "there's a law..." but wouldn't you think there's ethics involved?

Again, some sort of testing would be involved to determine disease resistance or tolerance, and someone would have to conduct the tests and someone would have to pay for the tests. And, yes, I would think that such tests would have to be conducted on some sort of regular schedule to ensure that the resistance or tolerance is maintained since you're dealing with homozygeous, open pollinated lines.

What about maintaining pure bred lines, Feldon? Certain breeding programs maintain pure bred and inbred lines generation after generation for the sole purpose of maintaining disease resistance in the open polinated or back crossed breeding lines used to create hybrid cultivars.

In those programs, the disease resistance or tolerance is maintained by the breeders and can be certified. Some of those programs, particularly at land grant universities, maintain dozens of pure lines of disease resistant and tolerant open polinated cultivars.

If a seed vending company would like to maintain, or cause to be maintained, a pure line of say Creole or Cherokee Purple tomato, then they can do so and have it tested for whatever tolerance it may consistently exhibit.

But I think that's not exactly what happens regarding the plethora of open pollinated seeds sold by the majority of companies vending "heirloom" seeds ... do you?

So, anyway, I have a couple of emailed requests in asking folks who should know about what standards or possible laws may govern certification of disease resistance, etc., and I'll forward that info to you when and if I get it.

PV

[feldon30]

I'm completely new to tomato growing, so I don't know what the various resistances mean for the home gardener.

I would imagine in a farming situation, different plots of land might have different diseases in the soil and so you plant certain tomatoes in certain places.

But in the home garden, it's not life or death (some might argue ) and once you identify a problem disease, you have to pick different varieties.

In a perfect world, every seed saver would bag their blossoms and meticulously track and segregate seeds and always identify the source tree.

So the question is what harm would an unofficial list of varieties and known tolerances do? I know you get into the apocryphal situation plus misidentification of diseases is a problem, but peer review would help with this.

[travis]

"So the question is what harm would an unofficial list of varieties and known tolerances do?" [Feldon]

Well, as I was tryin' to indicate ...

How can you be sure that Cherokee Purple from Seed Vendor "A" is the same as Cherokee Purple from Seed Vendor "B" and has the same degree of tolerance to the same disease? What are the individual sources of the seeds from each vendor? Who maintained the individual inbred lines? Who tested each line for its individual tolerance or degree of tolerance? Can you be as sure as you are when you order Mountain Spring, for example? http://www.ces.ncsu.edu/fletcher/pro...llenlines.html

Who's gonna maintain this "unofficial list?" Who compiles it in the first place? Upon which inbred lines of each variety is the attested tolerance bestowed and by whom? In other words, who officially makes the determination that a variety qualifies for the "unofficial list?"

I would think that unless a qualified labratory or agricultural field station determines resistance or tolerance by an accepted testing method, and subsequently that same line of cultivar were maintained and periodically retested, that a seed company would be less than ethical to advertise a particular open pollinated variety as resistent or tolerant to a specific disorder. And remember, things can change when you're dealin' with open pollinated, inbreeding populations ... remember evolution

However, if you wish to compile a short list of tomato varieties that reportedly exhibit tolerance to heat, nematodes and foliage disorders, the information is there for you to do so. Have at it. :wink:

PV