Author Topic: Heat tolerant, Heat Resistant, Hot Climate Tomato Varieties and breeding  (Read 123 times)

William S.

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I am interested in climate change breeding and given last summer's heat wave which caused a great many of my tomatoes to pause setting fruit or to apparently set seed free fruit for a long time I thought I would look into maybe looking into heat tolerance.

Towards that I recently purchased a packet of Flamenco tomato a tomato descended from Silvery Fir Tree x Floridade from Lee Goodwin's J & L Gardens websites heat resistant section for growing in 2022.

I just did a search for others looked at several lists and here is what I found already in my collection.

Brandywine- just bought a packet because of Craig LeHoullier's top ten flavor list
Celebrity- have some segregating descendents not the actual hybrid.
Green Zebra
San Marzano- have some old seed
Stupice- old local standard here
Yellow Pear- haven't grown out in awhile!
Isis Candy- may be getting soon in a seed trade
Blue Ambrosia- the variety I got from Lee Goodwin's J & L gardens that is the source of many of the segregating lines in my collection including Exserted Tiger because of exserted stigmas.
Fourth of July Hybrid- wonder if this works more as a heat avoider ripening before it gets too hot? If so all the ultra early types would work for that.
Lucid Gem - Brad touts its heat tolerance on the wild boar farms seed page about it.

Wonder if I made any notes on here somewhere as to what did well last summer during that. 
« Last Edit: 2022-01-09, 03:55:32 PM by William S. »
Western Montana garden, glacial lake Missoula sediment lacustrian parent material and shallow 7" silty clay loam mollisoil topsoil sometimes with added sand in places. Zone 6A with 100 to 130 frost free days

Diane Whitehead

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Are there any tomatoes from desert areas that can withstand both cold and heat?

I remember staying in one desert area in South Africa during spring.  The temperature was minus 8 celsius at night and plus 22 the next day.   I didn't check anyone's vegetable garden, though.
Victoria, British Columbia, Canada
cool mediterranean climate  warm dry summers, mild wet winters,  70 cm rain,   sandy soil

William S.

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I've wondered that as well. I feel like the ideal tomato here would be short season, cold tolerant, heat tolerant, and more! Can we have everything we want in the same tomato? That is part of why I chose the Flamenco I thought its Silvery Fir Tree parent might give it a chance here. When I was working in Boulder City Nevada the winter of 2012-2013 the back yard of my rental was bare soil, so we planted a garden and at the local garden center the tomato varieties were very different than any I had heard of. My neighbors there said that there is a very narrow window in the Las Vegas area for tomatoes and mine probably wouldn't produce. Then we took a job monitoring rangeland vegetation and left before we could find out for sure. 

I think it makes sense to cross very different or opposite tomatoes even though it is possible the results especially in early generations could be unremarkable.
« Last Edit: 2022-01-06, 11:24:27 AM by William S. »
Western Montana garden, glacial lake Missoula sediment lacustrian parent material and shallow 7" silty clay loam mollisoil topsoil sometimes with added sand in places. Zone 6A with 100 to 130 frost free days

Steph S

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I  can vouch for Stupice and its descendants as being more heat tolerant than average.  Not surprised to see San Marzano listed either, and there are probably others selected for Italian growing conditions that tolerate heat and drought better than average.
Growing in a greenhouse, you are constantly trying to moderate extremes.  We get huge temperature swings and lots of experience with tomato stress from heat as well as cold.  There is UV stress too, if you have a week of overcast weather, the sun blazing out for a day can cause them some serious distress, even if the heat is vented.  If you get into a string of sunny days, they adapt to it, but the abrupt changes are challenging. 
One interesting fact is that night temperatures are important for fruit set.  If the nights are over 70F, they don't set, or set poorly.
Another rule of thumb is that tomato pollen is sterilized at temperatures over 95F.  So unless your flowers are getting some cooling - shade, breezes, etc - they don't have much hope of setting fruit in those conditions. 
Plant architecture is an important consideration, whether they will set well in spite of the heat.  I often look very closely at how the plants are structured, whether they put out a shade sucker early enough to protect the flowers, and whether the distance and orientation of the suckers vs the clusters is helpful or not. The same features also allow them to shelter flowers and fruit from cold.
Another interesting feature is the ability to set fruit even without pollination - adaptive or facultative parthenocarpy in plants that are normally seeded.  When pollen fails under heat stress, some plants will produce a reduced, seedless fruit instead.  And that's okay, when you need something to eat it is better than getting none at all.  I also like it that the plants are investing in animal attention, even if they won't get seeds.  So you keep watering them, and when it cools down they go right back to producing normal fruit again.





William S.

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That seed free fruit last year was weird!
Western Montana garden, glacial lake Missoula sediment lacustrian parent material and shallow 7" silty clay loam mollisoil topsoil sometimes with added sand in places. Zone 6A with 100 to 130 frost free days

Jeremy Weiss

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I see a lot of talk here about heat/drought resistant tomatoes.  However I think it may also be useful, given that there ARE El Nino years, to talk about tomatoes that can handle both excessive heat and EXCESSIVE water i.e. ones that will do well if it rains constantly.

To that end, I think mention should be made of the tomato Nagaraclang (I think that was how it was spelled). This was a tomato I heard about about a decade ago (thought never successfully grew myself). Apparently, it was a black fruited tomato that hailed from the Philippine jungles and was notable for the fact that it's flowers would actually shed water in heavy rain (as opposed to most tomatoes, where heavy rain will destroy the flowers). That always sounded to me like a useful trait to have. 

Nicollas

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That Nagaraclang Nagcarlang seems interesting.

Available at ARS GRIN :

PI 273445 / Nagcarlang
"Plant erect, stiff, to 49 inches high and 11 inches wide; fruit 1.6 by 2.5 inches, distorted shapes, purple, seven loculed, late maturing. A wild, cold-resistant type with protruding pistils which set fruit under rainy conditions. "
« Last Edit: 2022-01-06, 11:35:01 PM by Nicollas »

Steph S

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There are some other interesting cases of adaptation to extremes in the Philippines.  I recall reading about Calamondin, a citrus fruit that ostensibly evolved to tolerate the darkness conditions associated with volcanic eruptions.

William S.

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https://doublehelixfarms.com/nagcarlang

So there is a commercial source also found a TGRS accession number so it is well represented in the gene banks.
« Last Edit: 2022-01-07, 07:50:06 AM by William S. »
Western Montana garden, glacial lake Missoula sediment lacustrian parent material and shallow 7" silty clay loam mollisoil topsoil sometimes with added sand in places. Zone 6A with 100 to 130 frost free days

Jeremy Weiss

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https://doublehelixfarms.com/nagcarlang

So there is a commercial source also found a TGRS accession number so it is well represented in the gene banks.

Hmm, maybe THAT'S why it makes such a good and common houseplant (if you have ever seen those trees with the marble sized "oranges", THAT'S a calamondin)