CHILE PEPPER PRODUCTION IN
CALIFORNIA
RICHARD SMITH, UCCE Vegetable Crop Advisor, Monterey County; JOSÉ
L. AGUIAR, UCCE Farm Advisor, Riverside County; AZIZ BAAMEUR, UCCE
Farm Advisor, Santa Clara County; MICHAEL CAHN, UCCE Irrigation and
Water Resources Advisor, Monterey County; MARITA CANTWELL, Extension
Vegetable Crops Specialist, Department of Plant Sciences, University of California,
Davis; MARIA DE LA FUENTE, UCCE Farm Advisor, San Benito County;
TIMOTHY HARTZ, Cooperative Extension Vegetable Crops Specialist, Department
of Plant Sciences, University of California, Davis; STEVEN KOIKE, UCCE Plant
Pathology Farm Advisor, Monterey County; RICHARD MOLINAR, UCCE Farm
Advisor, Fresno County; ERIC NATWICK, UCCE Farm Advisor, Imperial County;
TREVOR SUSLOW, Cooperative Extension Postharvest Specialist, University of
California, Davis; ETAFERAHU TAKELE, UCCE Area Farm Advisor, Southern
California Counties
PRODUCTION AREAS AND SEASONS
California has four main chile pepper (Capsicum
annuum L.) production areas: the southern desert val
leys (Imperial and Riverside Counties), the southern
coast (San Diego, Orange, and Ventura Counties), the
Central Coast (San Luis Obispo, Monterey, San Benito,
and Santa Clara Counties), and the Central Valley
(Tulare, Fresno, and San Joaquin Counties).
Nearly all fields in the southern desert valleys are
transplanted in late January or February for harvest
from late April through June. On the southern coast,
planting also begins in January and continues through
May for harvest from May through September. In the
Central Coast, planting is done from March to June
for harvest from August to November. Planting in the
Central Valley begins in Fresno County in February
under plastic tunnels and hotcaps and moves through
counties farther north over the next four months for
harvest from late May to November.
CLIMATIC REQUIREMENTS
Chile peppers are warmseason crops, sensitive to
freezing temperatures at any growth stage. The rate
of seed germination decreases rapidly when soil
tempera tures are below 77ºF (25ºC), with germination
slow below 68ºF (20ºC). Day temperatures of 75º
to 85ºF (23.9º to 29.4ºC) with night temperatures
about 50º to 60ºF (10º to 15.6ºC) are ideal for growth.
Although tolerant of temperatures of about 100ºF
(37.8ºC), such extreme conditions can reduce effective
pollination, fruit set, and yield.
VARIETIES AND PLANTING
TECHNIQUES
Varieties. Chile peppers comprise five species in the
genus Capsicum and include a wide variety of pepper
types. The species C. annuum is the most commonly
cultivated. The fruits of C. annuum range in size and
shape from small cherrylike fruits to conical forms
to slender fruits up to 9 inches (23 cm) long and
from mild to extremely pungent, as measured by the
Scoville heat index. Relatively mild chile types like
Anaheim peppers may rank as low as 500 Scoville
heat units, while habanero peppers rank over 300,000.
Pungency is due to the presence of capsaicin, a
colorless, odorless alkaloid that is concentrated in the
placental tissue.
Common chile pepper groups and varieties include
the following. Paprika pods are long dark red with
little pungency. They are used for the production
of red pigment and flavoring. Jalapeño pep pers are
often harvested as green fruit for freshmarket use.
A sizeable proportion of the production is also sold
to processors. Anaheim, or New Mexican, are long,
cylindrical peppers 7 to 9 inches (18 to 23 cm) long.
They are harvested green for fresh use as well as
canning, and ground red dehydrated pods are used
in sauces. They range from varieties that have little
Vegetable
Production Series
vric.ucdavis.edu
UC Vegetable Research
& Information Center
University of California
Agriculture and Natural Resources
http://anrcatalog.ucdavis.edu • Publication 7244
CHILE PEPPER ACREAGE AND VALUE
Year
Harvested
Acreage
Average Yield
(Tons/Acre)
Gross
Value ($/
Acre)
2009 5,900 17.5 7,726
2008 5,700 16.25 8,543
2007 5,800 15.50 10,664
2006 5,500 16.50 8,019
Source: California Department of Food and Agriculture-
California Agricultural Resource Directory 2010
http://vric.ucdavis.edu
http://anrcatalog.ucdavis.edu
pungency (NuMex Conquistador and Anaheim)
to varieties that have appreciable pungency (e.g.,
Sandia). Wax peppers pods vary great ly in size and
shape and are usually yellow when immature. They
can be sweet or pungent and are used fresh or for
pickling. Wax types are also called Güero, Banana,
and Hungarian Wax. Varieties include Caloro, Floral
Gem, Matador, Sweet Banana, and Santa Fe Grande.
A large number of other chile pepper varieties
belong to other species of Capsicum. Examples are C.
chinenses, which includes habanero, Scotch bonnet,
and rocotillo chiles; C. baccatum, which includes South
American types known as aji chiles; C. frutescens,
which includes Tabasco chiles; and C. pubescens,
which includes rocoto and manzano chiles.
Planting. Nearly all fields in the southern desert
val leys and southern coastal regions are transplanted,
as are most fields in the southern half of the
Central Valley. Many processing production fields
are commonly direct seeded with open pollinated
varieties. However, an increasing number of hybrid
varieties are available for some types of chiles
that have higher yield potential, and their use has
increased in recent years.
In the southern desert valleys, Central Valley, and
southern coastal areas, peppers are usually grown
as double rows on raised beds, 60 to 72 inches
(1.5 to 1.8 m) apart, with plastic mulch and drip
irrigation. Much of the acreage is fumigated before
transplanting. These three practices promote earliness
and yield, and in the southern coastal areas, help
compensate for the high cost of land and water. In
Fresno County some smaller growers plant on beds
36 to 40 inches (0.9 to 1.0 m) apart with one seed line.
Plastic tunnels or hotcaps are sometimes used to give
earlyseason frost protection, but this practice adds
considerable cost of production. Central Coast fields
are mostly transplanted, with some direct seeding.
Planting in doublerow beds is more common than
in singlerow beds. Elsewhere in the state, neither
fumiga tion nor plastic mulching are common, and
a wide vari ety of field configurations are used. Bed
width varies from 30 to 66 inches (0.8 to 1.7 m), with
one or two rows of plants per bed; inrow plant
spacing ranges from 8 to 16 inches (20.5 to 40.5 cm).
Where direct seeding is done, 0.5 to 2 pounds per
acre (0.6 to 2.2 kg/ha) of seed is used. Higher rates
are used early in the season when soil temperature
is suboptimal; pepper seed germinates slowly and
erratically below 68ºF (20ºC).
SOILS
Many soil textures are used for chile pepper produc
tion. Sandy soils are preferred for the earliest
plantings because they warm more rapidly in
the spring. Heavier soils can be quite productive,
provided they are well drained and irrigated with
care. Phytophthora root rot, a soilborne fungal
disease, can be a serious problem in soils saturated
from excessive irrigation or rainfall.
IRRIGATION
Chile pepper is typically drip or furrow irrigated.
Statewide, greater than 80 percent of the crop
is grown under drip irrigation. Furrow is most
commonly used in areas such as the Central and
Imperial Valleys. Overhead sprinklers are typically
used for seedling or transplant establishment but
are seldom used for the entire production season.
Where furrow irrigation is used, irrigation frequency
depends on soil type, environ mental conditions, and
crop growth stage. Although peppers are moderately
deeprooted, they are quite sensitive to moisture
stress. Stress during bloom can cause substantial
reduction in fruit set, while stress dur ing early fruit
growth can induce blossom end rot. Soil moisture
stress can also minimize foliage cover, increas ing
sunburning of fruit. However, care must be exercised
to prevent overwatering, which can induce root rot
caused by Phytophthora capsici.
With drip irrigation, growers use either one or
two drip lines per bed; the lines may be buried 8 to
10 inches (20 to 25.5 cm) below the soil surface to
allow the tape to be used for multiple crops, or they
can be placed on or just below the soil surface to ease
installation and removal of the tape. Surfaceplaced
tape and shallowly buried tape often provide the best
uniformity of moisture across the width of the beds.
Transplants are often established with drip. Usually
the beds are moistened with a preirrigation before
transplanting. Frequency of irrigation can vary from
once or twice a week early in the season to almost
daily during times of peak water demand.
Water requirements of chile peppers depend on
the irrigation method, soil type, and weather regime.
Irrigation requirements range from 1.8 to 2.8 acrefeet
(2,200 to 3,453 m3) for drip irrigated crops and 2.5
to 4 acrefeet (3,083 to 4,934 m3) for furrowirrigated
crops. Irrigation requirements can be determined
by a combination of weatherbased scheduling and
soil moisture monitoring. Irrigating to maintain soil
moisture tensions below 40 cbars (kPa) minimizes
water stress during critical stages of development
such as flowering and fruit set.
Water use of chile peppers can be estimated using
reference evapotranspiration data (ETo) adjusted
for a crop coefficient, which is closely related to the
percentage of canopy cover shading the surface of the
bed. A maximum crop coefficient of 1.05 corresponds
with maximum canopy cover (> 90%). In fields where
overhead sprinklers are used during transplant
establishment, the crop coefficient ranges between
2 • Chile Pepper Production in California
0.2 to 0.4, depending on the irrigation frequency,
to account for water lost by evaporation from the
soil surface. With the exception of surfaceplaced
or shallowly buried tape, in which water could be
lost by evaporation from the wetted surface of the
bed, plastic mulches would have minimal impact
on the crop coefficient, other than hastening canopy
growth. The California Irrigation Management
Information System (CIMIS), coordinated by the
California Department of Water Resources, provides
daily estimates of reference evapotranspiration for
most production regions of California at their Web
site, http://wwwcimis.water.ca.gov.
FERTILIZATION
Chile peppers require moderate to high rates of
fertiliz er. Preplant phosphorus (P) application of 80
to 200 pounds per acre (90 to 224 kg/ha) of P2O5
is common; a higher rate is appropriate for fields
with limited soil phosphorus availability (
bicarbonate extractable P), while fields with soil test
phosphorus > 25 ppm can be adequately supplied
by the lower end of this range. Inseason phosphorus
fertilization is seldom required. Many California soils
have adequate potassium (K), but in some fields
potassium deficiency may be encountered. Soils with
ammonium acetate exchangeable potassium less
than 150 ppm should be fertilized with potassium;
appropriate seasonal rates vary from 50 to 150
pounds per acre (56 to 168 kg/ha) of K2O, depending
on soil test values.
Nitrogen fertilization rates tend to be high, with
many growers applying 250 pounds of nitrogen
per acre (280 kg/ha) or more seasonally. It is a
widespread belief that high nitrogen rates increase
plant vigor, foliage cover, and fruit size, which in turn
increases yield and decreases sun burn damage to
fruit. However, with efficient irrigation management
a seasonal rate of 200 pounds of nitrogen per acre
should be sufficient under most field conditions. In
fields harvested for fresh market over a prolonged
peri od, somewhat higher seasonal nitrogen rates
may be justified. Nitrogen fertilizer should be
delivered in multiple applications through the season,
with no more than 20 to 30 percent of the seasonal
total applied preplant. In furrowirrigated fields,
nitrogen and potassium are applied preplant and
in one or more sidedressings; lateseason waterrun
applications may also be done. Where drip irrigation
is used, nitrogen and potassium can be applied in
numerous fertigations throughout the sea son.
INTEGRATED PEST MANAGEMENT
Detailed information about IPM for peppers is
available at the UC IPM World Wide Web site, http://
www.ipm.ucdavis.edu. Herbicides, insecticides, and
fungicides should always be used in compliance with
label instructions.
Weed management. It is important to control
annual and perenni al weeds in pepper production
to maintain acceptable yield and quality. The
slow initial growth of pepper seedlings in direct
seeded fields and transplants makes weed control
challenging in this crop. Fields with heavy weed
infestations or with perennial weeds such as field
bindweed or yellow nutsedge should be avoided.
Dark colored (e.g., black or brown) plastic mulch
provides control of weeds except for in the planting
hole and furrows. Herbicides can be applied beneath
plastic mulch to control broadleaf weeds; other
herbicides can be used to treat the furrows when
plastic mulch is used and cultivation is not an option.
Fumigation provides broadspectrum weed control
in fields where it is used. In unmulched chile pepper
production, preplant or preemergence herbicides
that control broadleaf and grass weed species are
used in conjunction with mechanical cultivation
to further improve weed control on the bed tops
and furrows. The use of buried drip irrigation
reduces weed pressure by keeping the soil surface
drier. Handweeding of fields is usually required to
remove weeds not controlled by the above mentioned
techniques.
Insect identification and management. A wide
vari ety of insect pests can cause significant damage to
pep per plantings. Flea beetles (Epitrix and Phyllotreta
spp.) and the palestriped flea beetle (Systena
blanda), cutworms (Agrotis and Peridroma spp.), and
wireworms (Limonius spp.) are common seedling
pests that periodi cally require control measures. Later
in the season, several species of aphids including
the green peach aphid (Myzus persicae) can build
to damaging levels; more importantly, they serve
as vectors for several serious virus diseases. Three
species of thrips are implicated in the transmission of
the tomato spotted wilt virus (TSWV): western flower
(Frankliniella occidentalis), onion (Thrips tabaci), and
chili (Scirtothrips dorsalis). Beet armyworm (Spodoptera
exigua) and tomato fruitworm (Heliocoverpa
zea) can damage foliage as well as fruit. Pepper
weevil (Anthonomus eugenii) can be a serious pest
of pepper fruit; damaging weevil pop ulations are
generally confined to southern California. Pepper
psyllid (Bactericera cockerelli) can build up large
populations rapidly and produce large amounts
of honeydew during their feeding, which can lead
to a buildup of sooty mold on fruit. Broad mites
(Polyphagotarsonemus latus) feed on the undersides of
leaves and young fruit. Broad mites inject salivary
toxins as they feed, which results in twisted,
distorted growth, downward curling of leave edges,
distortion of flowers and buds that do not open, and
dead terminal buds. This injury may be confused
3 • Chile Pepper Production in California
http://wwwcimis.water.ca.gov
http://www.ipm.ucdavis.edu
http://www.ipm.ucdavis.edu
4 • Chile Pepper Production in California
with herbicide injury, nutritional deficiencies, or
physiological disorders. They are most prevalent in
the southern part of the state. Look for characteristic
damage using a 20× hand lens to inspect the
underside of the leaves for the mites and their eggs.
Several miticides are registered for broad mite control,
but insecticidal oils or soaps are usually just as
effective and less toxic to the environment. Release
of predator mites such as Neoseiulus californicus can
provide control in enclosed production systems such
as high tunnels or greenhouses. Leafminer (Liriomyza
spp.) can build to populations sufficient to defoliate
plants. Heavy use of broadspec trum insecticides
(used to control other pests) destroys the complex
of beneficial insects that usually keep leafminer
populations in check. A comprehensive IPM program
using insecticides that do not disrupt beneficial
populations can minimize this problem.
Disease and nematode identification and
management. A variety of diseases and disorders
affect chile peppers and reduce their yield and fruit
quality.
Pathogenic diseases. Phytophthora root rot
(Phytophthora capsici) is widely distributed in
California peppergrowing regions. Disease
severity is enhanced by excessive soil moisture,
with plant symptoms concentrated in low areas,
at the end of furrowirrigated fields, or in areas of
restricted drainage. There are no effective chemical
control measures; control depends primarily on
proper irrigation management. Genetic tolerance
to Phytophthora root rot is now available in
some recently released hybrid varieties. Peppers
are susceptible to infection by Verticillium wilt
(Verticillium dahliae), and occasional serious economic
loss to that pathogen occurs.
There are several potentially damaging foliar
pathogens of pepper. Bacterial spot (Xanthomonas
campestris pv. vesicatoria), which can be seedborne or
may overwinter in crop residue in soil, may be severe
in warm, humid conditions. Extended wet conditions
are rare in California pepperproducing areas, so
bacterial spot is not a major field problem. However,
if a field is sprinkler irrigated, the disease can cause
extensive spotting on leaves and lesion formation on
fruit. In circumstances such as greenhouse production
of transplants or extended wet weather, chemical
control may be needed. Powdery mildew (Leveillula
taurica) can occur in severe outbreaks that result in
significant defoliation and subsequent sunburning
of the fruit. A chemical control program should be
initiated at the first sign of powdery mildew.
Viruses. Viruses are the most common and
damaging pepper disease problem. The major aphid
vectored viruses are cucumber mosaic virus (CMV),
pepper mottle virus (PeMV), tobacco etch virus (TEV),
and potato virus Y (PVY). Occurring alone or in
combination, these viruses can devastate entire fields,
and their appearance and severity are unpredictable.
Insecticide applications are generally ineffective in
preventing virus diseases since virus transmission
can take place during brief insect feeding periods;
insecticides may be marginally beneficial in
controlling subsequent infield spread of the viruses
by colonizing aphids. Alfalfa mosaic virus (AMV) is
relatively common in California pepper fields but
does not often cause significant yield loss. Curly
top virus, vectored by the beet leafhopper (Circulifer
tenellus), occurs in the coastal, Coachella, and Central
Valleys but seldom causes serious economic losses.
Tobacco mosaic virus (TMV), historically a serious
pepper disease, is now controlled primarily by the
use of resistant varieties. Significant losses still occur
periodically where particularly virulent TMV strains
are present. Tomato spotted wilt virus, vectored by
thrips, is potentially a devastating pathogen that is
especially prevalent on pepper grown on the coast,
though TSWV can be found in other regions as well.
The distinctive ring and blotch discoloration of fruit
makes this disease a significant economic concern. A
closely related tospovirus, Impatiens necrotic spot virus
(INSV), has been detected on pepper but is not yet an
economic issue.
Nematodes. Soilborne pests of significance include
the rootknot nematode (Meloidogyne spp.). Rootknot
nematode is a problem only in relatively sandy s
