From: Brian Lo <dragon@csulb.edu>
Newsgroups: rec.gardens
Subject: FAQ: Broccoli
Date: Wed, 1 Mar 1995 09:14:18 -0800
BROCCOLI
Brassica oleracea (Italica Group)
Broccoli, also known as Calabrese in England and much of Europe is
closely related to cauliflower, cabbage, brussels sprouts and kohlrabi. There
is considerable confusion in the scientific and lay literature regarding exact
nomenclature of these vegetables. All will intercross readily and are
classified in the same genus and species.
To complete the confusion, seed catalogues (especially specialty
catalogues) may describe broccoli as heading or sprouting; summer, autumn, or
winter; green, purple, dark purple, copper or purplish-brown, sulphur-colored
or yellowish-green heading, or white-sprouting! Only the green heading types
are discussed below.
VARIETIES (approximately 75-95 days from seeding, depending on variety, season
and planting date).
Fresh Market: Premium Crop, Green Comet (somewhat heat tolerant),
Emperor, Citation and Hi-Caliber. For trial: The varieties, Embassy, Pirate,
Buccaneer, and Sunre 8014 are reported to have some heat tolerance in other
areas and might be considered for trial. Barbados is reported to have good
color. Where club root may be a problem: Pirate and Oregon CR-1.
Processing: Processor specifies varieties to use. The major variety
grown in western Oregon is Gem. Others that have been grown are: Emerald
City, Pirate (reported to have club root resistance), Baccus, Bonanza,
Arcadia, Hi-Caliber, Cruiser, Sunre 8015, Emperor, Citation, Neptune, Pakman
(somewhat heat tolerant). For trial: Everest, Excelsior, Patriot, Barbados.
Note: Some new hybrids suitable for fresh market and/or processing have
resistance or tolerance to an number of important diseases: Downy mildew,
black rot or both: Everest, Premium Crop, Green Comet, Idol, Shogun (cool
season), Crusader, Citation, Hi-Caliber and Futura. Resistance to Pseudomonas
sp. (not Erwinia sp). bacterial head rot: Pirate, Shogun, Green Defender and
Green Valiant. Resistance to club root: Pirate and Oregon CR-1.
Novelty: Romanesco type (unusual spiraled, light green heads):
Minaret. Kailaan type: Green Lance Hybrid, Gai Lohn. Broccoflower:
Alverde, Macerta (really, green cauliflowers); Green Harmony (a true broccoli-
-cauliflower vegetable).
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
Brinker Orsetti Seed Co., 2339 A Technology Parkway, Hollister CA 95023-2513.
408/636-4822
Ferry-Morse Seed Co. POB 4938, 555 Codoni Ave. Modesto, CA 95352
Harris Moran Seed Co. 3670 Buffalo Rd. Rochester, NY 14624
Northrup King Co. Vegetable Seed Group, POB 1827, Gilroy, CA 95021
Petoseed Co. Inc. POB 4206, Saticoy, CA 93303
Rogers NK Seed Co. POB 4272 Boise, ID 83711
Royal Sluis Inc. 1293 Harkins Rd. Salinas, CA 93901
Sakata Seed America Inc. PO Box 877, Morgan Hill, CA
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
Broccoli 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
Broccoli seed numbers approximately 144,000 per pound. Most broccoli
for processing and fresh market is direct seeded (see section on field seeding
below). Pelletizing is not necessary but primed and coated seed is now
becoming popular. Consult your seed dealer about the availability of primed
seed. Some early production of fresh market broccoli is transplanted.
Use certified, or hot-water and fungicide treated seed to protect
against several serious seed borne diseases. Hot water seed treatments are
very specific (122 F exactly, for 25 to 30 minutes; the wet seed then 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: Methyl bromide, Vorlex, Telone II or DD according to
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, broccoli is direct seeded in the field between mid
April and early July. Fresh market broccoli, and late processing broccoli may
be seeded until the end of July.
One-half to 1.5 lbs. of seed may be used per acre for direct seeding.
In Oregon, broccoli is most commonly direct seeded at about 1 lb. of seed per
acre. This allows for a pre-thinning spacing of about 45 square inches per
plant. By careful attention to planting, and spacings, thinning costs could
be minimized.
Processing broccoli is planted at a density of about 20,000 to 30,000
plants per acre to produce a large head size. Choose an in-row spacing
arrangement that allows adequate plant density and easy thinning (some
multiple of the final spacing) which should be about 8-10 inches in the row.
Between-row spacings should allow adequate access for cultivation and hand
harvest-aid equipment and labor. A common practice is to alternate rows
spaced 12-14 inches apart with wider spacings of 28-30 inches for harvest
labor and wheel tracks.
For fresh market, use spacings as indicated for processing but thin to a
final spacing of 6-8 inches in the row.
Use a precision seeder, such as a Stanhay, or Gaspardo vacuum planter,
to drop a seed every 3-5 inches within the row. Thin to the desired stand
after the first true leaves have formed. Use only the highest quality, sized
and density graded seed.
Preparation for direct seeding needs considerable attention. A mode-
rately fine-textured soil, free of rocks, clods and trash, firm and very
level, is required for precision seeding. Tilling the soil excessively,
increases the risk of crusting. Attempt to keep soil aggregates about 1/4 to
1/2 inch in size.
To insure uniform and successful stand establishment, use vermiculite
anticrustant or have solid set irrigation available to keep soil moist and
free from crusting until the stand has been established.
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 broccoli. 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 broccoli 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 an 18" row spacing,
with plants 9" apart in the row. 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 broccoli 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 STARTER 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 mono-ammonium phosphate fertilizer
in a 55 gallon drum of water.
FIELD FERTILIZATION
NITROGEN (N)
A total application of 150-200 lbs. N/A is suggested. Growers in the
Willamette Valley often use rates of 250-300 lbs. particularly with varieties
where several harvests of side shoots would be desired for maximum yields.
When high rates of N are used, stem splitting could become a problem.
Research data indicates that stem splitting might be reduced if the extra N is
applied in several sidedressings rather than in one large application.
Broadcast about half of the N just prior to direct seeding or trans-
planting or band 60-90 lbs N/A with the phosphorus. For both direct-seeded
and transplanted crops, side-dress 75 to 100 lb./acre of nitrogen at time of
last cultivation, or 1 to 2 weeks before the first cutting. At the higher
rates, use two applications, with the first application when the broccoli is
6-8 inches tall and the second about 2 weeks later.
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 4th 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 50 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 aci-
difying 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)
Broccoli 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. Com-
pared to other vegetables broccoli 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 Horti-
culture and Soils Department research faculty.
These recommendations are quoted from OSU Fertilizer Guide FG 27.
IRRIGATION
After the stand has been established irrigate to maintain uniform soil
moisture. About 10-14 inches of water may be necessary in western Oregon
depending on seasonal variation, variety, planting date and the number of
times the field is harvested.
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.
HEADING DISORDERS
Blindness: A percentage of the plants in the field form no heads at all
due to some injury. The plant responds by producing numerous shoots at near
ground level. The injury can be due to insect (cabbage maggot, lygus bug,
diabrotica) damage to the growing point usually when the plant is small, or if
these occur just at the beginning stages of head initiation.
Leafy heads: The presence of leaves within the head is often due to
high temperature coupled with lush growth due to excess water and nitrogen.
Large, coarse buds: Bud size is a function of variety, but all develop
large buds as the heads become mature. High temperature and delayed harvest
may result in excessively large or open buds. Varieties differ in their field
holding characteristics.
HARVESTING HANDLING AND STORAGE
In the Willamette Valley, broccoli harvest for processing begins about
June 25 and continues to October 31. The prime harvest period for processing
is July 15 to the end of September. Harvest of fresh market broccoli may
extend through November.
Yields of processing broccoli average approximately 5.5 tons/acre with
good yields at 7.5 tons. Fresh market average yields are reported at 95
cwt./acre with good yields at 120 cwt./acre.
Harvest broccoli heads when the buds are still small and tightly closed,
and before the heads are fragmented. Heads should be tight, and the individual
flowers in the clusters should not show yellow petals. Side heads develop
rapidly in some varieties following removal of the terminal head, and harvest-
ing may continue for several weeks.
Broccoli is highly perishable, and it is usually held for only a brief
period as needed for orderly marketing. If in good condition and held with
adequate air circulation and spacing between containers to avoid heating,
broccoli should keep satisfactorily 10-14 days if held at 32 F, 90-95%
humidity.
STORAGE (Quoted from USDA Ag. Handbook # 66):
Store broccoli and 32 F. and relative humidity of 95 to 100 %. Broc-
coli is highly perishable, and it is usually stored for only a brief period as
needed for orderly marketing. Broccoli should be hydrocooled or packed in ice
immediately after harvest and kept at 32 F. to maintain good salable condi-
tion, fresh green color, and vitamin C content. If in good condition and
stored with adequate air circulation and spacing between containers to avoid
heating, broccoli should keep satisfactorily 10 to 14 days at 32 F. Longer
storage is undesirable because leaves discolor, buds may yellow and drop off,
and tissues soften. The respiration rate of freshly harvested broccoli is
very high - comparable to that of asparagus, spinach, or sweet corn. Thus,
like these crops, broccoli must be cooled immediately after harvest to rapidly
lower the respiration rate and be kept at low temperature for maximum shelf
life.
A controlled atmosphere of 10% carbon dioxide and/or 1% oxygen can in-
crease the shelf life of good quality broccoli held above 40 F. An atmosphere
with 10% carbon dioxide retards yellowing and toughening, and one with 15%
carbon dioxide has the same retarding effect but can induce persistent off-
odors. A 1% oxygen atmosphere retards yellowing but one with 0.1 to 0.25%
oxygen can cause severe injury and result in off-odors and off-flavors in
cooked broccoli. Film wraps can be beneficial in maintaining high relative
humidity and extend the storage life. They should be perforated or be
sufficiently permeable, however; otherwise, an atmosphere that causes injury
and/or off-odors, particularly at 32 F., may develop within the wraps.
Broccoli should not be stored with fruits, such as apples or pears, that
produce substantial quantities of ethylene, because this gas accelerates
yellowing of the buds.
PACKAGING
For fresh market two or three heads are bunched together and packaged
14-18 bunches per 20-24 lb. "half carton" container. Containers should be
liquid iced for quick cooling and maximum shelf life.
PEST CONTROL FOR BROCCOLI
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 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 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
Rundup RT
(E. Washington and
Idaho only)
or Honcho +
nonionic surfactant
Apply to actively growing weeds either preplant in conjunction with site
prepartion or preemergence crops listed on the label. Consult label for
specific rates, times of application, and perennial species controlled.
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
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
trifluralin 0.5 to 1.0 lb ai/A
Treflan
Apply before planting and incorporate 2 to 3 inches deep by
cross-disking 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).
------------------------------------------------------------------------
bensulide 5 to 6 lb ai/A
Prefar
(direct-seeded broccoli)
Apply preplant and incorporate 1 to 2 inches deep simultaneously or
immediately after application by cross-disking or using a PTO rotary
tiller. Consult label for planting sensitive crops within 18 months.
Do not apply more than once every 12 months. (Inhibits roots of seed-
lings).
______________________________________________________________________________
PREEMERGENCE
Weed Treatment Active Ingredient Per Acre and Application Comments
------------------------------------------------------------------------------
bensulide 5 to 6 lb ai/A
Prefar
(direct-seeded broccoli)
Apply preemergence to crop and weeds, preferably soon after planting
followed with 1 inch of water by sprinkler irrigation. For furrow irri-
gation, thoroughly saturate the bed top. Sometimes the first flush of
weeds must be controlled with cultivation before the herbicide begins
to control grass. Note other comments above.
------------------------------------------------------------------------
Napropamide 1 to 2 lb ai/A
Devrinol
Selectivity is based on placement above the seed or transplant depth.
For direct seeded crops, apply to soil surface immediately after
planting and sprinkler irrigate within 24 yours 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)
------------------------------------------------------------------------
oxyflourfen 0.25 to 0.5 lb ai/A
Goal
(transplanted broccoli)
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 inch 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 temperature, or low fertility. Resistant
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 Dibrom - 1 to 2 lb
Myzus persicae
Pyrellin - 1 to 2 pt.
Both species gray, mealy plant
lice forming colonies on foliage, diazinon - 0.5 lb
on or in heads or in buds. Weak-
en plants and constitute an Lorsban 50W - 1 lb
adulterant in processed foods.
Metasystox-R - 0.375 to 0.75 lb
For effective aphid control, ap-
plication of insecticides should Orthene 75S - 0.5 to 1.0 lb
start with first appearance of
aphids and be continued at reg- endosulfan - 0.75 to 1.0 lb
ular intervals as aphids appear.
This is particularly true of Di-Syston - 1 lb
broccoli and cauliflower to Apply granules as a band on
prevent aphids from concealing each side of seed furrow or
themselves in heads. transplanted row at planting,
or as a side dressing after
NOTE: To be effective Di-Syston plants become established.
application should be followed by Liquid injections can be made
sprinkler or furrow irrigation. in similar manner. Do not apply
Di-Syston is relatively insoluble directly to seed. See label for
and requires high soil moisture complete details.
to give best results.
dimethoate - 0.25 to 0.5 lb
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
ai/1000 row ft.
diazinon - 2 to 3 lb
---------------------------------------------------------------------------
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 malathion - 1.5 to 2.5 lb
leaves of wild and cultivated
crucifers. Particularly serious Di-Syston - 1 lb
on seedlings.
Asana - 0.03 to 0.05 lb
NOTE: Carbaryl and endosulfan
combined together have given Lorsban - 50W 1 lb.
most effective control.
permethrin - 0.05 to 0.2 lb
Larvin - 0.4 to 0.8 lb
Pyrellin - 1.5 to 2 pt
---------------------------------------------------------------------------
Garden symphylan Dyfonate - 2 lb
Scutigerella immaculata
Telone II or C-17 - preplant
Small, white, centipede-like
animals in the soil. Mocap - 2 to 3 lb
diazinon - 10 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.
---------------------------------------------------------------------------
Slugs metaldehyde baits
---------------------------------------------------------------------------
Thrips malathion - 1.87 lb
Frankliniella sp.
methyl parathion - 0.3 to
Adults about 1/25 inch in length. 1.5 lb.
Yellowish to black in color. An
occasional problem in fresh
market cabbage.
---------------------------------------------------------------------------
Wireworms diazinon - 3 to 4 lb
Ctenicera and
Limonius spp. Telone II or C-17 - preplant
Brown, jointed larvae of click beetles.
---------------------------------------------------------------------------
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 other cab- methoxychlor - 2.25 lb
bage "worms." State insecticide applica-
tions when the worms are still small. endosulfan - 0.75 to 1.0 lb
Inspect the plants a day or so after each
treatment for success of control. Examine permethrin - 0.05 to 0.2 lb
plants often in late summer and fall for
new infestations. Be sure insecticides malathion - 1.25 lb
reach both sides of leaves. Choice of
insecticide is dependent in part on Phosdrin - 0.5 lb
nearness to harvest. Parathion and
phosdrin give better control of loopers carbaryl - 2 lb
when temperatures are below 70 F.
Asana - 0.03 to 0.05 lb
NOTE:
Orthene 75S - 1 lb
Suitable registered wetting agents should
be added to most of the spray solutions of pyrellin - 1 to 2 qt
the mentioned insecticides. The wetting
agent will aid in spreading and sticking Larvin - 0.6 to 1 lb
of the sprays to the waxy leaves and
plant surfaces. diatect - 1 to 3 lb formulation
---------------------------------------------------------------------------
Diamondback moth endosulfan - 1 lb
Plutella maculipennis
malathion - 1.25 to 2.5 lb
Small, pale yellowish-green larvae
with erect black hairs. Eats holes diazinon - 0.5 lb
in foliage. Adults are small gray
or grown moths with white marks on carbaryl - 2 lb
forewings that form a diamond when
wings are folded. Rotenone - 0.35 lb (ICW only)
Imported cabbage worm trichlorfon - 0.5 to 1.0 lb
Pieris rapae
Phosdrin - 0.5 lb
Caterpillars are soft, velvety
green with faint yellow stripes. Phosdrin - 1.0 lb (ICW only)
Adult is a white butterfly with
black spots. Larvin - 0.6 to 1 lb
diatect - 1 to 3 lb
Monitor - 0.5 to 1.0 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.
Lorsban 4E - 1 lb
Larvin - 0.4 to 0.8 lb
Pyrellin - 1 to 2 pt
--------------------------------------------------------------------------
Cutworms and Asana - 0.03 to 0.05 lb
Armyworms
endosulfan - 1 lb
Several species.
Treat when worms are small. carbaryl - 1 to 2 lb
permethrin - 0.05 to 0.2 lb
Bacillus thuringinesis - 1 to 2 qt
Lorsban 50W - 1 lb
Larvin - 0.4 to 0.8 lb
______________________________________________________________________________
______________________________________________________________________________
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.
BROCCOLI -- BACTERIAL SOFT ROT (HEAD ROT)
Cause: A bacterium, Erwinia carotovora subsp. carotovora), is found in soil,
and in irrigation water. The bacteria enters the plant through natural
openings and wounds caused by insects and equipment. The head rot phase of the
disease usually starts where water stands on the heads after rain or irriga-
tion.
Symptoms: The plant tissue at first appears watersoaked and rapidly breaks
down into a soft, mushy rot. Any part of the plant can be affected but the
most serious economic loss occurs when heads are infected.
~Control:
1. Avoid excessive irrigation and irrigation that does not dry off the plants
rapidly.
2. Increasing spacing within and between rows will increase air drainage and
decrease rot.
3. There have been reductions in head rot in the Willamette Valley by the use
of Kocide 101 sprays. Apply Kocide 101 at the rate of 2 lb product/A starting
when heads are as large as your fist at weekly intervals until the center
heads are harvested.
4. The varieties, `Pirate', `Shogun', `Green Valiant', and `Green Defender',
are reported to be resistant to Pseudomonas sp. but have not been tested in
Oregon against Erwinia.
Residues: Copper--exempt.
---------------------------------------------------------------------------
BROCCOLI -- 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 broccoli variety `Ore. CR-1' is resistant to some strains of the
fungus.
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 broccoli 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 com-
plete 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 rototilledand
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 applicatiion 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--broccoli: 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.
--------------------------------------------------------------------------
BROCCOLI--DAMPING-OFF
Treat seed with Anchor flowable 1.5 fl oz/cwt seed, or where Pythium sp. are a
problem, apply Ridomil 2E. (Not registered in British Columbia.)
Broadcast: Apply 4 pt Ridomil 2E/A at planting in 20 to 50 gal water.
Banded: Apply 0.5 to 1 pt Ridomil 2 E/13,000 lin ft of row in 20 to 50 gal
water.
Broadcast and incorporated: Apply 1 to 2 pt/A Ridomil 2 E as a broadcast
application in 20 to 50 gal water/A and incorporate into the top 2 inches of
soil. If planting on beds, broadcast and incorporate before bedding. To
minimize the development of fungi resistant to Ridomil, do not make foliar
application if Ridomil is used at planting. (See broccoli -- Downey Mildew).
--------------------------------------------------------------------------
BROCCOLI -- DOWNY MILDEW
Cause: Peronospora parasitica, a fungus.
Symptoms: The first sign of the disease is the appearance of small, light
green-yellowish lesions on the upper leaf surface, later showing on the
undersurface. The spot turns yellow as it enlarges. A bluish-white fungus
growth can be seen growing in the spots on the underside of the leaf.
On the stalks--External: Spots similar to the leaf spots. Internal: Streaks of
brown to purple tissue, often in a net necrosis pattern. The streaks may
extend up to the small florets of the curd. Stunting of the curd may be the
result of this infection.
~Control: All commercial processing varieties are very susceptible to the
disease. At present there is no satisfactory control of systemic infection.
The systemic phase of the disease is the most destructive since it renders the
heads useless for the freezing trade. The streaking is difficult to detect
without breaking the stalk for examination. Spring-planted, summer-harvested
crops experience less problems than fall harvested.
The following fresh-market varieties have tolerance to the disease and have
performed well in the Willamette Valley: `Futura', `Citation', `Premium
Crop', `Green Comet', `Green Valiant', and `Crusade'.
Spray Ridomil/Bravo 81W at 1.5 to 2.0 lb/A. (Not registered in British
Columbia.)
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.
Spray chlorothalonil (Bravo) at 1.17 lb ai/A. In British Columbia, do not
apply within 7 days of harvest.
Spray with fixed copper. Several formulations of fixed copper are available.
Check product label for rates. Phytotoxicity can occur at high rates on some
varieties.
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.
Chlorothalonil (Bravo)--No time limitation. Tolerance 5 ppm.
Ridomil/Bravo 81W - 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 Broccoli -- 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.
--------------------------------------------------------------------------
BROCCOLI -- RINGSPOT (BLACK BLIGHT) IN SEED PRODUCTION
Cause: Mycosphaerella brassicicola, a fungus that attacks cabbage, cauliflow-
er, 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.
______________________________________________________________________________
______________________________________________________________________________
---------------------------------------------------
---------------------------------------------------
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.
---------------------------------------------------
---------------------------------------------------