Southeastern U.S. Vegetable Crop Handbook - 2023 - 60

ALTERNATIVE FERTIGATION SCHEDULE
FOR CUCUMBER* (N:K,1:1)
Daily
Days after
planting
Preplant
0-7
8-21
22-63
64-70
nitrogen
1.0
1.5
2.0
1.5
*Adjust based on tissue analysis.
Greenhouse Cucumber Production. If you plan on growing
cucumbers to maturity in the greenhouse, you need to select a
greenhouse variety. This is because these varieties have been
bred specifically for greenhouse conditions - lower light, higher
humidity and temperature, etc., and they have better disease resistance
than field types.
Nearly all greenhouse cucumber varieties are gynecious,
parthenocarpic hybrids. This means that these varieties produce
only female flowers and the fruit are seedless. Since they are
all female, no pollination is needed. The seedless characteristic
makes the fruit very tender to eat. Greenhouse cucumbers are
also thin skinned which makes them more desirable than field
varieties. While non-greenhouse types would grow in the greenhouse,
the yield and quality would be reduced, and therefore
they may not be profitable.
Variety selection is based on yield, fruit size, uniformity,
disease resistance, and lack of physiological disorders, as well
as the market demand for the type grown. In some markets the
long, European types sells better, while in others, the small beit
alpha types, also referred to as " minis " , are preferred. For suggestions
on varieties, see the variety table above. Insect and disease
control methods for greenhouse vegetables can be found in
Tables 2-29 (in the Insect section) and 3-45 (in Disease section),
respectively.
SPECIAL NOTES FOR PEST MANAGEMENT
INSECT MANAGEMENT
Cucumber Beetle: Cucumber beetles can transmit bacterial
wilt; however, losses from this disease vary greatly from field to
field and among different varieties. Pickling cucumbers grown in
high-density rows for once-over harvesting can compensate for
at least 10% stand losses. On farms with a history of bacterial
wilt infections and where susceptible cultivars are used, foliar
insecticides should be used to control adult beetles before they
feed extensively on the cotyledons and first true leaves. Begin
spraying shortly after plant emergence and repeat applications at
weekly intervals if new beetles continue to invade fields. Treatments
may be required until stems begin vining (usually about 3
weeks after plant emergence), at which time plants are less susceptible
to wilt infections.
Pickleworm, Melonworm: Make one treatment prior to fruit set,
and then treat weekly.
Aphids: Aphids transmit several viruses (CMV, WMV, PRSV,
etc.) and can delay plant maturity. Thorough spray coverage
60
DISEASE MANAGEMENT
A. Keinath, Plant Pathologist, Clemson University and R.
A. Melanson, Extension Plant Pathologist, Mississippi State
University
Accurate diagnosis is necessary for effective disease management.
Incorporate appropriate and effective cultural practices
and pesticides, as detailed in the Disease Management section,
in a season-long integrated disease management program.
Cucurbit Downy Mildew (CDM): CDM can be a devastating
disease of cucurbits in the southeastern and eastern U.S. When
possible, plant varieties that have resistance to downy mildew.
Consider planting early to reach spring harvest prior to the arrival
of CDM. Successful CDM management often requires the
use of an appropriate fungicide spray program. A useful tool for
management of CDM is the CDM forecasting system (http://
cdm.ipmpipe.org). This program depends on the accurate reporting
of CDM in the field as well as the monitoring of a network
of sentinel plots throughout the U. S. and Canada by plant
pathologists at various Land Grant Universities. Forecasts of the
movement of the pathogen are generated 3 times a week. Risk
maps are produced from these forecasts. For forecasts, maps,
text alerts, and other helpful information, please visit http://cdm.
ipmpipe.org. If you think you have CDM, please contact your
local Extension office.
Phytophthora Fruit Rot: To minimize the occurrence of this
disease, fields should be adequately drained to ensure that soil
water does not accumulate around the base of the plants. Just
before plants begin vining, subsoil between rows to allow for
faster drainage following rainfall. Apply appropriate fungicides
when fruit are small and susceptible.
Belly Rot: Belly rot is a soil-borne disease. Deep disking or
moldboard plowing to turn over the top few inches of soil will
reduce disease pressure. Application of appropriate crop protectant
at last cultivation may be helpful.
Nematode Management: Various root-knot nematodes, such
as the southern root-knot and guava root-knot, as well as other
nematodes can infect cucumber. Sample soil in fields to be
planted to cucumber in spring during late-summer or fall in the
previous year when nematodes are active. Clean and disinfest
equipment between fields. Use appropriate crop rotations and
cover crops with non-host crops to reduce nematode populations.
Use appropriate fumigants and other nematicides for management
(see fumigant and nematicide tables).
2023 Vegetable Crop Handbook for Southeastern United States
Daily
potash
1.0
1.5
2.0
1.5
Cumulative
Nitrogen
(lb / A)
24.0
31.0
52.0
136.0
150.0
24.0
31.0
52.0
136.0
150.0
Potash
beneath leaves is important. For further information on aphid
controls, see the preceding " Mulching " section. Treat seedlings
every 5 to 7 days or as needed.
Mites: Mite infestations generally begin around field margins
and grassy areas. CAUTION: DO NOT mow or maintain these
areas after midsummer because this forces mites into the crop.
Localized infestations can be spot-treated. Begin treatment when
50% of the terminal leaves show infestation. Note: Continuous
use of pyrethroids may result in mite outbreaks.
http://http:// http://cdm.ipmpipe.org http://cdm http://www.ipmpipe.org
Southeastern U.S. Vegetable Crop Handbook - 2023

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