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FAQ: Cabbages
CABBAGE
Brassica oleracea (Capitata Group)
VARIETIES (approximately 75 days for early varieties, 90 days for mid-season,
to over 120 days for late large-headed varieties).
A wide range of excellent cabbage varieties are available that are
resistant to heat, cold, and a number of important diseases and physiological
disorders. Choose test varieties carefully. The following is only a repre
sentative listing.
Fresh Market:
Early - Heads Up, Market Victor, Earliana, Stonehead, Princess, Golden
Acre. For Trial: Cheers, Green Cup (both Fusarium Yellows resistant and Black
Rot tolerant)
Mid-season - Applause, Bravo, Market Topper, Market Prize, Tastee,
Protector. For trial: Pacifica, Quisto. K-K cross and O-S Cross (heat
tolerant, large).
Late - Zerlina, S-D Cross, Excel, Bartolo, Winter Star, Danish Ballhead
strains, Houston Evergreen.
Savoy Cabbage: Savoy Ace.
Processing: Processor specifies varieties. The following have been
grown successfully: Bravo, King Cole, Sanibel, Roundup, Superette, Titan 90,
Danish Ballhead, Late Flat Dutch. For trial: Atria (very late); Carlton
(mid-season); Ergon (very late); Krautking (late, large); Krautpacker (mid-
season); Marvellon (early); Orbit (late); Rodolfo (mid-season); Sagitta
(late). Those for trial are suggested on the basis of New York data.
Red Cabbage: Ruby Perfection, Red Acre, Ruby, Ruby Ball, Red Head. For
Trial: Cardinal.
Note: Black Rot resistance is reported for the varieties Cheers, Green
Cup, Zerlina, Bravo, Genesis, Protector and the red types Ruby Perfection and
Red Head. Also, Rio Verde, Bravo, King Cole, Little Rock, Falcon, Titanic 90,
and Ruby Perfection (red) may be less susseptible to thrip injury (New York
data).
Overwintering Cabbage, for trial only: Green Glow, Spring Time, Spring
Hero, Spring Queen 2nd, F-S Cross. Varieties are listed by order of maturity.
Intended for planting in September for spring and early summer harvest
(approximately 220 days) in mild winter areas. Do not plant too early to
avoid bolting.
Ornamental Cabbages, also known as flowering kales: Sekito, Red Pigeon,
White Pigeon, Rose Bouquet, White Lady. These may be marketed as garnishes
for salad bars.
Novelty: Walking Stick Cabbage. Used to make walking sticks with
character! Thompson and Morgan Seed Co. provides seed and instructions.
SEED COMPANIES
Abbott & Cobb Inc. POB F307, Feasterville, PA 19047
Asgrow Seed Company, POB 5038, Salinas CA 93915
American Takii Inc., 301 Natividad Rd. Salinas, CA 93906
Bejo Seeds, 1323 E. Fir St. Mount Vernon WA 98273
Brinker Orsetti Seed Co., 2339 A Technology Parkway, Hollister CA 95023-2513.
408/636-4822
Daehnfeldt Inc. POB 947, Albany, OR 97321
Elsoms Seeds Ltd. Spalding, Lincolnshire, England PE11 1QG
Ferry-Morse Seed Co. POB 4938, 555 Codoni Ave. Modesto, CA 95352
Gleckler's Seedmen, Unusual Seed Specialties. Metamora OH 43540
Harris Moran Seed Co. 3670 Buffalo Rd. Rochester, NY 14624
Reed's Seeds, 3343 NYS Route 215, Cortland, NY 13045
Rogers NK Seed Co. PO Box 4727 Boise, ID 83711-4727
Nunhems Zaden, Canners Seed Corp. 221 E. Main St. Lewisville, ID 83431
Royal Sluis Inc. 1293 Harkins Rd. Salinas, CA 93901
Sakata Seed America Inc. P.O. Box 877, Morgan Hill, CA 97037
Stokes Seeds Inc. POB 548, Buffalo, NY 14240
Sunseeds Genetics, Inc. P O Box 1438, Hollister, CA 95023
Thompson and Morgan. POB 1308 Jackson, NJ 08527 ph: 201/363-2225
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
IMPORTANT
Before planting this Crucifer crop, consider the following important
factors:
1. No crucifer crop, or related weed has been present in the field for
at least 2 years, 4 years preferable. Crucifer crops include cabbage,
cauliflower, broccoli, kale, kohlrabi, Brussels sprouts, Chinese cabbage, all
mustards, turnips, rutabagas, radishes etc. Cruciferous weeds include wild
radish, wild mustards etc. Also, crucifer plant waste should not have been
dumped on these fields.
2. Soil pH should be 6.5 or higher. Soil pH over 6.8 is necessary to
manage club root. The application of 1500 lbs/acre of hydrated lime, 6 weeks
prior to planting is recommended for soils with pH less than 7.5 for club root
control (see Disease Control section for more details).
3. Arrange to keep transplanted and direct-seeded fields separate to
minimize spread of certain diseases that are more prevalent in transplanted
fields.
SOIL
Cabbage may be grown on a variety of soils but it does best on a well-
drained, loam soil well supplied with organic matter. Sandy loams are
preferred for early crops. Adjust soil pH to 6.0 - 6.8 for maximum yields.
SEED AND SEED-BED TREATMENTS
Cabbage seed numbers approximately 144,000 per pound. Pelletizing is
not necessary but primed and coated seed is becoming popular. Consult your
seed dealer about the availability of primed seed. Cabbage is most commonly
direct seeded. Some early production is transplanted.
Use certified, or hot-water treated seed and fungicide treat seed to
protect against several serious seed borne diseases. Hot water seed treat
ments are very specific (122 F exactly, for 25 to 30 minutes; the wet seed
must then be quickly cooled and dried). The seed treatments are best done by
the seed company, and can usually be provided upon request.
TRANSPLANT PRODUCTION
Seed Beds for transplants:
Locate these in an open, well drained area, free of club-root. Lime if
necessary, and fertilize with 10-30-10 at 625 lb/acre or its equivalent.
When seedlings are to be grown in a seed-bed for production of trans
plants, choose a site where cole crops have not been grown before, or fumigate
prior to seeding with an approved fumigant following lable and manufacturer's
recommendations.
Always use certified or hot water treated seed for transplant produc
tion. Seed in a greenhouse for an early crop, in a cold frame for a less
early crop, and in outdoor seed-beds when the weather is warm enough for
germination and growth (above 50 F). In each case seed 5-6 weeks ahead of
when the plants are wanted for transplanting.
Four to 6 ounces of high quality, sized and density graded seed will
provide enough transplants to plant 1 acre. In the seed-bed use a drill with
a scatter shoe to drop 15 to 20 seeds per foot in rows 10 inches apart.
Greenhouse transplant production
Precision seed into modular flats, styrofoam trays or blocks of a peat-
lite (peat vermiculite) mix or other suitable growing medium. Crowding should
be avoided. Provide 1.5-2.5 square inches per plant in modular trays.
Temperatures should be maintained above 45 F at night and below 85 F
during the day. Seven days before transplanting start the hardening off
process.
Follow the same process in a cold frame, or seed directly into the
covered soil after it has been limed, fertilized and fumigated as for outdoor
seed-beds.
FIELD SEEDING
In western Oregon fresh market cabbage may be field seeded from mid
March to August 10. Cabbage for processing is generally seeded from mid April
to the end of July.
Preparation for direct seeding needs the same attention a seed-bed area
would be given A fine-textured soil, free of rocks, clods and trash, firm and
very level, is required for precision seeding.
Use a precision seeder such as a Stanhay, or Gaspardo vacuum planter, to
drop 2 seeds 2 inches apart every 15 inches. After the first true leaves have
formed, thin to one plant per location. In continuous seeding, thin the
plants so as to leave 15 to 18 inches between them.
SOIL
Cabbage may be grown on a variety of soils but it does best on a well-
drained, loam soil well supplied with organic matter. Sandy loams are
preferred for early crops. Adjust soil pH to 6.5 - 7.0 for maximum yields.
FERTILIZER
A soil test is the most accurate guide to fertilizer requirements. The
following recommendations are general guidelines for western Oregon:
Good management practices are essential if optimum fertilizer responses
are to be realized in the production of cabbage. These practices include use
of recommended varieties, selection of adapted soils, weed control, disease
and insect control, good seedbed preparation, proper seeding methods, and
timely harvest.
Because of the influence of soil type, climatic conditions, and other
cultural practices, crop responses from fertilizer may not always be accu
rately predicted. Soil test results, field experience, and knowledge of
specific crop requirements help determine the nutrients needed and the rate of
application.
The fertilizer application for cabbage should insure adequate levels of
all nutrients. Optimum fertilization is intended to produce top quality and
yields in keeping with maximum returns.
The suggested fertilizer applications are based on a 36" row spacing.
With decreased row spacings, increased fertilizer rates are suggested.
Recommended soil sampling procedures should be followed in order to
estimate fertilizer needs. The Oregon State University Extension Service
agent in your county can provide you with soil sampling instructions, soil
sample bags, and information sheets.
Where cabbage is direst seeded, see "field fertilization section below.
If transplants are to be used, and if transplants are to be field grown,
fertilize transplant productions beds as follows:
TRANSPLANT BED FERTILIZATION
Broadcast and work into the transplant bed:
1. 40 to 70 lbs Nitrogen/A.
2. Apply phosphorus, potassium, sulfur, magnesium, boron, molybdenum,
and lime up to the maximum rates suggested below for field applications.
TRANSPLANTING SOLUTIONS
Dilute solutions of complete fertilizers high in phosphorus promote
quick recovery and early growth of transplants. One-half pint of trans
planting solution should be injected into the furrow at the roots of each
plant at time of transplanting. A transplanting solution may be prepared by
dissolving 3 lbs. of 11-48-0 or similar monoammonium phosphate fertilizer in
a 55 gallon drum of water.
FIELD FERTILIZATION
NITROGEN (N):
A total application of 80-100 lbs. N/A is suggested.
Broadcast about half of the N just prior to direct seeding or trans
planting or band 60-90 lbs N/A with the phosphorus. Broadcast the remaining
nitrogen at the time of last cultivation, or 1 to 2 weeks before the first
cutting. At the higher rates, two applications should be made 2 to 3 weeks
apart.
Nitrogen liquid fertilizer formulations having herbicidal effects:
AN-20, Ammonium Thiosulfate and mixtures of these two materials can be
used successfully in a number of Brassica crops such as broccoli, cabbage, and
cauliflower. The amount of nitrogen per gallon of material, the rate at which
it is applied, and the phyto-toxicity of the material determines what crops
these can be used on.
All of these materials, when applied at the proper time and manner have
the added benefit of ancillary control of many small (less than 3 inches)
broadleaf weeds such as groundsell, pineapple weed, shepherdspurse, mallow,
pigweed, hairy nightshade chickweed and many others. Poor, or no control is
obtained on lambs quarters, purslane, henbit, black nightshade, knotweed, sow
thistle, malva goosefoot and grasses.
When using these nitrogen sources in foliar applications, follow cau
tions listed. Severe crop injury may occur if cautions are not observed.
General cautions for the use of nitrogen liquid fertilizer formulations
are:
* Apply only after the crop has at least two true leaves. Application
at between the 3rd and 6th true leaf stages is least likely to cause crop
injury.
* Do not apply within 4 days of a period of cool, cloudy or rainy
weather, or if free water is present on the leaves.
* Discontinue application if spray droplets do not roll off or "bead-
up" on the leaves. This indicates a deficiency of adequate waxy cuticle, and
may be a temporary condition due to rapid growth, cloudy or rainy weather, or
more seriously, the lack of adaptability of the variety.
* Do not apply within 4 days after a foliar pesticide has been applied,
or with any wetting agent.
* Use large nozzles to minimize misting and possible injury to the crop
growing point.
* Direct the spray to the base of the crop with wide, low nozzles, or
use crop shields whenever this can be done while still obtaining complete
coverage of the weeds.
AN-20 fertilizer formulation:
This is a manufactured 20-0-0 formulation (containing 20% N) that may be
applied at 50 to 70 gallons of product per acre as a foliar spray. This
formulation weighs 10.55 lbs per gallon and contains 2.11 lbs N/gallon of
product and would provide approximately 100 to 140 lbs N/acre (but some N is
lost through volatilization). Do not irrigate for 48 hours after application,
but irrigate then to move the fertilizer into the root zone.
When this treatment is used, subsequent nitrogen side dressings may be
reduced by a portion of the amount of N applied in the treatment.
Note: Mixtures of An-20 and Ammonium thiosulfate (usually 1:1) can be
made which will reduce the amount of nitrogen applied, provide some sulfur (if
AN-20 only would have been applied, and reducing the sulfur if only Ammonium
thiosulfate were to be used), and be as effective as either material alone.
Application rates are still held at 50 to 70 gallons of the mixture per acre.
Note: This formulation is different from a solution that could be
prepared by dissolving ammonium nitrate in water. Such a solution would not
have the same concentration or herbicidal effect.
Also, To prevent crop injury, follow the cautions listed above.
*****
Ammonium thiosulfate:
This is a manufactured 12-0-0-26 formulation (containing 12% N and 26%
sulfur) and weighs 9.33 lbs per gallon. It may be applied at 50 to 70 gallons
of product per acre as a foliar spray. This solution contains 1.12 lbs
nitrogen and 2.4 lbs sulfur per gallon of product and would provide approxi
mately 55 to 75 lbs N/acre (some N may be lost through volatilization). At
the application gallonage mentioned, about 150 to 168 lbs of S are also
applied. Do not irrigate for 48 hours after application, but irrigate then to
move the fertilizer into the root zone.
When this treatment is used, subsequent nitrogen side dressings may be
reduced by a portion of the amount of N applied in the treatment.
Note: Mixtures of An-20 and Ammonium thiosulfate (usually 1:1) can be
made which will reduce the amount of nitrogen applied, provide some sulfur (if
AN-20 only would have been applied, and reducing the sulfur if only Ammonium
thiosulfate were to be used), and be as effective as either material alone.
Application rates are still held at 50 to 70 gallons of the mixture per acre.
Also, To prevent crop injury, follow the cautions listed above.
*****
PHOSPHORUS (P):
Phosphorus fertilizer should be banded at the time of seeding or trans
planting. Bands should be located 2-3" to the side of the seeds or plants and
3-4" deep.
If the OSU soil test Apply this amount of
for P reads (ppm): phosphate (P2 O5) (lb/A):
0 - 30 150 - 200
30 - 50 100 - 150
Over 25 80 - 100
POTASSIUM (K):
Limit band applications of K to 90 lbs K2 O/A. Broadcast remainder of K
and work into seedbed prior to planting. The total of N plus K2 O in the band
should not exceed 90 lbs./A. Apply K as follows:
If the OSU soil test Apply this amount of
for K reads (ppm): potash (K2 O lb/A):
0 - 150 150 - 200
150 - 200 90 - 150
200 - 250 60 - 90
Over 250 None
SULFUR (S):
Include 25-40 lbs/A of S in the fertilizer pro gram. 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 S
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 conversion 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 acidify
ing effect on soil.
The S requirements of crucifers can be provided by:
1. The application of 25-40 lbs S/A in the form of sulfate at or prior
to seeding or planting.
2. Applying 40-50 lbs S/A as fine ground (finer than 40 mesh) elemental
S the preceding year.
3. Applying coarser ground elemental S at higher rates and less fre
quently.
MAGNESIUM (Mg):
When the OSU soil test value for Mg is below 2 meq/100g soil, band 15-
20 lbs Mg/A at transplanting or seeding time. If Mg deficiency symptoms
develop, spray with 10 lbs of Epsom salts in 100 gals of water/A.
Magnesium can also be supplied in dolomite, which is a liming material
and reduces soil acidity to about the same degree as ground limestone.
Dolomite should be mixed into the seedbed at least several weeks in advance of
seeding and preferably the preceding year. It can also be supplied by the
application of Epsom salts or Sul-Po-Mag fertilizer prior to seeding or
transplanting as follows:
* Sul-Po-Mag at 150 to 200 lb./acre.
* OR Epsom salts at 150 to 200 lb./acre.
* OR Dolomitic Limestone at 225 to 275 lb./acre.
BORON (B):
Cabbage is sensitive to boron deficiency. Apply boron as follows:
If the OSU soil test Apply this amount
for B reads (ppm): of B (lbs/A):
0 - 1 3 - 4 broadcast
1 - 3 1 - 2 broadcast
Over 3 1/2 - 1 foliar spray
A satisfactory foliar spray contains 1 lb B/100 gals of water.
Fertilizers containing B should not be banded.
Fields East of the Cascades or where winter rainfall is low, and to
which the higher rates of boron has been applied should not normally be
planted to beans or cucumbers the following year, as both these crops are
extremely sensitive to boron.
LIME:
If a mineral soil is below pH 6.3 or an organic soil is below 5.5 and/or
the calcium (Ca) level is below 8 meq/100g soil lime should be applied.
Compared to other vegetables cabbage has a fairly high lime requirement.
The application of lime is suggested when the soil pH is below 6.3
If the OSU SMP Buffer Apply this amount
test for lime reads: of lime (T/A):
Below 5.6 5 - 7
5.7 - 5.9 4 - 5
5.9 - 6.1 3 - 4
6.1 - 6.3 2 - 3
6.3 - 6.6 1 - 2
Over 6.6 None
The liming rate is based on 100-score lime.
Lime should be mixed into the seedbed at least several weeks before
seeding and preferably the preceding year. A lime application is effective
over several years.
Some soils may have a fairly high OSU SMP buffer value (over 6.6) and a
low pH (below 6.0). This condition can be caused by the ap plication 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 nitrogen fertilizer materials. Acidifying
fertilizers also have a long term acidifying effect on soil which is cumula
tive 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 lime (1 to 2 ton/A) should suffice to neutralize soil acidity.
For acid soils low in Mg (less than 0.5 meq Mg/100g soil) one T/A of
dolomite lime can be used as a Mg source. Dolomite and ground limestone have
about the same ability to neutralize soil acidity.
The P, K, Mg, B and lime recommendations are based on soil test values
from the Soil Testing Laboratory, OSU, Corvallis, Oregon.
These recommendations are largely based on the results of experiments
conducted by Oregon State University Agricultural Experiment Station Hort
iculture and Soils Department research faculty.
These recommendations are quoted from OSU Fertilizer Guide FG 27.
IRRIGATION
In soil suspected of having club root, care should be taken in not
over-watering transplants after setting them out. A total of 10-14" of water
may be needed for direct seeded fields and 10-12" for transplanted ones in
western Oregon. Approximate summer irrigation needs for the Hermiston area
have been found to be: 3.5 inches in May, 5.0 in June, 7.5 in July, and 7.0 in
August.
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, HANDLING AND STORAGE
In western Oregon fresh market cabbage may be harvested from mid July to
the end of December. The main harvest period is between the first of August
and mid November.
Cabbage for processing is generally harvested from about mid July to mid
November.
Average yields of processed cabbage in the Pacific Northwest are
approximately 30 tons/acre with good yields about 40 tons/acre. Average fresh
market yield is reported at 235 cwt./acre with good yields about 300 cwt./a
cre.
Processed cabbage can be machine harvested, but is ususally hand
harvested in the Pacific Northwest. All fresh market cabbage is hand harves
ted. Heads should be harvested when firm and before they split or burst. In
harvesting for fresh market, leave 4-6 wrapper leaves attached to the head.
The wrapper leaves are usually removed when harvesting for kraut.
STORAGE (Quoted from USDA Ag. Handbook #66):
Store cabbage at 32 F. and a relative humidity of 98 to 100%. A large
percentage of the late crop of cabbage is stored and sold during the winter
and early spring, or until the new crop from the southern states appears on
the market. If stored under proper conditions late cabbage should keep for 5
to 6 months. The longest keeping cultivars belong to the Danish class.
Early-crop cabbage, especially southern grown, has a storage life of 3 to 6
weeks.
Cabbage is successfully held in common storage in the northern states,
where a fairly uniform inside air temperature of 32 to 35 F. can be maintai
ned. Many such storage houses are to be found, principally in New York,
Pennsylvania, Michigan and Wisconsin.
Storage houses should be insulated sufficiently to prevent freezing of
the cabbage; for although slight freezing does little harm, hard freezing may
cause considerable loss. Heaters are sometimes needed to prevent freezing of
cabbage in common storage during severe cold weather.
Cabbage wilts quickly if held under too dry storage conditions; hence,
the humidity should be high enough to keep the leaves fresh and turgid. Use
of polyethylene liners or pallet covers to prevent desiccation can prove
desirable under some storage conditions. Cabbage stored at 32 F. has less
decay when the relative humidity is maintained at or near saturation (98 to
100 %) than at 90 to 95 %.
Many growers now use pallet boxes as both field and storage containers
so that there is no handling of the cabbage from the time of harvest until
preparation for shipment or processing. Some of the larger storages stack
these pallet boxes five high.
An increasing quantity of cabbage is now held in mechanically refrige
rated storages. The storage life of late cabbage can be extended for several
months if it is held in an atmosphere with 2.5 to 5 % oxygen and 2.5 to 5 %
carbon dioxide. Cabbage should be handled carefully from field to storage,
and only solid heads with no yellowing , decay, or mechanical injuries should
be stored. Before the heads are stored, all loose leaves should be trimmed
away; only three to six tight wrapper leaves should be left on the head.
left on the head. Loose leaves interfere with ventilation between heads, and
ventilation is essential for successful storage. Upon removal from storage,
the heads should be trimmed again to remove loose and damaged leaves. Cabbage
should not be stored with fruits emitting ethylene. Concentrations of 10 to
100 ppm of ethylene cause leaf abscission and loss of green color within 5
weeks.
The most common decays found in stored cabbage are watery soft rot,
bacterial soft rot, gray mold rot, alternaria leaf spot, and black leaf speck.
PACKAGING
Containers and weights commonly used for cabbage are crates (l 3/4
bushels) 53-60 pounds, 50 pound mesh sacks, or 53 pound cartons.
PEST CONTROL FOR CABBAGE
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
Cultivate as often as necessary when weeds are small. Proper cultiva
tion, field selection and rotations can reduce or eliminate the need for
chemical weed control.
THE WEED TREATMENTS LISTED BELOW ARE TAKEN FROM THE PACIFIC NORTHWEST
WEED CONTROL HANDBOOK, AND ARE FOR INFORMATION ONLY. CONSULT PRODUCT LABELS
FOR CURRENTLY LEGAL REGISTRATIONS, RATES, AND COMPLETE INSTRUCTIONS.
WEED MANAGEMENT GENERAL STRATEGY
Weed suppression in crucifers begins by rotating crops that involve different
weed control practices or herbicides to disrupt weed life cycles. Row
spacings and plant densities vary to achieve head size depending on the
market and to suppress weeds. Early season weed control comprises application
of an herbicide and/or cultivation(s).
______________________________________________________________________________
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
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 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 preemergence 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.)
------------------------------------------------------------------------
glyphosate Consult Labels
Roundup
Roundup RT
(E. Washington and
Idaho only)
or Honcho +
nonionic surfactant
Apply to actively growing weeds either preplant in conjunction with site
preparatioon or preemergence crops listed on the label. Consult label
for specific rates, times of application, and perennial species control-
led. Generally 1 to 1.5 lbs ai/A should be used for annual weeds, while
perennial weeds require higher rates. Addition of a surfactant or
ammonium sulfate improves activity when weeds are stressed. Do not
apply more than 8 lbs. ai/A per year, nor plant non-labeled crops within
12 months following application. (Inhibits production of 3 amino
acids and protein synthesis.)
______________________________________________________________________________
PREPLANT INCORPORATED
Direct Seeded or Transplanted
Weed Treatment Active Ingredient Per Acre or Application Comments
------------------------------------------------------------------------------
trifluralin 0.5 to 1.0 lb ai/A
Treflan
Apply before planting and incorporate 2 to 3 inches deep by cross-disk
ing or using a PTO rotary tiller. Do not exceed 0.75 lb ai/A for direct
seeded crops. Spray only once and avoid overlapping. Consult label
for planting sensitive crops within 12 months. (Inhibits mitosis,
primarily in shoots).
______________________________________________________________________________
PREEMERGENCE
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
napropamide 1 to 2 lb ai/A
Devrinol
Selectivity is based on Devrinol placement above the seed or transplant
depth. For direct seeded crops, apply to soil surface immediately after
planting and sprinker irrigate within 24 hours to wet soil 1 to 2 inches
deep, or mechanically incorporate not exceeding the seed depth.
Transplants can be treated preplant with shallow incorporation or
postplant with sprinkler irrigation. Rotational crops listed on the
label require deep moldboard plowing while other crops should not be
planted sooner than 12 months following application. (Inhibits root
growth).
------------------------------------------------------------------------
DCPA 4.5 to 9 lb ai/A
Dacthal
Performs erratically west of Cascades. Elsewhere, apply immediately
after seeding or transplanting. Results can be improved if rainfall or
overhead irrigation occurs immediately after application. Consult label
for planting sensitive crops within 8 months. (Inhibits mitosis).
------------------------------------------------------------------------
oxyfluorfen 0.25 to 0.5 lb. ai/A
Goal
(transplanted broccoli,
cabbage, and cauliflower)
Apply soon after final soil preparation and before transplanting through
the treated layer with minimal soil disturbance. Select the lower rate
for coarse textured soils with less than 1% organic matter. Temporary
injury may occur when leaves contact treated soil. Severe injury may
result when transplants are under stress due to temperature, disease,
fertilizer salts, nematodes, insects, pesticides, and storage conditions
or when small transplants grown in 1 inch cells are planted. Following
transplanting, apply at least 0.25 inches overhead moisture. Plant only
crops listed on the label within 10 months following treatment. Grazing
of crop residue or treated fields is prohibited. (Acts as a selective
contact that disrupts cell membranes.)
______________________________________________________________________________
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 30 days of harvest,
nor exceed 3 pints/A per season. (Inhibits fatty acid production, cell
membranes, and new growth.
______________________________________________________________________________
______________________________________________________________________________
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 Monitor - 0.5 to 1 lb
Cabbage aphid
Brevicoryne brassicae malathion - 1.25 lb
Turnip aphid
Hyadaphis erysimi Phosdrin - 0.25 lb
Green peach aphid
Myzus persicae Dibrom - 1 to 2 lb
Both species gray, mealy plant diazinon - 0.5 lb
lice forming colonies on foliage,
on or in heads or in buds. Weak- Metasystox-R - 0.375 to 0.75 lb
en plants and constitute an
adulterant in processed foods. endosulfan - 0.75 to 1.0 lb
For effective aphid control, Di-Syston - 1 lb
application of insecticides
should start with first appearance Apply granules as a band on
of aphids and be continued at reg- each side of seed furrow or
ular intervals as aphids appear. transplanted row at planting,
This is particularly true of or as a side dressing after
broccoli and cauliflower to prevent plants become established.
aphids from concealing themselves
in heads. Liquid injections can be made
in similar manner. Do not apply
NOTE: directly to seed. See label for
To be effective Di-Syston application complete details.
should be followed by sprinkler or
furrow irrigation. Di-Syston is dimethoate - 0.25 to 0.5 lb
relatively insoluble and requires
high soil moisture to give best results. Lorsban 50W - 1 lb
Pyrellin - 1 to 2 pt
Diatect - 1 to 3 lb formulation
---------------------------------------------------------------------------
Cabbage maggot Transplantings
Delia brassicae diazinon - 0.125 to 0.25 lb/50
gal of water
White maggots that feed on
roots and underground stems Preplant and transplant
and weaken, lodge, and kill Lorsban 4E - 0.05 to 0.086 lb
plants. Adult is a small gray fly ai/1000 row ft.
that lays white, oblong eggs at
plant bases. Preplant
Lorsban 15G - 0.04 to 0.09 lb
diazinon - 2 to 3 lb
---------------------------------------------------------------------------
Cutworms and Asana - 0.03 to 0.05 lb
Armyworms
endosulfan - 1 lb
Several species. Do not feed treated plants.
Treat when worms are small.
carbaryl - 1 to 2 lb
permethrin - 0.05 to 0.2 lb
Bacillus thuringiensis - 1
to 2 qt. Add an appropriate
spreader-sticker to enhance
control. Most effective on
small larvae.
Lorsban 50W - 1 lb
Larvin - 0.4 to 0.8 lb
---------------------------------------------------------------------------
Diamondback moth endosulfan - 1 lb
Plutella maculipennis
diazinon - 0.5 lb
Small, pale yellowish-green larvae
with erect black hairs. Eats holes
in foliage. Adults are small gray
or grown moths with white marks on
forewings that form a diamond when
wings are folded.
---------------------------------------------------------------------------
Flea beetles endosulfan - 0.75 to 1.0 lb
including
cabbage flea beetle carbaryl - 1 lb
Phyllotreta cruciferae
methoxychlor - 2.25 lb
Small, shiny, steel-blue, jump-
ing beetle. Eats round holes in Di-Syston - 1 lb
leaves of wild and cultivated
crucifers. Particularly serious permethrin 0.05 to 0.2 lb
on seedlings.
Asana - 0.03 to 0.05 lb
NOTE: Carbaryl and endosulfan
combined together have given most Lorsban 50W - 1 lb
effective control.
Larvin - 0.4 to 0.8 lb
Pyrellin - 1.5 to 2 pt
---------------------------------------------------------------------------
Garden symphylan Dyfonate - 2 lb
Scutigerella immaculata
diazinon - 10 lb
Small, white, centipede-like an-
imals in the soil. Telone II - preplant
Telone C-17 - preplant
Mocap - 2 to 3 lb.
---------------------------------------------------------------------------
Grasshoppers Asana - 0.03 to 0.05 lb
Various species
Nosema locustae - Use as
May reach damaging levels on field manufacturer directs
margins during years of grasshopper
abundance.
---------------------------------------------------------------------------
Imported cabbage worm Phosdrin - 0.5 lb (ICW only)
Pieris rapae OR, (depending on pre-harvest
interval - see label)
Phosdrin - 1 lb (ICW only)
Caterpillars are soft, velvety
green with faint yellow stripes. Larvin - 0.6 to 1 lb
Adult is a white butterfly with
black spots. diatect - 1 to 3 lb
Monitor - 0.5 to 1 lb
Lannate - 0.45 to 0.9 lb
Bacillus thuringiensis -
1 to 2 qt. Add appropri-
ate spreader-sticker.
Dibrom - 1 to 2 lb
methoxychlor - 2 to 2.25 lb
Asana - 0.03 to 0.05 lb
permethrin - 0.05 to 0.1 lb
Lorsban 50W - 1 lb
Larvan - 0.4 to 0.8 lb
Pyrellin - 1 to 2 pt
---------------------------------------------------------------------------
Loopers, including Monitor - 0.5 to 1.0 lb
Cabbage looper
Trichoplusia ni WARNING: If methamidophos
(Monitor) is allowed to drift
Alfalfa looper onto adjacent legume or vege-
Autographa californica table seed crops, it is highly
hazardous to pollinating bees.
Larvae of both species pale Alternate materials should be
green with white lines on back used under such conditions.
and sides. Move in looping
manner. Moth gray-brown with Lannate - 0.45 to 0.9 lb
characteristic silvery spot on
forewings. Bacillus thuringiensis - 1 to 2
qt. Add a spreader-sticker to
NOTE: enhance persistence on foliage.
The cabbage looper and alfalfa looper Dibrom - 2 lb
are not serious pests every year but
are more difficult to control than methoxychlor - 2.25 lb
other cabbage "worms". Start insecti-
cide applications when the worms are endosulfan - 0.75 to 1.0 lb
still small. Inspect the plants a day
or so after each treatment for success permethrin - 0.05 to 0.2 lb
of control. Examine plants often in
late summer and fall for new infestations. Asana - 0.03 to 0.05 lb
Be sure insecticides reach both sides of
leaves. Choice of insecticide is de- Phosdrin - 0.5 lb
pendent in part on nearness to harvest.
Phosdrin gives better control of loppers carbaryl - 2 lb
when temperatures are below 70 F.
pyrellin - 1 to 2 pt
NOTE:
Larvin - 0.6 to 1 lb
Suitable registered wetting agents should
be added to most of the spray solutions of diatect - 1 to 3 lb
the mentioned insecticides. The wetting
agent will aid in spreading and sticking
of the sprays to the waxy leaves and
plant surfaces.
---------------------------------------------------------------------------
Slugs metaldehyde baits
---------------------------------------------------------------------------
Thrips methyl parathion - 0.3 to
Frankliniella sp. 1.5 lb
Adults about 1/25 inch in length. Yellow-
ish to black in color. An occasional problem
in fresh market cabbage.
---------------------------------------------------------------------------
Wireworms diazinon - 3 to 4 lb active
Ctenicera and ingredient per acre. Broadcast
Limonius spp. granules or emulsifiable formu-
lation evenly on the soil
Brown, jointed larvae of click surface and incorporate into
beetles. the top 4-8 inches of soil.
Other controls and fumigants
may be available.
Telone II or C-17 - preplant
___________________________________________________________________________
___________________________________________________________________________
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.
CABBAGE -- BLACK BLIGHT (RING SPOT) IN SEED PRODUCTION
Cause: Mycosphaerella brassicicola, a fungus that attacks cabbage,
cauliflower, brussels sprouts and broccoli.
Symptoms: Individual spots most often are black with dense fruiting bodies in
tight concentric rings. Under severe attack, the spots coalesce and the entire
plant may be affected and blackened. When seed stalks are attacked, the fungus
causes distortion similar to 2,4-D symptoms. The infectious spore stage
matures slowly over a period of months.
Control:
1. Locate plant beds 1 mile or more from diseased fields.
2. Burn straw stacks and plow under diseased refuse of cabbage, turnip, and
rutabaga seed fields immediately after harvest and before transplanting the
new crop.
3. Hot water seed treatment at 122oF for 30 minutes eliminates seedborne
inoculum.
4. Bravo and Benlate provide control of this disease when applied for downy
mildew and white blight, respectively.
5. Bravo may be applied to cabbage, broccoli, and brussels sprouts.
---------------------------------------------------------------------------
CABBAGE -- BACTERIAL SOFT ROT
Cause: Erwinia sp., a bacteria. Entrance to the plant tissue is usually
through wounds caused by insects, disease organisms, or mechanical means.
Under warm, humid conditions, uninjured tissue may become infected. The
bacteria may be spread by insects, tools, rain, clothing, or affected plant
tissue.
Symptoms: Small, water-soaked areas which rapidly increase in size. The
tissue becomes soft and mushy, and within a few days the affected plant part
may collapse. An offensive odor is usually present.
Control:
1. Set out plants in rows to allow for good air drainage.
2. Use care in cultivating to keep injuries to leaves and other parts
ofplants to a minimum.
3. Overhead irrigation may encourage infection. Well water contains less
bacteria than surface water.
4. Clean and spray storage walls and floors with copper sulfate solution (1
lb/5 gal water). Bactericides such as Roccal, Chlorox, and Lysol are also
effective.
5. In storage, use a buffering material such as straw, paper, etc., to
prevent injury to the heads.
6. Keep storage house dry and the temperature below 39 F.
---------------------------------------------------------------------------
CABBAGE -- BLACK LEG
Cause: Phoma lingam (Leptosphaeria maculans), a fungus which is carried on the
seed and overwinters on plant debris and on alternate host plants.
Symptoms: Pale spots on leaves, stems, and silques (pods) which later become
ashy gray with scattered black pycnidia on the surface. Stem lesions near the
soil line extend below the soil surface causing a black rot of the lower stem
and roots. As plants mature they fall sideways from lack of root anchorage.
Many plants wilt and die.
Seed crop symptoms: This disease generally does not cause reduction in seed
yields. Occasionally cankers are observed on stem bases and spots appear on
overwintered leaves. Symptoms on seed pods are rare and inconspicuous. Low
levels of seed infection coupled with weather favorable for disease spread in
eastern seedbeds has caused extremely severe losses.
Control--Seed Production Fields
1. Plant only stock seed assayed and found to be free of P. lingam. Treat
infected stock seed with benomyl as Benlate at 8 oz 50 WP plus thiram as
Arasan at 8 oz 50 WP (Washington and Oregon only) or hot water treated at 50 C
for 25 to 30 minutes. Treated stock seed should be reassayed and found free
from infection before planting.
2. Seedbeds should not have crucifer crops on or near them for at least 5
years.
3. Inspect seedbeds for obvious foliar infections.
4. When lifted, transplants should not be dipped into water before transplan
ting.
5. Inspect seed fields for presence of the disease.
6. Seed samples (10,000 seeds) from each lot should be assayed for the
presence of P. lingam.
7. Treat infected lots with benomyl as Benlate and thiram as Arasan (see
above) or hot water. Seed assays are available from the Washington State
University Seed Technology Laboratory, Pullman, Washington.
Control--Crop Fields:
Use disease-free seed.
---------------------------------------------------------------------------
CABBAGE -- BLACK ROT
Cause: Xanthomonas campestris pv. campestris, a bacterium which overwinters in
plant refuse and is carried internally and externally on seed.
Symptoms: When spread by water, bacteria enter water pores at the margins of
leaves or occasionally through insect or other mechanical injuries. The tissue
in these areas becomes yellow and the chlorosis progresses toward the center
of the leaf. This creates a V-shaped area with the base of the V at the midrib
of the leaf. The veins in these areas become dark brown or black, and when the
leaf is held up to a strong light source they show up as a black net. From the
leaf, the infection proceeds up and down the main stem causing blackening of
the vascular tissue. The infection goes systemic at this point, and symptoms
the same as those found from direct infection may appear anywhere on the
plant. Unilateral stunting of some leaves occurs.
When seed is infected, the first symptoms appear on the cotyledons. The
cotyledons rapidly wilt and drop off usually however, the infection has
reached the stem and proceeds upward. Development of the disease may stop in
unfavorable weather only to begin when conditions are favorable. Optimum
temperatures for development are 80o to 86o F. Water in the form of dew, rain,
or sprinkler irrigation is necessary for spread.
Control:
1. Use clean seed. Seed from west coast sources is almost always free from
this disease.
2. Use a 2-year rotation out of crucifers in production fields.
3. Use a 3-year rotation on the transplant bed. This is most important since
most infection spread occurs in the seed bed.
4. Contaminated seed can be cleaned by hot water seed treatment of 122 F for
30 minutes.
5. The varieties `Defender' and `Guardian' are resistant. Other research
from N.Y. classifies varieties in regards to their susceptibility as follows:
Susceptibility to Black Rot
Low Medium High
Bravo Green Winter Superdane
Hinova Superelite Superkraut
Zerlina Atria Titanic 90
Renova Protector Roundup
Stonar Krautking King Cole
Little Rock Krautpacker
Rodolfo
Bartolo
Polinius
Lennox
---------------------------------------------------------------------------
CABBAGE -- CLUB ROOT
Cause: Plasmodiophora brassicae, a fungus. This fungus can survive in the soil
for years following an infected crop.
Symptoms: Young plants wilt in hot weather, but recover partially at night.
Older plants are stunted, and leaves may drop off. Roots develop clubs or
swellings up to 5 or 6 inches in diameter. The largest clubs are usually just
below the soil level, on the larger roots.
Control:
A. The cabbage variety `Badger Shipper' offers resistance to some races of the
disease.
B. Disease-free plants and disease-free soil:
Since young plants can be infected and not show any symptoms, e.g., swelling
of the roots, it is important that only plants grown in soil known to be free
of the casual fungus be planted. If possible, plant only in club-root-free
soils, but when in doubt, it is better to treat.
C. Disease-free plants and diseased soil:
If it is not possible to use disease-free soil, the following practices and
chemicals will aid in keeping club root under control.
1. Lime field heavily, which discourages spore germination. Even if the
infected soil is alkaline, e.g., has a pH 8, at least 1500 lb of hydrated lime
must be added to the soil each time cabbage is planted. Use long rotations to
prevent a buildup of lime in the soil. The hydrated lime should be added to
the soil at least 6 weeks before planting.
2. Preplanting soil treatment with PCNB (Terraclor). PCNB does not give
complete control of club root, but it will reduce the number of clubs and
secondary rotting of roots so that a nearly normal sized crop may be produced.
Broadcast: For transplant or direct-seeded fields, use 40 lb actual PCNB/A,
depending on soil type. Disc or rototill the PCNB into the top 4 inches of
soil.
The treatment is effective for two seasons if the soil is only rototilled and
cultivated, not plowed.
Bands: For transplant or direct-seeded fields. Although a savings in chemical
may be made the first year by applying it in bands previous to planting and
cultivating it into the top 4 inches of soil, the second year benefit from
this application of chemical is lost.
3. Use starter solutions (use at rate of 1 cup/plant at time of planting).
a. PCNB (Terraclor) .5 to .75 percent suspension (4 lb of 75 percent WP/100
gal water). This treatment is recommended only for commercial growers.
4. Delay planting to avoid wet soil.
Residues: Terraclor--cabbage: Tolerance 0.1 ppm (Interim).
Row application prior to transplanting (maximum 40 lb actual PCNB/A).
Broadcast prior to planting (maximum of 40 lb actual PCNB/A).
Transplant solution--.75 pt/plant of transplant solution containing 4.5 lb
actual PCNB/100 gal.
---------------------------------------------------------------------------
CABBAGE -- DAMPING-OFF AND WIRESTEM
Cause: Several fungi including Rhizoctonia and Pythium sp. These fungi are
common soil inhabitants. They are widespread and can be very destructive under
cool, moist conditions.
Symptoms: Damping off results in killing of seedlings before or soon after
they emerge from the soil. Beneath the soil a general rot is observed.
Seedlings which emerge from the soil develop a lesion near where the tender
stem is in contact with the soil surface, and the seedling collapses. In some
cases, the seedling may continue to grow even though the lesion has girdled
the stem. The lesion is quite sunken, and the stem resembles a wire, hence the
name wirestem. The girdled seedling eventually dies.
Control:
1. Delay planting as long as possible to avoid cold, moist soils, which favor
disease development.
2. Avoid excessive irrigation. Irrigate in the morning.
3. Grow transplanted seedlings in sterilized soil.
4. Improve the texture of heavy soils.
5. See Cabbage -- Treatment.
6. When Pythium spp. is a problem, apply Ridomil 2E.
Broadcast: Apply 4 pt Ridomil 2E/A at planting in 20 to 50 gal water.
Banded: Apply 0.5 to 1 pt Ridomil 2E/13,000 linear ft of row in a 7-inch band.
Broadcast and incorporated: Apply 1 to 2 pt/A as a broadcast soil application
in 20 to 50 gal of water and incorporate in the top 2 inches of soil. If
plantings are made on bed, broadcast and incorporate before forming beds. To
minimize the development of fungi resistant to Ridomil, do not make foliar
applications if Ridomil was used at planting (see Cabbage and Cauliflower --
Downey Mildew).
---------------------------------------------------------------------------
CABBAGE -- DOWNY MILDEW
Cause: Peronospora parasitica, a fungus. Nearly all cultivated and weed plants
of Cruciferae are affected by downy mildew. The several strains of the fungus,
however, are specific to certain groupings of crops, e.g., the radish strain
causes little damage to cabbage. The fungus overwinters in roots or old
diseased plant parts. Spores of the fungus may be spread as contaminants on
seeds. There is no proof that the fungus enters the seed. High humidity, fog,
drizzling rains, and heavy dew are conducive to disease development and
spread. Optimum conditions for development of the disease are night tempera
tures of 46 to 61 F for four or more successive nights, and day temperature
approximately 75 F or lower.
Symptoms: Seedlings: White mildew principally on underside of leaf with
yellowing on upper side. Later the leaf may become papery and die.
Cabbage heads: Sunken black spots which may be minute or larger than 1 inch in
diameter.
Lower leaves: May become severely infected.
Control: The following practices are effective:
1. Increase the ratio of phosphate to potash in the fertilizer to 2:1 or 3:1.
2. Use one of the following spray alternatives:
a. Spray seeding beds with Bravo 6F 1.25 pt/A with water to cover or
Ridomil/Bravo 8lW at 1.5 to 2.0 lb/A.
b. Several formulations of fixed copper are available with labels for
this disease. Fixed copper can cause phytotoxicity on some
varieties at high rates.
c. Spray maneb at 1.2 to 1.6 lb ai/A. Do not apply more than 9.6 lb
ai/A/season. Do not apply within 7 days of harvest.
d. Spray fosetyl-Al (Abette) at 1.6 to 4.0 lb ai/A. Do not apply in
less than 15 gal water/A. Do not apply more than 7 times a season
or within 3 days of harvest.
3. Apply first spray as soon as seedlings appear and repeat three times per
week until plants are set out in field. Spraying for mildew requires complete
coverage of the plant. In general, high gallonage ground application has been
more effective than air application.
Resistance is being incorporated into commercial varieties, but at present
there are no resistant commercial varieties available.
Residues: Bravo--1.125 lb ai/A in water to cover. Tolerance 5 ppm. No time
limitation.
Ridomil/Bravo 8lW - do not apply within 7 days of harvest.
Warning: Resistance to Ridomil has been confirmed in the Northwest. To
minimize further development of resistance, use as follows. If Ridomil is
used at planting (see Cabbage and Cauliflower -- Damping-Off), do not make
foliar applications. Do not use it as a curative spray once disease has
developed. Use only as a preventive spray and only in combination with
another registered fungicide.
---------------------------------------------------------------------------
CABBAGE -- DROP, WATERY SOFT ROT, OR WHITE ROT
Cause: Sclerotinia sclerotiorum, a fungus. This disease survives in crop
refuse and in the soil as sclerotia (hardened fungus bodies), averaging about
the size of a pea. This fungus attacks a wide range of crops and weeds. It
produces microscopic spores that grow first on dead organic matter (often
spent flower petals) and then attack the plants.
Symptoms: The disease occurs for the most part above the ground level a
cottony, white mold. As the cabbage leaves decay, small, dark bodies appear
in the mold. Finally the white mass is replaced by numerous hardened sclerotia
which gradually change in color from white to black.
On seed crops, stem attacks cause severe losses. The diseased tissues eventua
lly bleach white, giving the disease its name "white blight." Sclerotia that
are black on the surface and white inside, associated with this bleached
tissue, are diagnostic.
Control: (1) Rotate using nonsusceptible crops such as grass or grains. (2)
Permit maximum aeration between rows. (3) On seed crops (broccoli, Brussels
sprouts, cabbage, cauliflower, Chinese cabbage, collards, kale, kohlrabi,
mustard, rutabagas, and turnips) the most effective control for this disease
is by aerial spray application of benomyl as Benlate (Pacific Northwest only).
Apply as a thorough-coverage spray using 2 lb in 5 to 10 gal water/A. Add a
spreader for coverage. Make first application at first petal fall make two
additional applications at 14-day intervals if conditions favor development of
the disease. For seed production only, Chipco 26019 is registered in Oregon
and Washington. Apply 2 to 4 lb/A in 20 to 100 gal of water. Use at least 10
gal/A for air applications. Apply at full bloom. Do not feed treated crop or
graze treated area.
---------------------------------------------------------------------------
CABBAGE -- LEAF SPOT
Cause: Alternaria brassicae and A. brassiciola, two fungi. These fungi survive
from year to year on seed and cabbage leaves and roots.
Symptoms: Chlorotic yellow spots develop enlarging to circular areas coated
with black spores. Infection ranges in size from areas barely visible to those
more than 2 to 3 inches in diameter. On infected cabbage seed pods, violet to
tan-colored spots develop, becoming worse in wet weather.
Control: (1) Rotate crops and use clean seed. (2) Seed not known to be clean
may be treated in hot water at a temperature of 122 F for 25 to 30 minutes.
Make a seed germination test following hot treatment. (3) Spray material
listed under downy mildew will help control this disease. (4) For seed
production only, Rovral 50 WP is registered in Washington and Oregon. Apply 2
to 4 lb/A in 20 to 100 gal of water. Use at least 10 gal/A for air applica
tions. An appropriate spreader-sticker is recommended. Apply at full bloom,
pod set, and prior to harvest if disease pressure is severe. Do not use
treated crop debris or screenings for food or feed. Do not graze treated area.
---------------------------------------------------------------------------
CABBAGE -- NEMATODE (Sugarbeet Cyst)
Cause: Heterodera schachtii
Symptoms: First field symptom indicating nematodes is the appearance of
small, conspicuous areas where plants are stunted. Later in the season, areas
of nematode infestation often are marked by absence of plants and presence of
weed patches. In severely infested fields, areas of decline usually can be
identified by excessive leaf wilting during hot weather. Affected areas
increase in size with continuous cropping of host crops.
Infected plants are much smaller than normal ones. Frequently they have a
dense system of secondary roots, called a hairy-root condition. Examination
with a hand lens usually will show numerous small, white, beadlike structures
on roots of infected plants. These structures are lemon-shaped and later
become cysts containing eggs that develop into future generations of nema
todes.
Dwarfed plants that have a tendency to wilt during warm weather should be
pulled and examined for small, white, beadlike females. Soil intended for
cabbage production can be examined for this pest by a simple field test:
Place a teaspoonful of soil i a glass of water, stir briefly, and allow debris
to float to the surface. It is then possible to see and recognize any
brownish cysts that adhere to the sides of the glass. Discovery of nematodes
by this test will not predict severity of infestation but will show that the
field has a nematode history.
Control:
1. Crop rotation is an effective method for reducing nematode population
since this pest has a small host range. In addition to sugarbeets other hosts
are mangel-wurzel, table beet, cabbage, cauliflower, Brussels sprouts,
broccoli, rape, turnip, rutabaga, and radish. Weed hosts are dock, knotweed,
lambsquarters, mustard, nightshade, purslane, saltbush and red root. Any of
these plants that survive from year to year may act as reservoirs in maintain
ing the pests and may counteract much of the value of crop rotation.
These crops may be used in a short-term rotation; beans, sweet clover, corn,
grains, peas, potatoes, and tomatoes. Alfalfa is suitable for a long rotation
period. Length of rotation period should vary with severity of nematode
infection. Slight infestations may require only a 2 year program whereas
severe infestations require a 5 to 6 year interval.
2. Do not return tare to fields.
3. Soil fumigation with Telone II. For rates of application see Soil
Fumigation Guide Chart in the Pesticide Use for Disease Control Section.
Sampling: Cyst nematodes are sedentary endoparasites (see Nematodes--Life
History). Infective second-stage juveniles, adult males (rarely), and cysts
(the dead body of the female which contains eggs) can be obtained from the
soil samples. However, cyst extraction requires a special extraction proce
dure, and if a cyst count is desired it should be noted on the form that
accompanies the sample. During the growing season it is helpful to send roots
as well as soil to assist the diagnosis.
------------------------------------------------------------------------------
CABBAGE -- OEDEMA (Edema)
Cause: Physiological
Symptoms: This nonparasitic disease may occur on any plant part but is usually
found on the lower surface of leaves. The first symptom is a watery blister or
gall that can be few or numerous. The more succulent tissue appears to be more
susceptible. Blisters or galls will turn a dark brown, yellow, or rust color
and give the appearance of a rust or bacterial infection.
The disorder is more prominent when ambient temperatures are lower than soil
temperatures, soil moisture is high, and relative humidity is high. Low
transpiration rates with an increase in water absorption increase cell
pressure, erupting epidermal cells and allowing the inner cells to enlarge and
protrude. This protrusion of the inner cells causes the cells to die and
discolor (yellow, brown, or rust), giving the impression that a parasitic
organism is involved. Any mechanical injury to epidermal cells causes a
similar effect. The most common causes of oedema in the Pacific Northwest are
insect feeding injury (particularly aphids), injury from windblown soil
particles, and damage from chemical applications.
Control:
1. Control insects, particularly aphids.
2. When cabbages are small, control windblown soil particles by sprinkler
irrigation during periods of high wind.
---------------------------------------------------------------------------
CABBAGE -- PHYTOPHTHORA ROOT ROT
Cause: Phytophthora megasperma is a fungus that serves as resistant spores in
the soil and infects its hosts with swimming zoospores under wet conditions.
Symptoms: Above ground portions of the plant wilt. When the root systems are
examined, lateral roots are absent or entirely decayed. The top roots are
entirely decayed or show large, dark lesions along their entire length.
Symptomatic plants are found in wet areas of the field.
Control:
1. Plant only on well-drained soil that has a minimum of low areas where water
can accumulate.
2. Avoid excessive irrigation.
3. Treat seedbed with Ridomil 2E as a surface broadcast of 4 pt/A in 20 to 50
gal/A, or as a 7-inch band application of 2 pt/13,000 linear ft row in 20 to
50 gal/A, or as broadcast incorporated to 2 inches at 4 to 8 pt/A in 20 to 50
gal/A. If plantings are made on beds, broadcast and incorporate prior to
bedding.
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CABBAGE -- SEED TREATMENT
Aids in controlling black rot, Alternaria leaf spot, and damping off.
Apply captan or thiram according to label directions.
Hot water seed treatment -- 122 degrees F for 30 minutes.
Where Pythium is a problem, Anchor flowable at 1.5 fl oz/cwt seed.
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CABBAGE -- TIP BURN
Cause: Physiological disorder. All cabbage varieties grown in Oregon are
susceptible to some degree to tip burn. Some difference between varieties is
recognized. This disorder is aggravated by high fertility and high tempera
tures. Some research indicates that it may be influenced by an imbalance of
nitrogen, potassium, and calcium. Water stress followed by a period of
excessive growth and low humidity is conducive to development of tip burn.
These conditions influence calcium uptake and distribution in the cabbage
head. Amount and frequency of irrigation appear to influence incidence of tip
burn.
Symptoms: A marginal necrosis of internal leaves. The symptoms can extend from
a few, small, brown spots on the edges of the interior leaves to large areas
of the leaf margin turning brown and eventually decaying. External symptoms
are usually absent.
Control: Research in Wisconsin has attributed the disorder to a deficiency of
calcium in the inner leaves research in New York has implicated imbalances of
nitrogen and potash. Other research indicates that high temperatures following
periods of excessive growth can cause tip burn. No effective controls are
known. Holding nitrogen levels to the lowest level possible commensurate with
adequate yields is helpful. Nitrogen rates should not exceed 100 lb/A. The
form of nitrogen may be important with ammonium forms less desirable than
nitrate forms. Do not apply excessive rates of potash or other chemicals that
would compete with calcium uptake. Soil samples should show adequate base
saturation and adequate levels of calcium. Use adequate irrigation to avoid
water stress conditions which would restrict calcium movement to inner leaves.
Harvest when the cabbage is at the optimum maturity to avoid allowing the
cabbage to become excessively firm.
Research from Cornell University describes variety susceptibility to tip burn.
Slightly susceptible: `Superdane', `Flacon', `Hinova', `Atria', `Rudolfo',
`Superkraut', `Krautpaker'.
More susceptible: `Titanic 90', `Roundup', `Bravo', `Krautking', `Little
Rock'.
Quite susceptible: `King Cole', `Quisto', `Superette'.
Very susceptible: `Green Boy', `Rio Verde', `Condor', `Izalco'.
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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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