Early black F5's in 2019

[bower]

I couldn't make the commitment to a big grow this year, but a couple of friends stepped up so some lines I couldn't push forward are being grown by them. N. is growing the Black Kitten Paws F5, and very stoked about the huge clusters of fruit, also says they are keeping pace with Sungold and look to ripen first fruit about the same time. S. is growing the indeterminate purple Skipper F5 that was earliest last year and the best fruit quality all season long. This line is the one she selected two years ago at the farm. I'll get a look at those in a few days on the plan to help prune and tie. And I'm growing some Rodney F5, and two determinate Skipper lines here, a brown and a purple.





The determinate Skipper lines were the result of a cross between siblings in the F3 generation, and I'm seeing more segregation than there is in the Rodney or other true- selfing F5's. Skipper Brown for example, has some obvious segregation for growth habit, with one plant much taller than the others. These were planted out in early July, around the time I would usually have first ripe fruit. The difference in growth habit is obvious from early on (first pic).



This got me thinking about growth habit, and how it affects the success of the plant in hot weather instead of cold.

[bower]

I normally plant very early to get as much fruit set as possible before the 'greenhouse effect' kicks in with midsummer sunshine and high temperatures that would cause any tomato to drop blossoms. One reason that I like determinates is because the high temperatures when plants get up close to the glass are a killer for most. When they get too tall, it's over. There are a few notable varieties that I've seen set fruit even close to the glass in blazing sun, but chances are in general better for a shorter plant in my greenhouse. So the big question on my mind this season, how will these varieties selected mainly for their growth in the cold, also manage instead setting fruit at the hottest time of year.


Pretty well all of the plants dropped a few blossoms in that first cluster, when they were dealing with transplant stress and heat stress at the same time, and had not filled out. Here is a nice double cluster on Rodney positioned between two stems. Rodney has done well in previous generations, to continue setting through the hottest time of year.

[bower]

Did you ever notice, how tomato plants will cup their leaves over a flower cluster to give it some shade? (They do this to protect them from cold too.) I've often noticed how tomato plants especially beefs, use their suckers to try and support their fruit. But there's another reason for suckers... protect those flowers.

[bower]

My thought is that tomato architecture plays a role in the ability to succeed and bear fruit when temperatures are pushing the upper limits. Plants with dense suckering, with suckers that come up fast enough to top the cluster, and short enough internode spacing for that to be effective, should have the best chance to protect the flowers and set full clusters in the heat.

[bower]

That tall skipper has the worst chance of losing blossoms due to sun exposure. The internodes are too long for the next leaf up to provide optimal shelter, and with all that energy into vertical growth, not suckering as fast or densely either.

[bower]

I had fun looking for all the shelter around fruit. Tomatoes are such motherly creatures, no surprise to see neighboring plants reaching out a leaf to add shelter for the little ones next door.

[Whwoz]

Some interesting results so far Bower, love the work being done in Canada lately

[bower]

Yeah Whwoz, I'm really looking forward to try KarenO's bicolor hearts too.

We are into a run of miserable summers here, with Greenland's meltwater and bergs close at hand. When the cold weather breaks it's unusually hot - and the glasshouse in July and August is anyway out of the goldilocks and into 95F+ on sunny days. So between the extremes suffered, and how little time I devoted, I'm really pleased with how low maintenance this year's group have been. These lines have been outstanding for foliage health in all generations, with a few exceptions that were culled along the way.

Other than one frantic afternoon of tying up, I have done nothing this summer except water and open the greenhouse in the morning. Occasionally take a minute to brush off the blossom ends. Not one blighty leaf have I found to remove the entire season. I have a pest in the greenhouse that has mined some leaves and I've picked a few of those off, is all. Zero pruning on determinates, until I topped them all a few days ago to try and ripen up what's there.

So I feel I've made some progress towards the low maintenance short season tomatoes that I wanted.
The indeterminate Skipper at the farm greenhouse also made a healthy row with lots of fruit, very consistent at F5 and identical to last year's early delicious tomato with a reduced point but almost sharp as a thorn. The two pink determinate Skippers that I grew were not identical - one larger fruited but without the classy pointy shape. Both are good eating but I prefer the earliest, pointy shaped one with the tight clusters. Sweet and rich with a grassy peel. Those sibling crossed determinate Skippers may take an extra season to stabilize. Still it is exciting to be saving F6 seeds.

[bower]

Rodney F5 - it was interesting to see the different responses to the heat in this generation. One plant - Rodney #3 - was more compact than the others, and did not drop many blossoms at all. Count of fruit at topping time was 51, compared with #2 at 45 fruit and #1 only 28. The larger first fruit on #1 was set alone with the rest of the cluster dropped. Fruit size from plant to plant is varied and not consistent, except that overall the fruit this year are noticeably smaller than normal.
You can see when cut, the smaller fruit are very dense and they are missing a locule or two. So this is one type of response to heat which I have seen in other plants - parthenocarpic or few-seeded fruit often with reduced size, firm flesh, in weather that's too hot for normal setting.

They are sweet and good however - except for that larger #1 fruit was not sweet at all and still waiting on a second ripe to see if that's for all.
Rodney #3 had some distinct advantages in the heat context, so I am taking that one forward. Will be back to starting early in the cold next year, so hopefully all will be normal sized, about 40 g fruit.

[bower]

The Skipper Brown F5 det are later than the others and least stable - one of them is a pink-black and one a ribbed mini beef. The tall one, as I expected, dropped more fruit than it set in each cluster. But even with only 3/8 being set, it managed to produce 93 fruit in that time period, compared to 37 and 26 on two other sibs. So being super vigorous does have its advantages, even if you can't self-shelter your blooms from the sun.

[bower]

First taste today, and saved some seeds. The beef-shaped one is outstanding. The pink has complexity but I found the skin bitter even for my taste (I like interesting skins). The tall one similar to last year's may have been underripe - not as sweet as expected. So we'll see how they pan out as I get some more to ripen. Not sure how that will work, being about the equinox already, but we shall see. The locule diversity 5 3 and 2 is like what we were seeing in the F3 growout year.

[Whwoz]

Some more wonderful work and results Bower. Have you ever considered putting some shade cloth over your glasshouse to limit the temperature a bit. White would ythe colour of choice if you can get it

[bower]

I could probably reduce the heat issues somewhat just by using a fan - I have several but omitted that deliberately because I wanted to see what the plants could do in the circumstances.

Overall though, I might get better results by adding a layer of plastic. It's amazing how plastic diffuses the light and you don't get the same scorching effect as under glass. The plastic would help with early season heat retention as well...
Next year I'll be back to starting extra early, let them tough out the cold weather and set their hearts out before it gets too hot.