February 2022 - 25

CONTROLLED ENVIRONMENT AGRICULTURE
or a pad and fan system that cool with
evaporative cooling are also options.
Density planning crucial
Plant density requires a plan.
" If you crowd the plants, the
yield goes down and the number of
imperfections go up, " Snyder said.
Choose a good variety that is
adapted to greenhouse production.
" An outdoor variety may be too
vigorous and limit air flow in the
greenhouse, " Snyder said.
A good variety will likely be red,
indeterminate, have a good yield
and good size, be free of disorders
and have excellent disease resistance
because a greenhouse is a high
humidity environment.
Beefsteak varieties are the standard
but you could also grow Roma
tomatoes, cherry tomatoes, grape
tomatoes and heirloom varieties if
you have a market for them.
" What's the best tomato to grow? "
Snyder asked. " That's the wrong
question. It's what can you sell the
most of at the best price? "
There's a wide choice of growing
media including coconut coir,
rockwool, composted fines of pine
bark and peat-lite mixes.
" Perlite is a good choice, " Snyder
said. " It's not as expensive. "
Using soil as a media can bring
in disease. Sand has a very low
water-holding and nutrient-holding
capacity and isn't a good medium.
Designing an irrigation system
isn't simple. You must select the right
filters and emitters, and plan for
fertigation including the bulk tank
and injector. It may be best to get
help from an irrigation engineer.
" You want to use a greenhouse,
hydroponic, tomato fertilizer, " Snyder
said. " Don't use 20-20-20. It's great
fertilizer but it's for floriculture. "
Tissue test regularly.
Support systems must be strong
because the weight of the tomatoes
and foliage is incredible. Six hundred
plants with fruit load can weigh three
to four tons.
Learn the anatomy of a tomato
plant. Every leaf has a sucker above
it. Remove the suckers once a week
and prune and train the plants to one
main stem. With a string trellis, tie
the top of the string to the overhead,
horizontal wires. Tie or clip the
bottom to the plant's base under a
leaf but not under a flower cluster or
you'll strip off the flower.
You're going to need pollinators
or bumblebee hives and know
how to shake the plants to ensure
pollination.
Flavor comes first
Selling tomatoes locally means
selling on flavor.
Having the right nutrients in the
fertigation water is a key to flavor.
Check the water after you mix
it. Check how much water you're
putting on per day with a gallon jug
under one emitter.
" When a grower comes to me with
a problem, the first question I ask is
'how much water are you putting on?'
and if I get 'I don't know,' that's the
wrong answer, " Snyder said.
Increasing the Electrical
Conductivity (EC), or the amount of
soluble salts in the water, improves
tomato flavor. The pH should
normally be between 5.6 and 5.8 but
lowering the pH when it's close to
picking also improves flavor. Daily
use of a pH meter and an EC meter is
essential.
Vine ripening requires lots of sun.
" Plants turn sunlight into sugar
and the more sunlight, the more
sugar, " Snyder said. " Vine-ripened
tomatoes have more sugar. "
Educate your customers. Tell them
your tomatoes are vine-ripened,
locally grown, healthy, nutritious and
of an excellent quality.
" Know when to harvest, " Snyder
said. " If you're doing retail and
selling daily, pick them red. If the
tomatoes were picked this morning,
tell consumers that. Talk about your
product. "
Resources on greenhouse tomatoes
VEGETABLE GROWERS NEWS
from Mississippi State University can
be found at: http://extension.msstate.
edu/crops/commercial-horticulture/
greenhouse-tomatoes. VGN
TAKE FAST-ACTING CONTROL
OF KEY DISEASES IN YOUR
VEGETABLES SUCH AS
* ALTERNARIA LEAF SPOT
* BLACK DOT (SUPPRESSION)
* DOWNY MILDEW
* EARLY AND LATE BLIGHT
* PURPLE BLOTCH
* WHITE RUST
FOLLOW
VEGETABLE GROWERS NEWS
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VGN | FEBRUARY 2022 | 23

http://www.extension.msstate

February 2022

Table of Contents for the Digital Edition of February 2022