From: Brian Lo <dragon@csulb.edu>
Newsgroups: rec.gardens
Subject: FAQ: Cucumbers (Slicing and Markets)
Date: Wed, 1 Mar 1995 14:54:53 -0800
CUCUMBER for FRESH MARKET
Cucumis sativus
(See also file on cucumbers for pickling)
Many excellent cucumbers are available. Flowers may be monoecious
(separate male and female flowers on the same plant) and gynoecious (plants
with only female flowers) and predominantly female (PF) types.
There are also parthenocarpic types (also referred to as burpless or
seedless), they need no pollination. They are also gynoecious or PF. Parthe-
nocarpic or PF types may actually become culls when pollinated since pollina-
tion causes seed to develop and produce misshaped fruit.
Most commercial field-grown cucumbers are monoecious or gynoecious.
With gynoecious varieties seed of a monoecious type is mixed in the seed
package to provide a percentage of plants with male flowers for pollination.
Parthenocarpic and PF types are most commonly used for greenhouse production.
With parthenocarpic types bee colonies need not be used.
VARIETIES (approximately 65-75 days to first harvest).
Slicing: Dasher II, Gemini, Marketmore 80, Slicemaster, Pacer, Sprint,
Triumph, Victory. For trial: Speedway, Turbo, Burpless Bush, and Fanfare (All
America, semidwarf, multiple disease tolerance).
Burpless (European) type: Tasty Green, Sweet Slice - grow these on
trellis for straight fruit. Parthenocarpic type (do not need bees for
pollination): Sweet Success, Euro-American, grow on plastic mulch with row
covers for earliest production or on trellis for straight fruit).
Ethnic markets - Mediterranean: Amira (middle east type, bright green
smooth skin, mild flavor); Armenian cucumber (Cucumis melo also called snake
melon, snake cucumber, and uri) bright green, deeply ridged fruit which can
reach 2 1/2 to 3 feet in length and 2-3 inches in diameter. Oriental: Tasty
Green, Tasty Gift, Tasty Time, Green King, Green Gem, Southern Delight,
Soarer, Tokyo Slicer, Green Knight (all previous listed are 12" to 15" long
and 1 1/2" to 2" in diameter, "burpless"), also Yamato Extra Long (18-24 inch
smooth-skinned, dark green "burpless").
Greenhouse: Seedless (parthenocarpic) types: Corona, Farbio, Femspot,
Pepinex 69, Primio (all female). Bees must be excluded from the production
area, especially when using the predominantly female (pf) types such as Toska.
Regular Types: Any of the cultivars mentioned in the slicing category above
may be used. These field cucumbers require the introduction of beehives in
the greenhouse for proper pollination and fruit set.
Novelty: African Horned Cucumber (Kiwano), orange-fruited spiny spe-
cialty vegetable.
SEED COMPANIES
Abbott & Cobb Inc. POB F307, Feasterville, PA 19047
Asgrow Seed Company, POB 5038, Salinas CA 93915
De Ruiter Seeds Inc. POB 20228, Columbus, Ohio 43220
Elsoms Seeds Ltd. Spalding, Lincolnshire, England PE11 1QG
Enza Seeds POB 7, 1600AA, Enkhuisen, The Netherlands
Ferry-Morse Seed Co. POB 4938, 555 Codoni Ave. Modesto, CA 95352
Harris Moran Seed Co. 3670 Buffalo Rd. Rochester, NY 14624
Nunhems Zaden, Canners Seed Corp. 221 E. Main St. Lewisville, ID 83431
Petoseed Co. Inc. POB 4206, Saticoy, CA 93303
Rijk Zwaan POB 40 2678 ZG DeLier, The Netherlands
Seedless Unlimited, RR2 Townline Rd. Leamington Ontario, Canada N8H 3V5
Stokes Seeds Inc. POB 548, Buffalo, NY 14240
Sunseeds, 2320 Technology Pkwy. Hollister, CA 95023
W. Osborne Seed Co. Int'l. 1679 Highway 99 South, Mount Vernon, WA 98273
Zenner Bros. Seed Co., Inc. 1311 S.E. Gideon St. Portland, OR 97202
SOILS
Cucumbers can be grown on a wide range of soils if the soils are well
drained and have about 2-3% organic matter, and a high level of fertility.
Irrigation is essential to maintain good soil moisture and to obtain high
quality fruit. Avoid heavy soils or those easily compacted. Use a soil test
to determine the nutrient status and pH of the soil.
TEMPERATURE
Recent research indicates that a temperature range of 86-90 F. is
necessary for optimum cucumber growth.
The minimum soil temperature required for germination of this crop is 60
F. with the optimum range between 70 and 95 F. Cucumbers are sensitive to
cool soil conditions. Under such conditions, damping-off can seriously reduce
stands, and seedling growth may be very slow.
SEED AND SEED TREATMENT
Cucumber seed numbers approximately 17,600 per pound. Use treated seed.
Cucumbers can be particularly sensitive to damping-off problems. Seed treat-
ments can dramatically improve stands. Advances in seed priming and film
coating have been shown to improve stand establishment under stress condi-
tions. Consult your seed dealer about the availability of primed seed.
SEEDING AND TRANSPLANTING
Slicing cucumbers are planted or set in the field from early May through
June. With the availability of the less costly plug transplants, there has
been an increasing interest in transplanting.
For direct seeding use 2-3 lb. seed/acre if seeding is to be done with-
out the use of a precision seeder. Precision seeding is highly recommended,
allowing planting to a stand of 7000 to 8000 plants per acre and reducing
seeding rate to about 3/4 lb. to 1 lb per acre.
For transplant production, slicing cucumber varieties are usually
started in individual containers in sterile media in greenhouses 3 to 4 weeks
before transplanting outdoors. Do not transplant until all danger of frost
has passed.
SPACING
Thin direct-seeded plantings of slicing cucumbers, or set transplants to
a spacing of 8-12 inches within the row, and 48-72 inches between rows.
WINDBREAKS
Windbreaks are often overlooked as a crop protection aid. In general,
close windbreaks, even between every row, give the best wind protection and
may moderate the crop micro-climate enough to promote faster plant growth.
Where winter cover crops have been employed, it would be a good practice to
leave strips of the cover crop as windbreaks. In this case, the strips for
the plant beds can be prepared by rototilling, leaving windbreak strips
between the plant rows.
Establishment of a windbreak crop in the previous fall will insure
enough growth to become effective as a windbreak by spring planting time.
Seed grain thickly, 2-3 seeds per inch. This requires about 10 lbs. of
barley, 9 lbs. of wheat, or 8 lbs. of rye to seed grain rows 12 feet apart.
Spring grains such as barley may be useful if planted in February in eastern
Oregon.
Windbreaks can be removed by mowing, tilling, or an appropriate herb-
icide once their useful life is over.
FERTILIZER
Good management practices are essential if optimum fertilizer responses
are to be realized. These practices include use of recommended varieties,
selection of adapted soils, weed control, disease and insect control, good
seed bed preparation, proper seeding methods, and timely harvest.
Because of the influence of soil type, climatic conditions, and other
cultural practices, crop response from fertilizer may not always be accurately
predicted. Soil test results, field experience, and knowledge of specific
crop requirements help determine the nutrients needed and the rate of applica-
tion.
The fertilizer program should insure adequate levels of all nutrients.
Optimum fertilization is essential for top quality, yields, and returns.
Recommended soil sampling procedures should be followed in order to
estimate fertilizer needs. The OSU Extension Service agent in your county can
provide you with soil sampling instructions and soil sample bags and informa-
tion sheets.
Recommendations are based on a row spacing of 60". With decreased row
spacings fertilizer rates should be increased.
Western Oregon:
NITROGEN (N)
When available, apply 10 Tons of manure per acre.
Use 80 to 150 lb N/A, with the lower rates of N being applied when
legumes were grown the preceding year or a green manure crop is incorporated
into the soil prior to planting. Apply one-half the nitrogen at or just prior
to planting and the rest when vines begin to "run".
Exercise care in nitrogen fertilization. Excess nitrogen may result in
viney plant growth which interferes with bee pollination and harvest, and
promotes foliar and fruit diseases, resulting in reduced fruit set.
Cucumbers are sensitive to fertilizer burn. If the application of N
plus potash (K2 O) exceeds 50 lb/A, there is danger of seedling injury from
the fertilizer if it is all banded at planting time.
There is less danger if the band application is split into two bands.
The danger is aggravated as the band comes closer to the seed, and is greater
with sandy than with finer textured soil. Immediate irrigation at the first
sign of burn should reduce further injury. There is more possibility of
damage to seedlings on acid soils where the pH is below 5.5.
PHOSPHORUS (P)
Phosphorus fertilizer should be banded at planting for vigorous early
seedling growth. Bands should be located 2" to the side and 2" below the
seed.
If the OSU soil test Apply this amount of
for P reads (ppm): phosphate (P2 O5 (lb/A):
0 to 15 120-150
l5 to 60 90-120
over 60 60-90
In some areas, a diluted phosphoric acid solution sprayed in a 1-2 inch
wide band directly over the seed row has shown to reduce crusting, improve
phosphorus nutrition of the crop and increase yield. The benefit of this
treatment would be most likely to occur with early plantings on cool soils.
POTASSIUM (K)
Potassium for both hand and machine harvested fields should be applied
before planting or banded at planting time. Amounts above 40 lb K2 O/A should
be broadcast and worked into the seedbed. See statements on fertilizer
banding under "NITROGEN".
If the OSU soil test Apply this amount of
for P reads (ppm): potash K2 O (lb/A):
0 to 75 100-150
75 to 150 60-100
150 to 200 40-60
over 200 0
SULFUR (S)
Include 20-30 lb S/A in the annual fertilizer program for vine crops. S
is sometimes contained in fertilizers used to supply other nutrients such as
N, P, and K but may not be present in sufficient quantity.
Plants absorb S in the form of sulfate. Fertilizer materials supply
sulfur in the form of sulfate and elemental S. Elemental S must convert to
sulfate in the soil before the S becomes avail able to plants. The con-
version of elemental S to sulfate is usually rapid for fine ground (less than
40 mesh) material in warm moist soil.
Sulfur in the sulfate form can be applied at planting time. Some S
fertilizer materials such as elemental S and ammonium sulfate have an aci-
difying effect on soil.
MAGNESIUM (Mg)
When the soil test value is below 1.5 meq Mg/100g of soil or when
calcium (Ca) is ten times more than the Mg, apply 10-15 lb Mg/A banded at
planting. If Mg deficiency symptoms appear, spray with 10 lb Epsom salts in
100 gals of water/A.
Magnesium can also be supplied in dolomite, which is a liming material
and will reduce soil acidity. Dolomite should be incorporated into the
seedbed at the rate of 1-1 1/2 T/A.
BORON (B)
In general, boron deficiencies are uncommon. If the soil test value for
B is less than 1 ppm, an application of 3 lb B/A is suggested. Boron should
be applied uniformly to the field as a spray or broadcast. Never band B
fertilizer.
ZINC (Zn)
Zinc deficiencies are uncommon in Willamette Valley soils. When the
soil test is below 1 ppm Zn, a response to Zn is expected and 4 lb Zn/A should
be included in the fertilizer band.
LIME
Experimental work has shown that vine crops will produce good yields
over a fairly wide range of soil acidity. Lime applications are suggested
when the soil pH is 5.6 or below, or when calcium (Ca) levels are below 5 meq
Ca/100g of soil. Optimum pH is between 5.8 and 7.0.
The rate of lime application can be estimated from the following OSU SMP
buffer table.
If the OSU SMP buffer Apply this amount of
test for lime reads: lime (T/A):
Below 5.2 4-5
5.2 - 5.6 3-4
5.6 - 5.9 2-3
5.9 - 6.2 1-2
The liming rate is based on 100-score lime.
Lime should be mixed into the soil at least several weeks before plan-
ting. A lime application is effective over several years.
Some soils may have a fairly high OSU SMP buffer value (over 6.5) and a
low pH (below 5.5). This condition can be caused by the application of
acidifying fertilizer. In this case the low pH value is temporary and the pH
of the soil will increase as the fertilizer completes its reaction with the
soil. This temporary "active" acidity from fertilizer is encountered follow-
ing recent applications of most N fertilizer materials. Acidifying fertiliz-
ers also have a "long term" acidifying effect on soil which is cumulative and
leads to lower OSU SMP buffer readings.
Sandy soils to which fertilizers have not been recently applied some-
times record low pH and high SMP buffer values. In such cases, a light
application of 1-2 T/A of lime should suffice to neutralize soil acidity.
For acid soils low in Mg (less than 0.8 meq Mg/100g of soil), 1 T/A of
dolomite lime can be used as a Mg source. Dolomite and ground lime stone have
about the same ability to neutralize soil acidity.
The possibility of seedling injury from the band application of ferti-
lizer is less when the soil pH is 5.6 or above. Some Willamette Valley
experiments have shown decreased uptake of phosphorus from band applications
of phosphorus when the pH approaches 5.5.
Lime applications should be broadcast, preferably in the fall, and
incorporated into the seedbed. Do not plow lime down leaving the surface soil
unlimed.
Fertilizer Guide #2, "Liming Materials for Oregon", which is available
from your local OSU Extension Office, provides additional information lime.
Eastern Oregon:
At time of seeding or transplanting, band the following:
Nitrogen: 80-150 lbs. nitrogen/acre. Apply two-thirds of this during
the last half of the crops growth, with the first side-dress at the time the
vines begin to runner.
Phosphate: 100-150 (P205) lb/acre
Potash: 50-70 (K20) lb/acre
Where mulching and trickle irrigation are practiced nitrogen can be
fed through the trickle irrigation system at 20 lb./acre when the vines
begin to spread. To prevent clogging or plugging from occurring use
soluble forms of nitrogen (Urea or Ammonium nitrate) and chlorinate the
system once a month with a l0-50 ppm chlorine solution. Chlorinate more
frequently if the flow rate decreases.
These fertilizer recommendations are based on research conducted by OSU
Horticulture and Soils Department and Extension faculty, and are quoted from
OSU Fertilizer Guide FG 68.
FLOWERING AND POLLINATION
Depending on cultivar, cucumbers plants may bear separate male and
female flowers on the same plant (monoecious), only female flowers (gyno-
ecious), or male flowers and perfect flowers (male and female organs in the
same flower) i.e. andromonoecious. Most modern cultivars have plants that
bear only female flowers (gynoecious), so seeds of plants that are monoecious
(bearing separate male and female flowers on the same plant) are mixed into
the seed lot (usually 10 to 15%) to allow pollination. These seeds are
usually dyed a different color from the seeds of the cultivar being planted.
Bees are needed to transfer pollen from the male flowers to the female
flowers, thus making fruit set possible. Cucumbers are not pollinated by
wind. It is recommended that 1-2 honey bee colonies of 30,000 to 50,000 bees
each be introduced for every acre during the blooming period.
Naturally occurring bee populations are not considered to be adequate
since their presence may not coincide with the full blooming period, or their
numbers may be too low. Information from the midwest indicates that cucumbers
require at least 15 bee visits to each flower for normal pollination and fruit
set, and maximum yields, although some of the new all-female varieties may set
as much as one-third of their yield without being pollinated.
Hives should be placed at the edge of the field after the first blooms
are visible so that no point in the field is more than 200-300 yards away from
a colony. Placing bees prior to flowering may result in the bees establishing
themselves on nearby crops thus reducing their effectiveness in cucumber
pollination. Research indicates that total yield increases resulting from
good bee management can range from 25 to 50 percent.
PLASTIC GROUND MULCHES AND ROW COVERS
Use of plastic mulch and trickle irrigation has been shown to be very
effective with both transplanted and direct seeded slicing cucumbers. Early
and total yields are increased and more than compensate for the increased
cost. A new generation of plastic mulch films allows for good weed control
together with soil warming that is intermediate between black plastic and
clear film. These films are called IRT (infra-red transmitting) films. They
are more expensive than black or clear films, but appear to be cost-effective
where soil warming is important.
Spunbonded polyester and polypropylene, and perforated polyethylene row
covers may be used for 4 to 8 weeks immediately after seeding or transplant-
ing. Covers should be removed when plants begin to flower to allow proper
pollination by insects. Row covers increase heat unit accumulation by 2 to 3
times over ambient. Two to four degrees of frost protection may also be
obtained at night. Soil temperatures and root growth are also increased under
row covers as are early yields, and in some cases total yields.
SOIL SUPPORTED COVERS
Preliminary research in California indicates that soil supported covers
or mini-tunnels have been used to promote early production of tomatoes, at a
minimum of cost. This technology would have similar application in a number
of other crops. Similar to hoop supported tunnels, these increase soil and
air temperature around the plants, maintain surface soil moisture, and prevent
crusting. They may also provide about 7 days advantage in earliness and har-
vest season, depending on crop and time of planting.
Soil to form the sides of the tunnel is brought from the sides of the
plant row which may be direct seeded or transplanted at the same time, or
prior to tunnel installation. A modified bedshaper is used to form a ridge on
each side of the plant row, leaving a suitable area for planting. A 36 inch
wide piece of embossed clear plastic is then used to cover the plant row,
leaving a 5 to 6 inch high space between the planted row and the plastic
cover. It is estimated that temperatures may be increased 10-20 F. depending
on time of planting and sunlight availability and intensity.
IRRIGATION
Irrigation requirements depend on the length of harvest. Some fields
may be hand harvested 10-12 times and need to be kept growing adequately. Ten
to fifteen inches of water may be required depending on seasonal variation and
variety. Irrigations need to be coordinated with picking schedules.
Soil type does not affect the amount of total water needed, but does
dictate frequency of water application. Lighter soils need more frequent
water applications, but less water applied per application.
HARVESTING AND HANDLING
Slicing cucumbers are generally harvested in western Oregon from mid
July through September, however, weather permitting, they can be harvested
well into October. East of the Cascades, harvest may begin about 2 weeks
earlier.
Approximate yields of fresh market (slicing) cucumbers are 115 cwt./acre
with good yields about 250 cwt./acre. For highest returns, thoroughly harvest
marketable fruit at regular intervals. Remove oversize fruit so later fruit
can develop properly. During warm weather conditions, cucumbers may grow very
rapidly and it is important to shorten harvest intervals.
STORAGE (Quoted from USDA Ag. Handbook #66):
Cucumbers can be held 10 to 14 days at 50 to 55 F with a relative humi-
dity 90-95%. They are subject to chilling injury if held longer than about 2
days at temperatures below 50 F. At temperatures of 50 f and above, they
ripen rather rapidly, the green color changing to yellow. This color change
starts in about 10 days at 50 F and is accelerated if the cucumbers are stored
in the same room with apples, tomatoes, or other ethylene-producing crops.
Modified atmospheres, particularly with low oxygen (5 %), will retard yellow-
ing.
Cucumbers are vary susceptible to shriveling; hence, the humidity in the
storage should be kept high. Cucumbers for the fresh market are usually waxed
to reduce moisture loss. Shrink-wrapping with polyethylene film can also
delay the loss of turgidity.
Symptoms of chilling injury are water-soaked spots, pitting, or tissue
collapse. A surge in ethylene production may occur and extensive decay will
develop when chilled cucumbers are removed from low-temperature storage.
PACKAGING
Slicing cucumbers are commonly packaged in 55 lb. l-l/9 bushel cartons
and wirebound crates; 47-55 lb. bushel cartons and wirebound crates; 26-32
lb. cartons, or 28-32 lb. L. A. lugs.
PEST CONTROL FOR CUCUMBER
THE PESTICIDES LISTED BELOW, TAKEN FROM THE PACIFIC NORTHWEST PEST
CONTROL HANDBOOKS, ARE FOR INFORMATION ONLY, AND ARE REVISED ONLY ANNUALLY.
BECAUSE OF CONSTANTLY CHANGING LABELS, LAWS, AND REGULATIONS, OREGON STATE
UNIVERSITY CAN ASSUME NO LIABILITY FOR THE CONSEQUENCES OF USE OF CHEMICALS
SUGGESTED HERE. IN ALL CASES, READ AND FOLLOW THE DIRECTIONS AND PRECAUTION-
ARY STATEMENTS ON THE SPECIFIC PESTICIDE PRODUCT LABEL.
USE PESTICIDES SAFELY!
Wear protective clothing and safety devices as recommended on the label.
Bathe or shower after each use.
Read the pesticide label--even if you've used the pesticide before. Follow
closely the instructions on the label (and any other directions you have).
Be cautious when you apply pesticides. Know your legal responsibility as a
pesticide applicator. You may be liable for injury or damage resulting from
pesticide use.
WEED CONTROL
When black plastic ground mulch is not used, cultivate as often as
necessary when weeds are small. Proper cultivation, field selection and
rotations can reduce or eliminate the need for chemical weed control.
______________________________________________________________________________
ACTIVATED CHARCOAL SEED PROTECTION
Several Pacific Northwest grass seed crops are protected from herbicide injury
with the use of activated charcoal which adsorbs and detoxifies or inactivates
the herbicide. In vegetables, activated charcoal can be mixed with horticult-
ural grade vermiculite and applied as an anticrustant/seed protectant. The
activated charcoal vermiculite mix is placed within the seed furrow using a
positive feed device. Herbicides must not leach excessively or move readily
from crop roots into the plant. Although crop safety can be enhanced, weeds
emerging from within the treated area also are protected.
Another use for activated charcoal involves seed protection from herbicides
that leach into the seed zone from excessive rainfall. Seed coatings of
activated charcoal would reduce the active concentration of herbicide at or
very near the seed during the germination process.
Activated charcoal/vermiculite mix: Thoroughly mix 1 lb activated
charcoal/ft3 of number 2 or 3 grade horticultural
vermiculite. If severe dustiness is a problem, add a
small amount of water. Apply 1 ft3 of mixture/600 ft.
of seeded row or approximately 15 cu.ft/A. Fill the
seed furrow using a positive feed applicator and press
with a press wheel.
WEED MANAGEMENT GENERAL STRATEGY
Weed management in cucurbits represents planning and integration of several
practices. Crop rotations and, therefore, field selection containing control-
lable weeds must be achieved before planting. Many growers use a stale
seedbed technique followed by cultivation, except in excessively wet years.
Row spacings that enhance canopy development and cultivation are sometimes
supplemented with a herbicide that selectively controls weeds within the
crop row. In eastern Oregon, rye windbreaks often are planted between rows
and incorporated during the last cultivation.
______________________________________________________________________________
STALE SEEDBEDS FOR VEGETABLE PRODUCTION
Stale seedbeds are sometimes used for vegetable production when other selec-
tive weed control practices are limited or unavailable. The concept depends
on controlling the first flush of emerged weeds before planting or emergence
of the crop followed by minimal soil disturbance which reduces subsequent weed
flushes during establishment of the crop. Following establishment, other weed
control practices including cultivation or use of other herbicides can be
used.
1. Prepare a seedbed, preferably 2 to 3 weeks before planting to achieve
maximum weed seed germination near the soil surface. Soil temperatures
and moisture must be reasonable or results will be erratic.
2. Plant the crop with minimum soil disturbance. Otherwise, new weed seed
will be exposed to favorable germinating conditions.
3. Just before or after planting but before crop emergence, treat the
field by flaming or with herbicide to kill all germinated or exposed
weeds.
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
Flaming
Use liquid propane or similar fuel-burning equipment to quickly sear the
weeds, but not consume them with flame.
------------------------------------------------------------------------
paraquat 0.625 to 0.94 lb ai/A
Gramoxone Extra
(see remarks)
Restricted-use pesticide. Do not ingest or inhale spray mist. Wearing
protective face shields, respirators, and clothing is advised. Apply
during or after planting, but before crop emergence. Add a nonionic
surfactant or crop oil concentrate according to label specifications,
taking care to avoid anionic formulations that react in the tank to form
insoluble precipitates. Exposed crop plants will be killed. Do not
apply preplant or pre-emergence to soils lacking clay minerals, such as
peat, muck, pure sand, or artificial planting media. (Acts as contact;
absorbs energy produced by photosynthesis forming peroxides that disrupt
living cells.)
______________________________________________________________________________
PREPLANT INCORPORATED
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
Bensulide 5 to 6 lb ai/A
Prefar
Apply preplant and incorporate 0.5 to 1 inch deep simultaneously or
immediately after application by cross-disking or using a PTO rotary
tiller. Sometimes the first flush of weeds must be controlled with
cultivation before herbicide begins to control grass. Consult label for
planting sensitive crops within 18 months. Do not apply more than once
every 12 months. (Inhibits roots of seedlings).
------------------------------------------------------------------------
bensulide + 4 to 6 lb
naptalam +
Prefar + Alanap 2 to 4 lb ai/A
Note inforamtion above for bensulide and below for naptalam. Use lower
rates on sandy soils.
______________________________________________________________________________
PREEMERGENCE
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
naptalam 3 to 4 lb ai/A
Alanap
Apply immediately after seeding to moist soil and sprinkler irrigate
with 0.5 to 1 inch water or mechanically incorporate in 1 to 1.5 inches
soil with spiketooth harrow to place herbicide in germination zone. Use
lower rates on sandy soils. Controls primarily broadleaf weeds.
(Reverses geotropism in roots).
------------------------------------------------------------------------
ethalfluralin 1.12 to 1.69 lb ai/A
Curbit
Adjust rates depending on soil texture and organic matter. Apply only
as a postplant surface treatment before weed emergence. Activate with
0.5 inch irrigation within 2 to 5 days or cultivate soil surface above
seed. Crop injury may occur with excessive rainfall or irrigation or if
seeding depth is too shallow. Do not graze, nor apply to wet or cloddy
soils. Note replanting restrictions for sugar beets and red beets
listed on label. (Inhibits mitosis, primarily in shoots.)
______________________________________________________________________________
POSTEMERGENCE
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
sethoxydim 0.19 to 0.28 lb ai/A
Poast
Identify susceptible grasses and apply at optimum growth stage listed on
the label. Add 2 pints/A nonphytotoxic crop oil concentrate to improve
leaf absorption. Erratic control often occurs when grasses are stunted
or stressed from drought, high temperatures, or low fertility. Resis-
tant grasses include annual bluegrass and all fine fescues, whereas
quackgrass can be suppressed. Do not apply within 14 days of harvest,
nor exceed 3 pints/A per season. (Inhibits fatty acid production, cell
membranes, and new growth.)
______________________________________________________________________________
POSTEMERGENCE LAY-BY TREATMENTS
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
trifluralin 0.5 to 0.75 lb ai/A
Treflan
Apply as a directed spray between rows when crop has 3 to 4 true leaves
and incorporate 2 to 3 inches deep, using rolling cultivators set
to throw soil towards plants in the row. Spray only 1 time per year.
Consult label for restrictions on planting sensitive crops within 12
months. Possible injury may result in cool soils and from carryover from
repeated use without adequate rotation. (Inhibits mitosis, primarily
in shoots).
------------------------------------------------------------------------
ethalfluralin 1.12 to 1.69 lb ai/A
Curbit
Adjust rates depending on soil textures and organic matter. Apply in
bands between rows after planting or transplanting. Activate with
0.5 inch irrigation within 2 to 5 days or cultivate soil 1 to 2 inches
deep. Do not graze or apply to wet cloddy soils. Note replanting re-
strictions for sugar beets and red beets listed on label. (Inhibits
mitosis, primarily in shoots.)
------------------------------------------------------------------------
DCPA 9 lb ai/A
Dacthal
Performs poorly in western Oregon and Washington. Elsewhere, apply
after plants have 4 to 5 true leaves following a cultivation and
weeding, but before any new weeds become established. Results are
improved if rainfall or overhead irrigation occurs immediately after ap-
plication. Consult label for restrictions on planting sensitive crops
within 8 months. (Inhibits mitosis).
______________________________________________________________________________
______________________________________________________________________________
INSECT CONTROL
Proper rotations and field selection can minimize problems with insects.
THE PESTICIDES LISTED BELOW ARE TAKEN FROM THE PACIFIC NORTHWEST INSECT
CONTROL HANDBOOK, AND ARE FOR INFORMATION ONLY. CONSULT PRODUCT LABELS FOR
CURRENTLY LEGAL REGISTRATIONS, RATES AND COMPLETE INSTRUCTIONS.
Insect and Description Control, Active Ingredient Per Acre
---------------------------------------------------------------------------
Aphids, including diazinon - 0.5 lb spray
Bean aphid
Aphis fabae malathion - 1.25 lb
Dull black plant louse that colo- Phosdrin - 0.25 lb
nizes during latter part of the
season. Pyrellin - 1 to 2 pt
Melon aphid Dibrom - 1 lb
Aphis gossypii
Metasystox-R - 0.5 lb
Small plant louse, yellowish to
dark green in color. Pale forms endosulfan - 0.5 to 1.0 lb
have dark mottling. Colonize
plants late in the season. NOTE: Bees are important in cross
pollination of cucumbers. Take
Potato aphid precautions to avoid poisoning
Macrosiphum euphorbiae them. See; "How to Reduce
Poisoning of Bees from Pesti-
Green to pinkish plant louse that cides."
colonizes plants. Transmits virus.
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Cucumber beetles methoxychlor - 1 to 3 lb
Small, slender, greenish-yel- diazinon 0.5 lb
low beetles with three promi-
nent black stripes on back. At- malathion - 1 to 1.5 lb
tack young plants. Larvae feed
on roots and underground carbaryl - 1 lb
parts of stems.
Dibrom - 1 lb
OR
Yellowish-green, black-spotted endosulfan - 0.5 to 1 lb
beetle, common to western
Oregon and southwestern Guthion - 0.5 lb
Washington. Damage usually
limited to young plants. Asana - 0.03 to 0.05 lb
Lannate - 0.45 to 0.9 lb
Pyrellin - 1 to 2 pt
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Cutworms Lannate - 0.45 to 0.9 lb
Many species
Asana - 0.03 to 0.05 lb
Small to large larvae that feed
on foliage and stems. Sevin bait 5% pellets - 1 lb
---------------------------------------------------------------------------
Cabbage looper Lannate - 0.45 to 0.9 lb
Trichoplusia ni
Dibrom - 1 to 2 lb
Pale green larvae with white
stripes. Move in looping manner. Asana - 0.025 to 0.05 lb
---------------------------------------------------------------------------
Grasshoppers Asana - 0.03 to 0.05 lb
Different species
Nosema locustae - use as
manufacturer directs
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Seed corn maggot Seed Treatment
Delia platura Lorsban 50 SL - 1 oz ai/100 lb
of seed.
Small legless maggot that feeds on
and destroys germinating seeds.
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Slugs metaldehyde baits. Do not contami-
nate edible plant parts.
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Spider mites Kelthane 35W - 0.6 lb Do not
Tetranychus spp. feed or use EC formulations.
Tiny spiderlike animals that malathion - 1 to 1.9 lb
feed on plant juices causing
leaves to turn yellow and die. Metasystox-R - 0.5 lb
Phosdrin - 0.5 lb
Dibrom - 1 lb
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Garden symphylan Telone II or C-17 preplant
Scutigerella immaculata
Small, white, centipede-like
animals in soil.
--------------------------------------------------------------------------
Thrips diazinon - 0.5 lb spray
Very small, slender insects. Dibrom - 1 lb
Pale green (young) to black (adults).
Feed on leaf surfaces. Surface feeding
causes leaves to appear silvery.
---------------------------------------------------------------------------
Wireworms diazinon - 3 to 4 lb active
Limonius spp. ingredient per acre. Broadcast
granules or emulsifiable
Brown, jointed larvae of click formulations evenly on the soil
beetles. Kill young plants, surface and incorporate into
weaken older ones. the top 4-8 inches of soil.
Telone II or C-17
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DISEASE CONTROL
Proper rotations, field selection, sanitation, spacings, fertilizer and
irrigation practices can reduce the risk of many diseases. Fields can be
tested for presence of harmful nematodes. Using seed from reputable seed
sources reduces risk from seed born diseases.
THE PESTICIDES LISTED BELOW ARE TAKEN FROM THE PACIFIC NORTHWEST DISEASE
CONTROL HANDBOOK, AND ARE FOR INFORMATION ONLY. CONSULT PRODUCT LABELS FOR
CURRENTLY LEGAL REGISTRATIONS, RATES AND COMPLETE INSTRUCTIONS.
CUCUMBER -- ALTERNARIA LEAF SPOT (Fungus Leaf Spot)
Cause: A fungus, Ulocladium consortiole. Recent work in Washington has shown
this disease does not reduce yields under Washington conditions.
Symptoms: Small tan spots which turn dark brown on maturing. Often concentric
rings may be noticed in the older spots giving them a "bull's-eye" appearance.
Coalescing spots may involve large areas of the leaf. Under Northwest condi-
tions the fruit have not been attacked by this organism.
~Control: Use one of the following sprays:
1. Bravo 720 at 2 to 3 pt/A in water to cover. May be applied by sprinkler
(see product label).
2. Mancozeb at 1.8 to 2.4 lb ai/A. Do not apply within 5 days of harvest.
3. Maneb at 1.2 to 1.6 lb ai/A. Do not apply within 5 days of harvest.
---------------------------------------------------------------------------
CUCUMBER -- ANGULAR LEAF SPOT
Cause: Pseudomonas syringae pv. lachrymans lacrymans, a bacterium. The
bacterium overwinters in diseased plant material and on the seed. It is spread
by rain, sprinkle irrigation, or on hands and clothing of workers. In recent
years the incidence of the disease has been reduced by the use of tolerant
varieties.
Symptoms: Leaves, stems, and fruits may be affected. The leaf spot is irregu-
lar in shape, angular, with a water-soaked appearance. Bacteria may ooze from
the spots in droplets which dry to a white residue. The water-soaked area
later turns gray and dies. Often the dead tissue is torn away from the healthy
portion of the leaf leaving large irregular holes.
The water-soaked spots on the fruits are smaller and circular. Lesions are
usually superficial, but the injury may permit the entrance of soft-rot
organisms.
The affected tissue becomes white and may crack open.
~Control: The following control program is a combination of those used in other
areas.
1. Plant resistant varieties. Pickling varieties `Regal', `Royal', `Calypso',
`Pioneer', `Express', `Cross Country', and `Frontier', have shown tolerance
under Washington and Oregon conditions. The use of these varieties is usually
sufficient under our conditions. The slicing varieties `Victory', `Bel Aire',
`Raider', `Encore', `Poinsett 76', `Slice Nice', `Dasher II', `Turbo',
`Quest', and `Sprint-N' are resistant.
2. Stay out of wet, infected fields.
3. Application of fixed copper spray has reduced the spread of the diesase,
but copper sprays have been reported to cause some stunting and leaf chlorosis
in Oregon. Several copper materials are available.
Residues:
Arasan--considered to be a nonfood use.
Captan--seed treatment, considered a nonfood use.
Coppers--exempt.
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CUCUMBER -- BACTERIAL WILT
Cause: Erwinia tracheiphila, a bacterium, which overwinters in the bodies of
the striped and 12-spotted cucumber beetles. In Oregon, the disease occurs on
cucumbers occasionally. The bacterium affects only plants belonging to the
cucumber family--cucumbers, muskmelons, pumpkins, squashes, gherkins, white
gourds, and a number of wild plants.
There is a very close relationship between the bacterium and the beetles--if
the beetles are eliminated so is the bacterium. The bacterium hibernates in
the digestive tract of a few beetles and in the spring finds its way through
the feces of the carriers to the young plant. It can enter the plant tissue
only through deep wounds such as injuries produced by feeding beetles, or
later in the season, following grasshopper invasion. The bacteria are not
carried in or on the seed.
When beetles chew on affected leaves, which they seem to prefer, their mouth
parts become contaminated with the bacteria, which are carried to the next
three or four plants on which the beetle feeds. Infection takes place only
when there is a film of water sufficient for the pathogen to reach the wound
in the inner leaf tissue.
The beetles do not migrate in rainy periods; the disease rarely is found where
the annual rainfall is over 45 inches or below 18 inches. Optimum average
daily temperatures for development of the disease are 52o to 60o F.
Symptoms: General wilting of the plant. Infection begins on one or a few
leaves which droop suddenly. The disease spreads from the foliage downward
into the petioles and stems until the plant has wilted and died. The fruit
also wilts and shrivels.
~Control: Spraying or dusting to control the carrier beetles is effective.
See Pacific Northwest Insect Control Handbook.
---------------------------------------------------------------------------
CUCUMBER -- CURLY TOP
Cause: A virus disease spread by the beet leafhopper and surviving from year
to year in perennial weed hosts.
Symptoms: Growth is retarded and the older leaves take on a tan-yellow color.
Terminal leaves are sometimes darker than normal, and the entire plant is
stunted. The few fruits produced are small, of poor quality, and abnormally
shaped.
~Control:
1. Set out more plants than needed and remove diseased plants as soon as they
can be detected.
2. Partial shading will discourage movement of the leafhopper vector onto the
plants, thus reducing the possibility of infection.
3. There are no known resistant varieties.
---------------------------------------------------------------------------
CUCUMBER -- DAMPING-OFF
Cause: This disease is caused by the fungus Pythium ultimum, which lives in
the soil. It attacks seedlings of many different crops.
Symptoms: Seedlings may be attacked before they emerge or after they are up,
resulting in gaps and uneven stands. Young plants suddenly wilt and topple
over. Water-soaked lesions are apparent on the stems at the soil line. As the
seedlings mature, they become resistant to attack. The disease can be a
serious problem in cool, wet soils.
~Control:
1. Delay planting until soil warms so as to increase seedling growth and
emergence.
2. Mulch soil to increase soil temperature.
3. Plant shallow to promote quick emergence and growth.
4. Treat seed with captan.
5. Treat seed with Apron FL 1.5 fl oz/cwt (Pacific Northwest states only).
6. Treat seed bed with Ridomil 2E
Broadcast: Apply 4 to 8 pt Ridomil 2E/treated A at planting in 20 to 50 gal of
water.
Banded: Apply Ridomil 2E in a 7-inch band. Rates are calculated based on row
spacing and plant density according to the label. Broadcast and incorporated:
Apply 4 to 8 pt of Ridomil 2E/A as a broadcast soil application in 20 to 50
gal of water and incorporate in the top 2 inches of the soil. If beds are
used, broadcast and incorporate prior to bedding.
Seed treatment: Apply Anchor at 1.502/cwt seed.
---------------------------------------------------------------------------
CUCUMBER -- GUMMY STEM BLIGHT
See Squash--Black Rot or Gummy Stem Blight
---------------------------------------------------------------------------
CUCUMBER -- MOSAIC
Cause: A virus disease spread by aphids and possibly cucumber beetles. The
virus overwinters in the seed of wild cucumber and in wild perennial milkweed,
ground cherry, and matrimonial vine.
Symptoms: Leaves are markedly mottled and wrinkled with yellow and green
blotches and edges cupped downward. Early season infection results in dwarfing
of the plants while later infections show the typical mosaic symptoms only on
later season growth following infection. The fruit develops raised wartlike
bumps with pale, whitish-green areas between, and has a bitter taste. Some
varieties of small, later fruits have a pale greenish-white appearance.
~Control:
1. Remove all infected vines.
2. Remove wild cucumber vines, milkweed, and other susceptible weed hosts to
within 1,000 feet of the field if possible.
3. Control aphids by spraying or dusting.
4. In slicing cucumber varieties, `Niagara' is resistant. There is also some
tolerance to the virus in the following hybrids--`Burpee', `Surecrop',
`Gemini', `Marketmore', and `Sensation'. For pickling cucumbers, the varieties
`MR-17', `SMR-18', `SMR-58', and `Pioneer' have high tolerance and are
recommended for planting.
---------------------------------------------------------------------------
CUCUMBER -- NEMATODE (Root-Knot)
See Tomato--Nematode (Root-Knot) for a further description of cause and
symptoms.
~Control: Mocap 10E (20 lb/A) or Mocap EC (1 to 1.5 qt/A) in a band 12 to 15
inches wide on the row at or just before planting. Do not use a seed furrow
treatment.
---------------------------------------------------------------------------
CUCUMBER -- POWDERY MILDEW
Cause: A fungus, Erysiphe cichoracearum.
Symptoms: At first tiny, white superficial spots appear on the leaves and
stem. The spots become powdery white and expand to cover all portions of the
plant. Sometimes the mycelium becomes covered with small black spots about the
size of a pinhead. Usually the disease occurs in scattered spots in the field.
~Control: A 2-year rotation out of cucurbits is helpful. The varieties `Dasher
II', `Turbo', `Calypso', `Cross Country', `Flurry', `Royal', `Regal', `Quest',
`Cherokee', `Marketmore', and `Pioneer' are resistant to powdery mildew.
Usually the disease is not severe enough to warrant a spray program. Under
greenhouse conditions sulfur dust, Benlate, or wettable sulfur will control
the disease. CAUTION-- Sulfur can cause injury to cucumbers, especially when
temperature exceeds 85 F. Benlate may be used as a field spray.
Benlate Warning: Resistant strains of many fungus pathogens have become
troublesome when Benlate is used exclusively in a spray schedule. To reduce
the possibility of Benlate resistance, alternate Benlate sprays with sprays of
non-benzimitazole fungicides.
Field Spray -- Bayleton 50 WP or 50 DF. Apply 2 to 4 oz/A in a minimum of 10
gal of water by ground or 5 gal of water by air. Begin when disease first
appears and repeat at 14-day intervals. Do not apply more than 16 oz of
Bayleton 50 WP or 50 DF per season. Bayleton will not give control of
Sphaeroteca fuliginea.
Residues: Benlate--0.125 to .250 lb ai/A ground application only. Tolerance
1.0 ppm. Limitation 0.250 lb ai/A. No time limits.
---------------------------------------------------------------------------
CUCUMBER -- ROOT ROT
See Squash--Root Rot.
---------------------------------------------------------------------------
CUCUMBER -- SCAB
Cause: A fungus, Cladosporium cucumerinum, which overwinters in cucumber
debris, in cracks of greenhouses, and on the seed.
Symptoms: The fungus causes severe injury on the fruit, which can be infected
at all stages of growth, but which is particularly susceptible while young. At
first a sticky substance is exuded in drops as if the trouble were the result
of an insect puncture. Spots then gradually turn gray, become slightly sunken,
and enlarge to about inch in diameter. The canker gradually grows darker and
the tissue collapses further into the cucumber until a pronounced cavity is
formed, which is lined with a dark-green velvety layer of the fruiting fungus.
The first symptom on foliage is the appearance of a slightly water-soaked
paler-green area between the veins, as well as on them. These spots usually
are numerous. Gradually the spots turn gray to white and become angular. The
fine veinlets in the spots may remain brown or tan and are distinct against
the white background. The dead tissue cracks, breaking away until the whole
leaf has a ragged appearance.
The spores are disseminated by insects, clothing, tools, and are blown long
distances in moist air. Host penetration takes place in less than 9 hours
following germination and visible infection in 3 days. Spore production may
occur on the fourth day.
~Control: Use resistant varieties whenever available. Scab-resistant varieties
have been developed and include `Dasher II', `Raider', `Encore', `Sprint',
`Poinsett 76', `Turbo', `REgal', `Flurry', `Calypso', `Quest', `Gemini',
`Marketmore', `Pioneer', `SMR-58', and `SMR-18'. Commercial growers should
consult processors for the resistant varieties to be grown.
Spray -- 2 to 3 pt. of Bravo 720. Bravo may be applied through overhead
irrigation. See label for directions.
---------------------------------------------------------------------------
CUCUMBER -- SEED TREATMENT
Aids in control of seed decay and damping-off.
Thiram--0.75 of 50 percent material/lb of seed. Do not apply more than 2.25
oz actual/100 lb of seed (dry or slurry). Considered to be a nonfood use.
Captan .7 to 1.6 oz ai (slurry) or 1.5 to 2.25 oz ai (dry)/100 lb of seed.
Considered to be a nonfood use.
Apron FL 1.5 fl oz/cwt seed.
Anchor at 1.5 fl oz/cwt seed.
---------------------------------------------------------------------------
CUCUMBER -- WHITE MOLD
Cause: Sclerotinia sclerotiorum, a fungus.
White mold is a widespread but relatively unimportant disease of cucumbers
grown in the field, but it has caused severe losses of vines and fruit grown
in greenhouses.
Symptoms: This disease occurs primarily as a stem blight or as a fruit rot.
Older vines are most often affected. Following the development of the white
cottony mold, the stem dries and becomes withered, and the small sclerotia
appear in the rotting tissues. Cucumber fruits affected are watery, soft, and
later develop sclerotia.
~Control:
1. Rotate crops and deep plow to bury sclerotia.
2. Remove infected vines and fruit from the field and destroy.
______________________________________________________________________________
______________________________________________________________________________
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---------------------------------------------------
This information was adapted by the Oregon State
University Extension Service from Oregon and
Pacific NW publications as well as other vegetable
production guidelines from public institutions
in the U.S. and Canada. These guidelines are
intended as a general guide for Oregon commercial
vegetable producers. Address comments or questions
to your County Extension Agent or Dr. N. S.
Mansour, Department of Horticulture, Oregon State
University, Corvallis, OR 9733l.
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