Leaves- are they really necessary.

[michael johnson]

I have just been reading up on a commercial growers book dealing with commercial crops of tomatoes.

And it states that all leaves can be stripped off the plant once it reaches 1.5 metres high, as they serve no usefull purpose after that -(meaning any leaves below that height) as it states that the plant is unable to complete photosynthesis with the lower leaves being mostly in the shade and and cutting out available light and air to the fruiting trusses, it also goes on to say that all side shoots should be removed all the way up the plant at the earliest conveniance as this leads to much bigger trusses of ripening fruit, the plant can be allowed to go on to 3 metres tall or more- up one side of the greenhouse accross the roof and down the other side.

All tomato plants were laid out in this order:- first cover the floor area with polythene sheeting to prevent any soil borne diseases from coming up out of the soil, then lay on the ground (long polythene sacks or pillows-grow bags of peat) and into the tops of those sacks place three bottomless large pots. with holes cut into the sacks to fit.and then filled with a suitable potting medium.

Plants are fed with a liquid feed from start to finish using a balanced diet of trace elements,Nitrate of potash,Nitrate of ammonia, superphosphate, and urea,

very early crops are obtained by sowing in january and then greenhouses are subjected to C02 gas derived from Kerosene heaters which fill the air with enriched C02 from 8.30 am to 6.30 pm daily for thirteen weeks-during which time crops reach 15 trusses high and a total weight of one and a half tons of tomatoes per hectare.

BER- it also briefly covered this subject and states the cause as being mostly due to drought conditions by incorrect watering-which causes the plant to shed part of its rooting system-and you end up with a very top heavy plant half grown with a lot of leaves on it but no back up roots to support it- the correct solution according to them is to build up compost around the base of the main stem for another four inches or more to encourage further root growth up the stem which then act as water roots and the plant grows away again-it also stated that overhead sprinkling with with a fine rose spray over the top leaves and plant also helped this condition to recover until after the first truss had set and and the plant was returning to normal.

Strangely enough it also said that for best possible fruit set on all trusses and to keep the pollen live and healthy the optimum temp advised was between 13 degrees centigrade and 18 degrees centigrade- anything above and below those temps resulted in dead pollen very quickly, surprisingly low tempratures I would have thought in the mid to low sixties F, but there you have it.

It all makes you think a bit.

[feldon30]

Since you live in the UK, you have a similar growing climate to the Pacific Northwest of the U.S., which sees a lot of rain and grey, drizzly days. You need every bit of sunlight and photosynthesis you can get to get some flavor into the tomatoes.

It is no wonder grocery store tomatoes are so flavorless if they are going to start stripping off leaves en masse.

It's red. CHECK
It's round. CHECK
The skin is rock hard. CHECK
Mission accomplished!

[TomatoDon]

This is a good case of scientific study over ruling common sense. Plant in the dead of winter, strip off the leaves, gas them, and then make a profit. The only problem is you don't have a real tomato. I don't know what you have. A tomato seed coming up in the wild and totally unattended would produce a better fruit than this, ten times over. It would actually be a tomato. Fusion? What's the world coming to?

Don

[michael johnson]

I personaly dont like shop bought tomatoes- as Feldon pointed out they have very tough skins and are mostly tasteless, and I cant bear tough skin tomatoes.

A few years ago there was a commercial variety tomato available called (Concreto) and it was very aptly named- supossed to travel anywhere in the world by air/boat and survive the journey and then have a supermarket shelf life of around a month on top of that- the skins were that tough you could hardly chew them- the flesh was crunchy and solid, it didnt last long in the shops

[amideutch]

Michael, Thats a typical greenhouse, hydroponic growing sytem. Everything is controlled for one thing in mind, "Production". Commercial growers get premium prices for their produce out of season.
One thing I read of interest was that tomatoes go through a period in growth where most of the roots die back. Then they reappear and everything is back to normal. Dr. Cooper from the U.K. discovered this while developing the NFT technique in hydroponics.
One thing to remember is these growers are growing hybrid tomatoes and not the OP heirlooms we are growing. Two different animals. Ami

[feldon30]

Like most good things, the flavor and shelf life of better tomato varieties is fleeting.

[michael johnson]

The most interesting part of the book I was reading was pollen health- I was indeed very suprised that such low tempratures were best for pollen production.

Also the C02 production, it might be good for plants-but not that good for humans, I was wondering if they ventilate the whole building first in order to work and breath in it.

[amideutch]

Michael, they say the optimum levels for CO2 enrichment is 800 to 1200 ppm. Don't know what the concentration has to be before it becomes a problem for airbreathers. I bought a unit which consisted of a regulator and tubing to be used with bottled CO2 but ended up using it for HVAC CS production. Ami

[maryinoregon]

[QUOTE=feldon30;54565]Since you live in the UK, you have a similar growing climate to the Pacific Northwest of the U.S., which sees a lot of rain and grey, drizzly days. You need every bit of sunlight and photosynthesis you can get to get some flavor into the tomatoes.

This is a misperception I fight often. We absolutely do have drizzly days, and very rainy days, but NOT DURING THE SUMMER. Once summer hits here, the rain disappears and usually does not reappear until late September or October. On the east side of the mountains that run through Washington and Oregon, (The Pacific Northwest), there is a lot of desert. Summers are even hotter and drier there.

As near as I can tell, we do have a similar climate to Great Britain in some respects. The northwest is a gardeners paradise. English style country gardens are popular here, (on the west side of the mountains), and my favorite garden store usually sells seed from a number of English companies, as well as American companies.

As for tomato growing, I do plant in the sunniest spots I've got. They get 8 hours max, but that's because I have neighbors with large shade trees. I wish I could give them more sun, because we are not Texas hot, that's for sure. We can actually have a long growing season for warm weather crops, but it doesn't happen every year and we can grow a variety of food crops all year round.

All right, enough from me.

[dice]

[PNW west of the Cascade Mountains:]

"Once summer hits here, the rain disappears and
usually does not reappear until late September
or October."

Except for the 4th of July. Last year was hot
(by our standards) and dry virtually all summer,
but I remember it raining on the 4th fairly often,
even if it was dry for weeks before and after.

It can be dry through most of May, and almost
always for 3 weeks out of 4 in June, July, and
August. End of August and first weeks of September
are iffy.

(At least that has historically been the case.
With recent changes in ocean currents in the
North Pacific and North Atlantic, it is difficult
to guess whether that weather pattern will
persist with its usual consistency.)

[maryinoregon]

Dice, I absolutely agree with you on the Fourth of July. It's not an absolute here in the southern Willamette Valley, but it never surprises me when it rains.

And May, June weather can be surprisingly warm and dry.

Not sure where you are, but July, August are almost always dry the whole month, sometimes September.

[Jonathan_E]

Michael,

Thanks very much for the information. May I ask the name of the book?

Best regards,

Jonathan

[michael johnson]

Yes- the book was called (Tomato Growing- By Reuben Dory) and is purely on commercial growing methods of a few years ago.