Maybe I forgot those issues - pruning. But we intend to leave 2 main stems, prune off almost every other stem and also prune off most 'under' folia, leaving only the top good leaves.

The plant support will normally be trellis stringing.

I just want to have an idea. Someone told me each plant will yield about 10kg for the season, and that is not the varieties I mentioned, but some unknown varieties

I assume one stem pruning is basically implied. If you can indeed regulate the climate and humidity, which sounds fantastic for your location, and considering those aren't exactly top producing tomatoes (should be good tasting though), I would guess 5-8 kg/plant. I don't have any personal numbers, just from literature.

"considering those aren't exactly top producing tomatoes"

REALY?

From previous researches, I thought these were actually top producing varieties? I'm not really interested in taste, just yield.

What varieties do you reckon are high yielding then @fungus?

You need to be looking into the many varieties bred especially for greenhouse growing and hydroponic growing. Rebelski, Cobra, the BHN varieties, Big Dena, Trust, just to name a few.

I wouldn't consider Chapman a "top producer", Rutgers and Jet Star under normal growing conditions, maybe but there are many that are far better.

Dave

Top producing would be some hybrids. Sure, Chapman and Rutgers are good old variety producers, but they don't stand a chance against modern hybrids. There will be some that will outproduce them 2:1 in a long growing season (especially pruned to one-two stems, which is how all commercial growers grow). Also there is the issue of how well they handle transportation/shelf life, etc, which again is in favor of new varieties. I haven't grown Jetstar, but it is an old hybrid, probably good production, but not top.

I don't have much experience with big fruited hybrids, but everything I've grown from Enza Zaden has been massively good vigour and production. Annamay, which is a premium cocktail tomato, will probably yield as much as Chapman and co (which is a serious feat for a small tomato with superior taste). Their seeds are expensive though. There are many other companies that do good stuff. DeRuiter, Seminis, Hazera, etc. I think you should at least try 5 plants each from various hybrids as a trial for next years, depends what is available in your region also, I know that for some reason these big companies tend to have a localized offer, so what they have for west Europe might be completely different than what they got there (maybe about what they think will do best in certain regions?).

WoW

Seems I made fundamental mistakes from beginning. I researched for high yielding beefsteak and co from hubby growers perspective, not commercial. Thats how I ended up with the varieties I thought were world best in terms of yield.

And I guess again I was shopping for seeds in the wrong websites, because all these names are strange to me, considering all the effort I put in.

Seems I have to open a new thread for people who know including experts here to advice on varieties I should settle for next.

Just In Case, my major requirements are Size and Yield, not interested in taste and shelf life - 10 days shelf life is Ok by me. By size, I guess Beefsteak should be the way to go.

Then I guess I will be needing advice on High Yielding Beefsteak Hybrid Varieties Suited for Hydroponics Greenhouse that will be Pruned to 2 stems in a high Sunlight Region in Africa, - where all other best practices will be maintained, except artificial light and Co2 enrichment. LoL, Very long IMO.

So which websites should I be shopping for these 'commercial' Hybrid Varieties then?

You should stick with Indeterminate varieties for your growing setup, which leaves out Rutgers. With plants properly pruned on a stringline you can realize yields far above what average gardeners on this forum are discussing. You probably should discuss your setup with a university research specialist. Before you start you probably should attend Dr Rick Snyder's (MS)tomato growing workshop.

Unfortunately not many people here or generally tomato forums will have lots of ideas regarding high yield varieties in optimized conditions, simply because it seems commercial and hobby gardeners don't intersect much. I'm pretty sure at least in capitals there are some agricultural shows where interested people can go and see lots of advertisements and maybe even have taste tests and meet people.

I would start to track down a vendor for quality hybrid seed in your region (maybe you have a site?). This can be harder than it seems. For example I look on enza zaden nl site, I see this and that variety, and I have no clue where to find some of them, no website sells them, even in bulk, they are probably available by attending some commercial growers conferences or something. More easily available hybrids are in Eastern Europe, like Poland, Romania, there you can find bulk (100-1000 seeds) for many hybrids, usually the not so expensive ones (those are mostly popular in Nl,Fr,Uk where they can also get premium price for their products). For example a site: http://www.morami.ro/produse-seminte-si-rasaduri-profesionale/plase-si-tesaturi-pentru-agricultura---arrigoni/seminte-profesionale-de-legume-c25.html

If any of them ship to Africa, is another matter.

I don't think by starting with good quality old varieties is necessarily a bad idea, just not optimal, and you will need to trial varieties over the years to see what works best for you, it's just how it goes.

Greenhouse growers on the forums here in NA seem to like the hybrids such as Big Beef, Brandy Boy etc. Their yield is apparently higher than most of the OP varieties.

Here's a link to Johnny's "greenhouse performers" just for interest:

http://www.johnnyseeds.com/search.aspx?searchterm=tomatoes+greenhouse&isusersearch=1

Linda