[QUOTE=Ricky Shaw;526401]0-33, You think the breeder was implying a tolerance to wide temperature range? In Fahrenheit those numbers are 32-91.[/QUOTE]

I think that 0.5 ° C ...... 32.9 ° F
Vladimír

This is an English translation of the text from the Russian Internet, which MAF said here on Tomatoville:
[url]http://www.tomatoville.com/showthread.php?t=25599&highlight=Stepniak&page=2[/url]
Sarajevo tomatoes: a remarkable legacy
Spring frosts in many areas there are up to June, and often early planted tomato seedlings die. Help avoid this kind of Orenburg breeder Paul Sarajevo, which for decades led the work on breeding tomatoes for resistance to cold.
The main thing - the wind and moisture
Cold-resistant varieties can be planted seedlings much earlier than usual and, respectively, before a crop. And the use of film shelters accelerates ripening and significantly increases productivity. However, speaking of Sarajevo resistance varieties to frost, you should know that this is only possible at low humidity (dry air) and windless weather.
For a long time scientists advised growers evening and night watering as effective against frost. Similar recommendations are found in the literature and now, but this is false. Everyone knows that a man in wet clothes is much colder, especially in windy conditions.
Evaporation causes cooling fluid, and along with it - the cooling of the body. Hypothermia can be even at zero temperature, if increased humidity. Wet surface gives four times more heat than dry.
Gardeners necessarily consider when early spring transplanting two main factors: humidity and wind.
After planting, water the seedlings need a time, and not to do this until there is no danger of frost.
In the period after transplanting until it settle down, the plants decreased resistance to cold, so the seedlings should be planted with minimal damage to the root system (eg pots) that the period of survival was minimal. When growing seedlings should be periodically from the moment of its emergence exposure nighttime freezing temperatures, ranging from a few minutes hardening and increasing it to a few hours. When planting in the ground need to protect seedlings from wind any available material.
Most hardy varieties
Spiridonovskaya. Undersized, standard, precocious. The fruits are small, up to 60 g, red, suitable for canning. From germination to early maturation under favorable conditions, is 80-90 days. Resistance to low temperatures was confirmed by the Institute of Biology, Karelian Branch of the RAS. When tested in young seedlings survived four frozen to -14 °.
Orenburzhets. Undersized, standard. Red fruits, weighing 80-100 g, good taste, universal purpose. Endured three consecutive freeze: -5 °, -7 °, -10 °.
Kemerovets. Undersized. Pink fruits weighing up to 100 g, high commodity and taste, universal purpose. Withstood freezing -7 °, -10 °, -13 °.
0-33. Srednerosloe. The fruits are large, up to 200 g, flat-round, red. Beginning maturity - Mid-July, the yield per bush - more than 6 kg. When tested survived two freezing and one -9 ° -7 °.
Stepniak 50. Srednerosloe. Red fruits, weighing 30-50 g, rounded, smooth, multi-purpose. Is resistant to temperature variations. Went through five freezing to -10 °.
I-3. Average height, very early, in good years the fruits ripen in late June. High-yielding. Fruits are flat-round, red, weighing 100-200 g when tested went through five frost from -6 ° to -11
Siberian. Srednerosloe. Fruits are flat-round, red, large, fleshy, high taste. Variety is very crop. When tested withstood seven frozen to -10 °.
Lemon. Tall, late-maturing. The fruit shape and color to its name, weighing 70-80 g, hang huge brushes, very harvest. The fruits are fleshy, well-kept, suitable for canning. Through three freeze to -10 °.
M-16. Tall, late-maturing. Fruits are very beautiful shape, good presentation. Weighing 200-300 g, fleshy, good taste, well kept. Tests: one frost -3 °, two - on -10 °.
Tomato F1RR. Fruits bright red, flat-round, multi-chamber. The pulp is fleshy and juicy, with a high sugar content, has amazing taste. With proper care and rationing of the ovaries in the brush can grow fruits record up to 2 kg! The plant is vigorous, indeterminate. Fruits ripen 130-140 days. Juice of them get a very thick, well and quickly boil down to the consistency of a paste, and one fruit salad can be prepared for the whole family.
MA Litvinov, p. Novoaleksandrovka Orenburg region.
Vladimír

Thanks,Vladimir.
How about the soil temperature ?

Gardeneed

I've tried to locate a paper/study from the mentioned institute but no luck sofar

Vladimir thank you for posting the translation.

My Taimyr is up after 6 nights, 3 for 3 on seed germination. Only got 6 seeds in the MMMM swap, so this pleases me.

No movement on the 0-33 yet, 4 seeds planted. Taking kind of long in my short experience. Most tom seeds are up for me after 4 full days and nights. I don't soak or treat, maybe I should.

[QUOTE=Ricky Shaw;527519]My Taimyr is up after 6 nights, 3 for 3 on seed germination. Only got 6 seeds in the MMMM swap, so this pleases me.

No movement on the 0-33 yet, 4 seeds planted. Taking kind of long in my short experience. Most tom seeds are up for me after 4 full days and nights. I don't soak or treat, maybe I should.[/QUOTE]

even w soaking, some can take as long as 10 days.

On Wednesday I send:
20 seeds 0-33 (control)
Seeds 20 seeds otužených
12 seeds (prepared as follows: 48 hours soaking and after drying 48 hours freezing at 6 ° C)
Two seeds - Saraev M-22, I-Saraev 1 Saraev Otbor 1 Saraev Gruntovyi, Saraev Shtambovyi, Saraev Stoikyi, Saraev Druzhnya, Jagodka, Kalinka, Latah, Darinka F1, Iceberg, Jantarnoi.
A total of 80 seeds. Saturday had all the seeds sprouts (100%). I peppered seed with substrate and I put crucibles on a window in a room with 18 ° C. There will be grown by the end of March.
Vladimír

That is amazing... really tough tomato seeds, if they can withstand soaking,drying and then freezing, and then germinate 100%. These are really harsh treatments, like you would expect outdoors if planting "too early"... awesome results. 8-)

Excellent results Vladimir! Seven days and still no movement on my four seeds of 0-33. I've sown six more this morning, it's the last, but I've sent to Tatiana for more. I'm not ready to give up on 0-33 and will be staying tuned in here. The Taimyr is doing well.

I have to prepare the seedbed in March so that the ground temperature was 10-12 ° C. I want to use the experience of Tania mentioned in the thread
[url]http://www.tomatoville.com/showthread.php?t=33331[/url]
I want plant 0-33 seedlings during April 0-33. I will begin only when will be forecast for the next two days more than 15 ° C. Subsequent to four days I'll plant the next seedlings.
Vladimír
PS.: It looks like the weather in my garden in April. What will be the April 2016?

I have to prepare the seedbed in March so that the ground temperature was 10-12 ° C. I want to use the experience of Tania mentioned in the thread
[url]http://www.tomatoville.com/showthread.php?t=33331[/url]
I want plant 0-33 seedlings during April 0-33. I will begin only when will be forecast for the next two days more than 15 ° C. Subsequent to four days I'll plant the next seedlings.
Vladimír
PS.: It looks like the weather in my garden in April. What will be the April 2016?

Vladimir, I really like how you used colour in the graphs. Your April variation looks a lot like my April in the greenhouse. A lot of variation from year to year... hard decisions.
I am finding it makes a big difference even to get several warm days at planting time followed by cold. It wasn't good to plant them on a cold day or just before several days of cold.

I also plant out in April. Prior to that I cover the beds with black plastic, to warm up the soil.
I plant out when soil temperature is 50F+to 57 (=10C- 14C). Our early April air temperature is in 40F-60F range ( = 4.5C to 15.5C). So there is no frost but it will take a long time for the weather to warm up like the middle of May. That is when traditionally people around here plant out tomatoes.
Gardeneer

Bower,
I did not make the graphs. These are graphs from the weather station CHI, which is 2 km from my garden. Performs measurements since 1939 and graphs are on the internet.
On the chart also indicated average values for 75 years of measurements (max and min).
I will use their graphs for the evaluation hardiness of tomatoes in this season (I do not have to perform any temperature measurement)
Vladimír