Topic: Blight resistant tomato varieties

[Jayb]

Hi Jayb

I splashed out on the Crimson Crushes too as soon as I saw them.

I was thinking of trying to cross them with my best and tastiest outdoor croppers if I'm around at the right time (Stupice and Aurora).  I think it's worth a try and easy to see if it works.

But, I was reading the Savari Research Trust's website a while back and (from memory) they say in the mid-seventies a variety of blight which mutates was imported into Europe in potato tubers which is why it has become such a killer for outdoor tomatoes so for how long this variety will be blight-free it seems to me is debatable.

Anyway, nothing to lose!  Yes, let's compare notes and breed away....

Earlypea

Great, a co Crimson Crusher grower 
The crosses you have in mind sound good, tasty outdoor types, got to be the way to go. Though I'm not sure on the grow out numbers to capture both PH2 and PH3, guess just keep whatever survives the season well.

Yes from what I understand LB strains are able to change and mutate and have become more aggresive. Previously resistant potato and tomato varieties have succumbed to the new strains. Crimson Crush along with a few other varieties have 2 types of resistance which gives added resistance but likely to show some signs in a prolonged attack, hopefully they should be able to grow through it.

I might try a Crimson Crush cross to Mountain Magic and or Defiant, though both are F1 varieties.

[Jayb]

I grow Green Tiger (from M&S - aka. "Highlander" from seedsmen) for its unusual meaty flavour - also the round shape seems less blight prone than beefsteak types.

I didn't realize green tiger was same as highlander.. ...but yes, it has unusual flavour and I like too..though sometimes the skin is quite tough one on them. 

That firm flesh and thick skins seems to be a common trait to several very similar black/green striped cherry varieties. I wonder how similar the breeding stocks, perhaps they all originate from the same? Green Tiger and Highlander are indeed very similar though Highlander were sold as an F1 variety. I'm planning on growing Safari this year which is an open pollinate variety from Red Star Safari, originally from the Netherlands, although Safari looks to be a round cherry selection rather than elongated plum cherry type.  I think it will be quite similar to (British) Green Tiger. 

[kGarden]

You guys worry me - you are going to have to actively encourage Blight onto your plot to see if your crosses are working  !!

[Jayb]

You guys worry me - you are going to have to actively encourage Blight onto your plot to see if your crosses are working  !!

Not sure I follow you or the angry face?
LB needs no hand from me and arrives here each year, presumably carried in the air when conditions are condusive to it's development. I admit I don't activly try and prevent blight as I no longer use toxic chemicals to prevent it and don't want to so. Buying a naturally bred variety that is reported to be blight resistant and grows well out doors seems the way forward. Plus for me, being able to use excisting LB resistant varieties to make some new varieties that will suit my garden, growing conditions and my taste, seems fine to me.

[kGarden]

Seems like playing with fire to me :)

I wish you luck, not sure how you control the testing of whether what you are breeding is blight-resistant, without putting your harvest at risk - and your neighbours too ....

If you cannot avoid blight at all, year on year, then I guess you are in a good geographic location to try the breeding. I suppose if you save-seed early in the season, before Blight, you can the re-bred from those for F2 / F3 generations that might improve on the F1s ...

Do you get away without blight in greenhouses at all? I know greenhouse crops are susceptible, but thought they were somewhat less likely to be infected - no rained-on foliage, and with door closed / not facing prevailing wind then some chance that the spores don't naturally enter.

[Jayb]

I really can't see how it is playing with fire any more than me growing any other variety of potato or tomato outside. Perhaps it is less as they may be LB resistant. Both potatoes and Toms are at risk each year and harvest is normally dependent on when Late Blight arrives, some years this can be as early as the first half of June.

If I were looking to save seeds from a LB resistant variety, either a commercially available variety or a 'homebred' one, then it would be selected because it wasn't affected by Late Blight. So in this case best not to rush to save seeds early in the season before LB strikes. Growing these really would put no more risk on my crops or anyone else.

I do grow quite a few tomatoes in a greenhouse and poly-tunnel too. It would be the norm for outside crops to be affected, where with luck and care, greenhouse and poly-tunnel crops are unaffected. Though one year I discovered it in the poly-tunnel first and with the weather combinations (lots of fog, drizzle and mist) at the time it had spread very quickly.
Also my experience here is the LB strains usually affect the potato crop first, with affected leaves showing about 10 to 14 days before tomatoes. Potatoes are affected very rapidly and it spreads unbelievably quickly and needs to be dealt with straight away. Tomatoes are somewhat more resistant in that if any leaf is noted early with blight and removed then the remainder of the plant has a good chance to remain healthy. If not noticed at the first sign then it is usually best to cull the plant. One year tomatoes were affected while the potatoes remained untouched till much later in the season. What a treat it would be not to have it at all!

[kGarden]

So in this case best not to rush to save seeds early in the season before LB strikes. Growing these really would put no more risk on my crops or anyone else.

My thinking was that your F1 might not be blight resistant, but your F2 might be - hence I'm thinking better to save seed early, before blight, in case gene is carried recessive in F1 and then double-recessive in F2

I do grow quite a few tomatoes in a greenhouse and poly-tunnel too. It would be the norm for outside crops to be affected, where with luck and care, greenhouse and poly-tunnel crops are unaffected

I was hoping that would be the case.  Some comfort at least. I too have had friends who have lost greenhouse crop unexpectedly in a few seasons.  Possibly a different strain that year, or just a wet & humid, dismal summer as you described.

[galina]

Do you get away without blight in greenhouses at all? I know greenhouse crops are susceptible, but thought they were somewhat less likely to be infected - no rained-on foliage, and with door closed / not facing prevailing wind then some chance that the spores don't naturally enter.

kGarden, there are blight spores ( blown in by the wind and absolutely everywhere) - nobody can help those.  Then there are the virulent, activated blight spores - and it is the latter that do the harm.  Activation happens after a certain amount of humidity.

Wiki explains it much better than me:
http://en.wikipedia.org/wiki/Phytophthora_infestans

If greenhouse doors stay closed, humidity goes up inside - bad idea!  They need to be open and the vents too, in order to get air flow happening which dries off damp and reduces humidity.  It is easier to ventilate a greenhouse than a polytunnel, which is why there is more blight in tunnels.  It is important to leave doors open - nothing will stop the blight spores, they are blown in on any breeze or come in with the gardener, but you can largely stop the activation of late blight spores by preventing tomato leaves staying wet for hours. 

Obviously watering directly onto foliage is also a very bad idea for the same reason that tomatoes out in the open, which get rained on, are at risk. 

[gray1720]

Are they Ferline F1?

Yes, they are.

Adrian

[kGarden]

there are blight spores ( blown in by the wind and absolutely everywhere) - nobody can help those.  Then there are the virulent, activated blight spores - and it is the latter that do the harm.  Activation happens after a certain amount of humidity.

Thanks, I'm familiar with the mechanics of Blight.  Blight is rare where I am - I don't know if that is because it is drier here (in East Anglia), or because I have no near neighbours growing Spuds or Tomatoes.  Certainly the agricultural land near me is just Wheat / Barley / Rape and, for as the crow can fly without a rest!, into the prevailing wind there is only agricultural land.  The Blight Watch Email thingie sends me less than 10 alerts a season, and nearly all of them are the warning type (Smiths Period I think, maybe there is even a less severe alert than that ...) rather than an actual outbreak in the vicinity.  Clearly I am in a very lucky position, compared to growers elsewhere in the UK, but hence I am also only vaguely aware of the relative infection of Potatoes / Tomatoes outside/inside glasshouse from what gardening chums have told me. I'm always keen to learn though, and better understand such things - if only to be able to relay knowledge to others.

I have a reactively large glasshouse. I don't need to open the door to get ventilation, except on very hot days.  My door is, by design, not facing the prevailing wind - so for blight spores to get into my greenhouse it has to be very hot, for the door to be open, and come from a non-prevailing wind direction, or the spores have to get in through the vents.  Of course they can swirl about and get in anyway ... but "In principle" I'm well placed to avoid it.  I also don't water the foliage in the greenhouse at all (leaky hose irrigation onto soil, under weed suppressing membrane, so water being sploshed about.

Interesting as to why Blight outbreak in Polytunnel is worse than Glasshouse - makes sense now you say it, thanks.

[Robert_Brenchley]

Theres an easy way to test for blight resistance. Grow whatever it is on a site like my allotment where theres an outbreak at some point every year, and see whether it succumbs. It works with my potatoes, so it should work with toms.

[Paulh]

Question - is it the same strain okf blight that affects potatoes and tomatoes? This seems to be assumed above in the discussion; I thought they were different.

[Robert_Brenchley]

Yes, if one gets it, the other very soon follows.

[Vinlander]

Well, I grew GT next to Highlander and the taste was the same, the unusual stem-blackening response to burgundy mix spray was the same, and many of the fruits looked identical (though there is quite a wide range of shapes, dimples/beaks etc. in GT).

I didn't have enough Highlander plants to say if they were less variable - as you might expect a seedsman's selection to be.

The last M&S packet I saw only suggested you cook them - yes I'm sure they are great for this but it's missing 90% of the point for me!

If a fruit doesn't taste good out of hand I don't grow it. I know people grow tomatoes to use as vegetables but if I find any tomato that tastes like a vegetable I grow something different next year...

For me, pears are about the only fruit that tastes as good but different when cooked (lightly & properly). I do buy canned lychees and I also like peach schnapps but only because it doesn't taste like canned peaches.

I do cook bananas too - but only when I can't be bothered to wait the 2 or 3 weeks before they ripen properly...

Cheers.

[amphibian]

I'm also growing Crimson Crush for breeding futures.

Ph2 and Ph3 are co-dominant. The problem is we have no idea whether the plat is really an F1 or not and if it is whether it is homo or heterozygous at these loci.

Simple selection by which plant survive the blight will not necessarily preserve both genes as some resistance is connoted to each gene separately.

[Jayb]

Good to have another Crimson Crush grower, it will be interesting to hear how they do in the different locations. Suttons have said Crimson Crush is not an F1 variety, so should if they are correct, CC will be true from seed and give stable F1's from crossing.
Simple selection may not be fool proof but will help narrow the field.

[Jayb]

Crimson Crush plugs arrived this morning. They look to be rooted cuttings rather than seedlings and still quite small with not much root as yet. I've potted them up and popped them in the propagator, which will hopefully give them a little boost.

[amphibian]

Crimson Crush does not have f1 in its name but according to the symbol at top right Suttons are claiming it is an F1 in some places.

[johhnyco15]

i got some free seeds from t&m  dont know the variety watch this space for cropping and plant health

[Jayb]

Crimson Crush does not have f1 in its name but according to the symbol at top right Suttons are claiming it is an F1 in some places.

That's confusing, when I emailed them they wrote back to say they were not an F1 variety.