February 2020 - 7

TRANSPLANTS
CONTINUED FROM PAGE 1
Germination rooms are another
useful tool - especially for crops that
are difficult to germinate. " They're very,
very useful when growing seedless
watermelons, " Coolong said.
Seed trays are put in the germination
rooms for two to three days at uniform
moistures and temperatures with
temperatures of up to 85° F. " You can't
keep large greenhouses that warm, "
Coolong said. Germination rooms also
work when cooler temperatures are
required for crops like fall brassicas
which don't germinate well in midsummer
heat.
Black rot of cabbages and brassicas,
and gummy stem blight and bacterial
fruit blotch of watermelon are the major
seed-borne pathogens in Georgia. " If you
test positive for bacterial fruit blotch,
the whole greenhouse is thrown out, "
Coolong said.
Seed companies do a good job of
testing seed but the system isn't perfect.
Sample size is an issue - typically tests
are only robust enough to determine if
one in 10,000 seeds is infected. Testing
also only identifies pathogens on the
outside of the seed.
Hot water treatment of seed is effective
on bacterial, seed-borne diseases. " Large
growers may even ship their seed out for
hot water treatment, " Coolong said.
Smaller growers can do their own
treatment - if they have the equipment
and skills to precisely control water
temperature and treatment time. For
peppers, the treatment is 30 minutes in
125˚ F water. For tomatoes, it's 25 minutes
in 122˚ F water. Failure to treat at the right
temperature for the right amount of time
can really hurt seed quality.
The Ohio State University Extension
Factsheet " Hot Water and Chlorine
Treatment of Vegetable Seeds to
Eradicate Bacterial Plant Pathogens "
is an excellent guide on hot water
treatment and is available at: https://u.
osu.edu/vegetablediseasefacts/
management/hot-water-seed-treatment/
Hot water treatment only kills
bacteria- and some fungi - on the
seed's surface.
The T-rail system is the most
commonly used support system for
seedling trays in Georgia. " The T-rail
system drives the seedling tray choice
and growers tend to use foam trays in
that system, " Coolong said.
The foam (polystyrene) trays are
lighter than hardened plastic trays and
less likely to damage equipment. Plastic
seedling trays are more durable, easier to
clean and it's also easier to pull seedlings
out of plastic trays.
When using foam trays, some growers
may dip their trays in copper to root
prune seedlings and make pulling
the plants easier. Copper dipping also
prevents root cages.
Root cages are when the roots grow
around in a circle around the outer edges
of a cell. This condition may be caused
by overwatering. Root cages make it
harder to pull the seedlings with wellformed
root balls from the trays.
Seedlings are also harder to remove
from foam cells if the roots have grown
into the cell walls. Plastic trays don't have
this problem. In addition, a perlite layer
on the top of the media in all types of
trays keeps the growing medium from
drying out.
Cell size is an important consideration.
Larger cells hold more media and
can retain more water and nutrients.
Transplants in larger cells need less
frequent watering and fertilizing, and
normally produce stockier and earlier
plants. " A bigger cell means shorter
plants, which generally improves growth
going to the field, " Coolong said.
Smaller cells are generally used
for crops such as cabbage, broccoli,
cauliflower, collard, kale and lettuce.
Larger cells are generally used
for tomato, pepper, watermelon,
Germination rooms are a useful tool - especially for crops that are difficult to germinate.
muskmelon, cucumber and squash.
For tomatoes, it's common to see 128
cells per tray in Georgia although some
growers may use 72. For watermelons, it's
128 or 200 cells per tray. " Growers like
128 but there's more cost, " Coolong said.
" Greenhouse space is at a premium so
many growers use 200. " For peppers, it's
common to see 200 to 242 cells per tray.
Water quality is an issue in Georgia.
There's a lot of limestone in parts of the
state and that gives irrigation water a
high alkalinity.
Alkalinity measures the buffering
capacity of water and is the water's
capacity to resist changes in pH. High
alkalinity is the same as adding limestone
and will cause a rise in pH over time.
Alkalinity is a better measure of how
much acid needs to be added than pH.
" A lot of our growers use sulfuric acid
because it's cheap and readily available, "
Coolong said. " Organic growers use
citric acid which is more expensive. "
Water with a smaller degree of
alkalinity may be effectively modified
with acidifying fertilizers alone.
However, only ammonium-based
nitrogen has an acidifying effect; nitratebased
nitrogen does not.
Application rates for water-soluble
fertilizers applied to greenhouse
transplants through irrigation are usually
specified in ppm (parts per million). It's
important to use the right conversion
tables for accurate application since you
may have to convert per acre spray rates
to greenhouse rates. " Trying to measure
it out on a concentration basis generally
works out better, " Coolong said.
One publication in wide use is UGA's
" Conversion Tables, Formulas and
Suggested Guidelines for Horticultural
Use, " available at: https://hort.caes.uga.
edu/extension/publications-and-factsheets.html
The
bulletin also has guidance on how
much acid to add to correct different
levels of alkalinity. The calculations
will vary with the type of injector being
used. The Electrical Conductivity (EC)
counts the salt ions but the ions could
be from different nutrients.
" A lot of people get EC meters,
but do keep in mind EC is only an
indicator, " Coolong said. " You could
have the same EC but vastly different
nutrient contents. "
Growth regulators are one way
to manage transplant size but again
accurate applications are a must.
" If you don't have the ability to put
out measurements accurately in the
ppm, I'd suggest you not use growth
regulators, " Coolong said. " You must
use them very accurately. " VGN
Siegers...more than seed
STANDOUT
Early to Mid. Resistance: TMV(HR)
TSWV(IR)
, Xcv1-10(HR)
,
Dark, glossy green
extra large to jumbo anthocyaninless
fruit. High quality for place pack segment.
Well adapted for all planting slots.
Stacked disease resistance package.
SIEGERS
EED CO.
(800) 962-4999  www.siegers.com
The Syngenta logo is a registered trademark of a Syngenta Group Company
VGN | FEBRUARY 2020 | 5
EXCLAMATION
90 days. Resistance: Co1(IR)
, Fon1(IR)
17-21 lbs. Full season variety that produces
blocky, firm and sweet flesh, and uniform
size fruit with an attractive rind. Good fruit
set for high yield potential.
OUTSIDER
Early. Resistance: TSWV(HR)
, Xcv1-10(HR)
Glossy-skinned, blocky fruit. Broad disease
package reduces field risk while its early,
concentrated sets of jumbo and extra
large fruit give producers a fast return on
investment.
FASCINATION
85 days. Resistance: Co1(IR)
, Fon1(IR)
16-20 lbs. Rich deep green rind color.
Very classy. Flesh is firm and deep red.
Superior quality, next generation crimson
seedless variety.

https://u http://www.osu.edu/vegetablediseasefacts/ https://hort.caes.uga http://www.siegers.com

February 2020

Table of Contents for the Digital Edition of February 2020