Carrots originated in south Asia, in what are now Afghanistan, Iran, and Pakistan. By 900 to 1000 A.D. they were being grown from India to
the Eastern Mediterranean. By the 1300s purple and yellow carrots had spread as far as western Europe and China. The first appearance of
white and orange carrots in Europe was during the 1700s. Orange carrots soon displaced other colors and today predominate throughout the
world. Nevertheless, other colors of carrots are commercially available. See the section on Nutritionally Enhanced and Unusually Pigmented
carrots under Varieties, below. Carrots are an excellent source of beta-carotene (pro-vitamin A). High-pigment varieties are also an excellent
source of antioxidants thought to help prevent cancer.
TYPES
Paris market (approximately 60 days): Round to "top-shaped"
roots averaging 2-3" in diameter. Grown for specialty fresh markets.
Amsterdam forcing (approximately 65 days): Roots are small
to medium (ave. 5"), slender cylindrical shape, blunt tipped, small core and smooth skinned.
Foliage and crown are small. Grown for bunching and as a quick maturing crop for market or
cello-packing. Also used for freezing and canning especially for "baby carrot" packs where
whole-root baby carrots are required. Most baby carrots are "cut and peel" (see below).
Nantes (approximately 70-100 days): Roots are medium in size
(ave. 6"), cylindrical, generally with a
slight shoulder, blunt tipped but sometimes tending to taper.
Intermediate in foliage and crown size. Quality is between Amsterdam forcing and Berlicum.
Because of its high sugar content and tenderness, some varieties of this type have a tendency to split
under late season western Oregon conditions. Grown for cello-packing, bunching and processing.
Imperator (approximately 100-120 days): Very long (ave. 9-10"),
tapered, slender roots, small core,
excellent color, smooth skinned. Foliage is intermediate with a
small crown. Grown for market, often bunched, and sometimes for processing, primarily for sliced packs.
Berlicum (approximately 100 days): Roots are large (ave.
8-9"), cylindrical or only slightly tapering, resembling a large Nantes. Grown mainly for processing.
Danvers (approximately 80-120 days): Roots average 7",
intermediate between conical and cylindrical. Upper portion of the root is tapered toward the
crown. Pointed or somewhat stumped root tip. Matures about the same time as the Chantenay group.
Chantenay (approximately 80-180 days): Roots are medium size
(ave. 5"), conical stump -rooted.
Generally good core and flesh color. Moderate skin texture.
Usually shorter than Nantes but
foliage size is between Berlicum and Autumn King. Used widely
for canning, freezing and
dehydrating. Processed where a multipurpose carrot is needed for
slicing and dicing. Not generally used for fresh market.
Kuroda (approximately 110 days): Also referred to as "Asian
carrot". Generally
thick-shouldered, short to medium length, tapered but with blunt
tip, light orange to well-colored,
mild flavor but a considerable range of flavor, shape, color and
uniformity is common.
Autumn King (approximately 100 days): Roots are very large (ave.
10-12"), tapering, usually with broad shoulders. Core and flesh color are generally inferior. Skin
texture is rough. Late ripening and heavy yielding. Foliage and crowns are large and vigorous.
Strong flavored. Grown mainly for certain fresh markets.
High Vitamin A: Have 2-4 times higher beta-carotene, the
precursor of vitamin A, than standard carrots.
Other "Nutritionally Enhanced or "Unusually Pigmented": High levels of xanthophyll, anthocyanin, lycopene, and other antioxidant
pigments.
Baby carrot: These are
primarily "manufactured" (cut and peeled) from undersized carrots, or pieces of carrots intended
for other packs. Because of the large demand for this product, growers are planting high density
carrots for this purpose also. True whole "baby" carrots are more costly and difficult to
produce, harvest, and handle, however. See also section on "baby-whole carrots" below.
VARIETIES FOR PROCESSING
A recent survey of the carrot industry in the Columbia Basin
area of Washington indicated a wide range of carrot varieties being used. Varieties
used by growers who grew for the fresh market and also slicing carrots for processing included:
Apache, Caro-Best, Caropak, Gold Pride, Legend, Plato, and Orlando Gold. Baby carrot producers
use varieties such as Caropak, Primecut 59, and Sugarsnax 54.
Processors specify varieties. Some that have been grown are:
Baby whole - Amsterdam types: Amca, Amstel, Colora, Caropak, Indu, Minicore, Verona. For trial: Babette.
Baby cut (manufactured from Imperator types) - Caropak, Gold Pride, HM 4302, HM 4303, Primecut 59, and Sugarsnax 54. For trial: Candy Stick, HMX 6320, Morecuts, SCR 7248, Tripleplay 58.
Cut and Peel: For trial: The summer 1999 issue of Carrot Country
magazine features new varieties developed by a specialty carrot seed company, Polonica Seed. They have released
'Grower's Choice', described as the top-ranked variety in the USDA 1994-95 trials in California. Also KXPC-054 ('Morecuts')
and KXPC-055 ('Sweetcuts'), both ranked in the top five carrot types in the USDA trials the last two years, as well
as the top spots in 1966. Also KXPC-060, winner of the 1998 USDA Wisconsin muck soil trials for
cut and peel carrots.
Slicing - Apache, Caropak, Favor, Gold Pride, Nevis, Orlando Gold, Pak Mor, Pioneer, Plato, Primecut 59,
Six-Pak, Sugarsnax 54, Tripleplay 58. For trial: Bolero, CXC 2670, Merida, Mokum, Parano, Stylus, Touchon.
Dicing - Carson, Cascade, Danvers 126, Early Gold, Red Cored Chantenay, Royal Chantenay, and the hybrid Spartan Bonus 80.
For trial: Cascade, Carson, Chantenay Supreme F1 (dicer,
combines Chantenay and Danvers qualities), Cumberland, Eclipse, Sytan (see note below).
Multipurpose - Danvers 126, Gold King, Royal Chantenay, and
the hybrids Chantenay Supreme, and Spartan Bonus 80. For trial: Cheyenne,
Enterprise, Indiana, Newport, Pacific Gold, Presto, and Vita Sweet 691, 711, and 781.
VARIETIES FOR FRESH MARKET
Bunching - Nantes types: Bolero, Favor, Gold Pride, Ingot, Merida, Parano, Pioneer,
Primo F1, Napa, Nevis, Royal Nantes, Scarlet Nantes, Tip Top. For trial:
Cheyenne, Enterprise, Indiana, Newport, Newton, Pacific Gold, Presto, Vita Sweet 691, 711, and 781.
Imperator types: Apollo, Discovery, Flare, Imperator 58, Neptune.
Cello-pack: Apache, Bolero, Caropak (also popular for "baby"
carrots), Choctaw, Favor, Gold Pride, Napa, Nevis, Orlando Gold, Pak Mor, SixPak II.
For trial: Ivanhoe, Merida, Newton, Parano.
High Vitamin A): A-Plus; BetaIII (an Imperator type with 2-4 times higher beta-carotene, the
precursor of vitamin A); HCM; Ingot (long Nantes type, also with high beta-carotene, suggested for
bunching); Progenitor.
Other Nutritionally Enhanced and Unusually Pigmented: For trial: Beta Sweet (purple-orange), Dragon (purple), Lobbericher (yellow),
Lubianna (yellow), Nutri-Red (red), Sweet Sunshine (yellow), Yellowstone (yellow).
Baby carrot: Cello bags of fresh baby carrots are now very popular. These are primarily "manufactured"
(cut and peeled) from undersized or pieces of carrots intended for other packs. However,
because of the large demand for this product, growers are also planting high density carrots for
this purpose. True whole "baby" carrots are more costly and difficult to produce, harvest and
handle. See varieties of Baby Whole Carrots, above. More information on baby carrots and cello-pack carrots can be
found in Carrot Country Magazine, Fall, 1999.
Novelty: Thumbelina, Orbit (round "Parisian market" types).
Washington State University research reports are available for annual trials conducted in the Columbia Basin Production area.
For a complete copy of the research results contact:
Dr. Erik Sorensen
WSU Cooperative Extension, Franklin Co.
Courthouse
Pasco, WA 99301.
Note: Research reported in England indicates that the Nantes type variety Tip Top (Breeders
Seed Ltd.) and the Danvers type variety Sytan (Clause Ltd.) showed resistance to carrot rust fly.
SOILS
Deep well drained, sandy loam or much soils of pH 5.5 (6.5 in eastern Oregon) to 7.0 are
desirable. A chisel plow is recommended to work these soils to a depth of 12 to 15 inches for
good root penetration. Soils may be bedded to obtain optimum drainage and maximum root length
and smoothness. The sandy soils in the Hermiston area and Columbia Basin, combined
with their long growing season, and a harvest period relatively free from rain, are particularly
suited to high carrot yields and quality.
SEED TREATMENT
Use high quality size-graded and
fungicide-treated seed for optimum uniformity and performance.
Pelletized carrot seed is commonly used with precision spacing,
and has been found to be useful in
improving size uniformity. A number of pelletizing materials are
available, differing in weight, cost and response to soil moisture. Primed and coated seed is
also becoming popular. Consult your seed dealer about the availability of primed seed.
ROW COVERS
For premium fresh market carrots, research in England and at OSU has shown that fresh market
carrots respond favorably to the use of floating row covers. These covers are available in widths
of up to 40 feet, and lengths suitable for most fields, allowing the covering of about 1 acre per
roll. The use of these field covers immediately after seeding greatly reduces crusting and
maximizes stand establishment. Researchers in England have demonstrated that the covers can be
applied immediately after seeding and should be removed at about the 7th true leaf to maximize
earliness and yield without generating too much top growth. If covers are used, temperature
under the covers should be monitored, and covers removed when temperatures are likely to
exceed 85-90 F for several consecutive days.
OSU researchers have demonstrated that herbicides can be applied through the row covers if
necessary, and that herbicides applied prior to covering are as effective as if applied without the
covers.
SEEDING AND ROW ARRANGEMENT
First fields of processing carrots may be seeded as early as mid-March and the last about the first
of July. Carrots for fresh market may be seeded as late as July 20.
Generally 2 to 4 lb seed are needed per acre for fresh market
or slicing carrots for processing. For dicing carrots for processing, 1 to 2 lb seed are needed.
Carrot seed numbers about 370,000/lb.
Research from Chrisseed in Washington State indicates that
carrots grown for the cut-and-peel market should be planted at between 1.5 and 1.75
million seeds/acre. For the cello-pack market, seed rate should be about
1 million/acre. Foliar diseases may be aggravated at the higher
plant populations, and care should be exercised in the choice of
varieties when planting at these high populations to select those with
appropriate disease resistance and top characteristics.
Plant populations per lineal foot of bed containing 2 scatter rows (or 4-6 lines), should be 12-(24)
for dicing and 30-(40) for slicing or fresh market carrots.
Ideally, raised beds 4 to 6 inches high, on 40 to 42-inch
centers should be used. Two scatter rows, or two multiple-line sets of 2 or 3 lines each, are planted l2 to l4
inches apart per bed (depending on bed width). Seeds are placed 1.3 to 2 inches apart. The lines
of each set are spaced 1.5 to 2 inches apart. In some cases, beds 72 inches apart, with 54 inch
tops are used. In such configurations, 4 double or triple-line sets are planted across
the bed top. When triple line sets are used increase the distance between seeds in the center row. Wide
beds can only be used in conjunction with overhead irrigation.
Schematics of planting configurations described above:
_/|||---|||\___/|||---|||\__
2 rows of triple-line sets on
2 beds on 40-inch centers
__/|||--|||--|||--|||\__
4 rows of triple-line sets
on a 70-inch bed
Where overhead irrigation and 40 to 42-inch beds are used, and
where modified potato diggers are used for harvest, it may be better to place the line sets closer
together and further from the edge of the bed. This would reduce exposure of carrots in the outside
lines to sunlight as the edges of the beds erode, and reduce the necessity to cultivate between the
sets. The distance between the sets would be limited only by the distance needed between
planters as depicted below:
__/-|||-|||-\___/-|||-|||-\__
two rows of triple-line sets on
2 beds on 40 inch centers with
the sets placed closer together
Seeding with a precision seeder is recommended. Vacuum
seeders such as Stanhay or Gaspardo are becoming popular. The Stanhay belt planter has a special
shoe that plants 3 lines l.5 inches apart with each planter unit. The seed belt is punched to drop 7 to 8
seeds per foot of line in the two outside lines and 5 to 6 seeds per foot in the middle line. The
Stanhay vacuum planter also has the capability of planting 3 rows per planter unit. Each vacuum
plate meters seed to three separate lines. Lines are generally 1.5 to 2 inches apart and
seeds are dropped about 1.5 to 2 inches apart down the line, resulting in 4 to 6 seeds per foot of
seed-line for dicers and 6 to 8 plants for slicers. When triple line sets are used increase the
distance between seeds in the center row.
For non-bedded plantings use row spacings of l6 to 30 inches
apart and in-row stands of 10 to 20 plants per foot for dicing, or 20 to 30 plants per foot of row for
slicing (or fresh market) carrots. Use the lower plant populations when planting single rows and the
higher populations when planting scatter-rows or multiple sets of rows.
The use of raised beds has been reported to reduce the incidence of cavity spot, a complex
disorder recently attributed to Pythium violae and possibly Pythium ultimum. Outbreaks of these
fungi are favored by excessive soil moisture and temperatures of 61-72 F. Alfalfa, wheat,
cauliflower, broccoli, celery, cucumber, sugarbeet and watermelon also serve as hosts and so
should not precede carrot, or be in rotation with it. Long rotations (3-4 years), good water
management and prompt harvest are other suggested cultural control measures.
BABY-WHOLE CARROTS
Although most "baby" carrots are manufactured from standard
carrots as noted above, whole baby carrots may also be produced. To obtain a uniform size and
shape of whole baby carrots, seed should be sown at high density and distributed evenly in
wide bands or solid beds. The seed need not be pelleted but should be size-graded by the supplier.
Pelleting would be too costly at the plant populations required.
A precision seeder is not necessary for planting this type
of carrot. Adequate results have been obtained by planting with a plate seeder at the rate of 80 to 100
seeds per square foot. At these spacings as much as 20 lb seed per acre may be required.
Planting multiple, staggered, scatter-rows 4 inches apart results in a "solid" stand when a
4-inch scatter shoe is used. Staggered planters capable of planting multiple lines per unit (such as
Beck or Stanhay) might also be used. Thirty or more lines would be needed on a 54 inch wide bed. Beds are
generally 72 inches center-to-center.
Schematic of spacing for whole baby carrots as described above:
/||||||||||||\___/||||||||||||\
Lines placed 1.5-2 inches apart on
beds that are 72 inches "on center"
FERTILIZER
A soil test is the most accurate guide to fertilizer
requirements.
Good management practices are essential if optimum
fertilizer responses are to be realized. These
practices include use of recommended varieties, selection of
adapted soils, weed control, disease
and insect control, good seed bed preparation, proper seeding
methods, and timely harvest.
Because of the influence of soil type, climatic conditions,
and other cultural practices, crop
responses from fertilizer may not always by accurately predicted.
Soil test results, field
experience, and knowledge of specific crop requirements help
determine the nutrients needed and the rate of application.
Fertilizer applications for carrots should insure adequate
levels of all nutrients. Optimum
fertilization is intended to produce top quality and yield
commensurate with maximum returns.
For the early crop, band half the nitrogen and all the
phosphate and disk-in the potash. Side dress
the balance of the nitrogen after the crop is 6 to 8 inches tall.
For the later plantings one may broadcast all the fertilizer before seeding.
Western Oregon
The following recommendations are general guidelines for Western Oregon
muck soils:
Nitrogen: 50-100 (N) lb/acre
Phosphate: 100-160 (P205) lb/acre
Potash: 80-150 (K20) lb/acre
Sulfur: 30-50 (S) lb/acre
For the early crop, band half the nitrogen and all the phosphate
and disc in the potash. Side dress the balance of the N after the crop is 6 to 8 inches tall. For the
later plantings one may broadcast all the fertilizer before seeding.
The following are recommendations for Western Oregon mineral
soils:
For carrots, fertilizer materials are usually broadcast and worked into
the seed bed ahead of planting.
The suggested fertilizer applications are based on a 24-inch row spacing and
20 to 25 plants per linear foot of row.
Recommended soil sampling procedures should be followed in order to
estimate fertilizer needs. The Oregon State University cooperative extension agent in your county can
provide you with soil sampling instructions and soil sample bags and information sheets.
Nitrogen (N)
Rates of 75 to 120 lb of N/A are suggested. Broadcast N before planting
or part of the N can be applied as an early season top dressing. Excess N can cause splitting.
Phosphorus (P)
Carrots require adequate available P for satisfactory growth. Broadcast
P and work into the seed bed before planting.
If the soil test* Apply this amount of
for P reads (ppm): of phosphate (P2O5) (lb/A):
0 - 20 120 - 150
20 - 50 90 - 120
50 - 75 60 - 90
Over 75 None
*Assumes extraction procedures similar to those used by the OSU Central
Analytical Laboratory. Specific information on soil test procedures is
available from the Dept. of Crop and Soil Science.
Potassium (K)
For optimum growth carrots require a good supply of available K.
Broadcast K and work into the seed bed before planting.
If the soil test* Apply this amount of
for K reads (ppm): potassium (K2O) (lb/A):
0 - 75 120 - 180
75 - 150 90 - 120
150 - 225 60 - 90
Over 225 None
*Assumes extraction procedures similar to those used by the OSU Central
Analytical Laboratory. Specific information on soil test procedures is
available from the Dept. of Crop and Soil Science.
Sulfur (S)
Include 15-20 lb S/A in the fertilizer program for carrots. 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 available 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 and ammonium sulfate have an acidifying effect on soil.
The S requirements of carrots can be provided by:
- The application of 15-20 lb S/A in the form of sulfate before planting.
- Applying 30-40 lb S/A as fine ground (finer than 40 mesh)
elemental S the preceding year.
- Applying coarser ground elemental S at higher rates and less frequently.
Magnesium (Mg)
To date, there have been no observed indications of yield response from
applications of Mg to carrots in the Willamette Valley. Trial applications of 10 to 15 lb Mg/A are
suggested with soil test values below 1 meq Mg/100g soil.
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
seed bed at least several weeks in advance of seeding and preferably the preceding year.
Boron (B)
Carrots require an adequate supply of B. Apply 2 to 4 lb B/A (broadcast
and disk in before planting).Do not exceed the recommended rate of
application. Excess B can be toxic to carrots.
Boron should be broadcast uniformly on the soil. Never place boron in a
side-band close to the seed at planting.
Other Nutrients
Response of carrots to nutrients other than those discussed in this
guide have not been observed in western Oregon.
Lime
At present, lime is not generally recommended for carrots, as carrots in
western Oregon are commonly grown on sandy river bottom soils which usually have adequate levels
of calcium and magnesium.
A lime application is suggested where the soil pH is below 5.6.
If the SMP Buffer* Apply this amount
test for lime reads: of lime (T/A):
Below 5.2 4 - 5
5.2 - 5.6 3 - 4
5.5 - 5.9 2 - 3
5.9 - 6.2 1 - 2
Over 6.2 0
*Assumes extraction procedures similar to those used by the OSU Central
Analytical Laboratory. Specific information on soil test procedures is
available from the Dept. of Crop and Soil Science. The liming rate is based
on 100-score lime.
Lime should be mixed into the seed bed 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 SMP buffer value (over 6.2) and a
low pH (below 5.3). This condition can be caused by the application of acidifying fertilizer. In
this case the low pH value is temporary and the pH of the soil will increase as the fertilizer
completes its reaction with the soil. This temporary "active" acidity from fertilizer is encountered
following recent applications of most nitrogen fertilizer materials. Acidifying fertilizers
also have a long term acidifying effect on soil that is cumulative and leads to lower SMP
buffer readings.
Sandy soils to which fertilizers have not been recently applied
sometimes record low pH and high
SMP buffer values. In such cases, a light application of lime (1 to 2 tons/A)
should suffice to neutralize soil acidity.
For acid soils low in Mg (less than 0.5 meq Mg/100g soil) one ton/A of
dolomite lime can be used as a Mg source. Dolomite and ground lime stone have about the same ability to
neutralize soil acidity.
These recommendations are based on experiments conducted by Horticulture
and Crop and Soil Science departments researchers of the OSU Agricultural Experiment Station
and Extension Service as quoted form the OSU Fertilizer Guide FG 29.
Eastern Oregon
For Eastern Oregon mineral soils, the following are general
guidelines:
NPK
Nitrogen: 80-l50 (N) lb/acre
Phosphate: 60-150 (P205) lb/acre
Potassium: 60-180 (K20) lb/acre
See above under Western Oregon for other nutrients.
IRRIGATION
Carrots grown in western Oregon may require 14 to 16 inches of water
depending on seasonal variation, variety, and length of season.
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.
Carrot Water Use:
The following crop water use and irrigation management information is from the OSU Carrot Irrigation Guide
developed by M. Hess, J. Smesrud, and John Selker (Dept. of Bioresource Engineering) and N.S. Mansour:
Total Seasonal Evapotranspiration (inches) 21.7
Peak Evapotranspiration Rate (inches/day) 0.20
Maximum Allowable Depletion (percent) 50
Critical Moisture Deficit Period: seedling emergence, root expansion
In eastern Oregon, on sandy soils, 20-25 inches of water may
be needed. 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. A total of 20-30 inches of water may
be needed depending on planting and harvest dates.
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.
Moisture management in carrots is especially important during stand
establishment and during root expansion. Since small carrot seeds are
unable to emerge when surface crusting occurs and can be burnt off if
surface temperatures are too high, irrigation during the pre-emergence
period revolves around maintaining a moist, cool, loose soil surface.
This often requires frequent, light irrigation. Conversely, deep, excessive
irrigation during this period promotes problems with damping off of
emerging seedlings. In the remainder of the season, available soil moisture
should be depleted by no more than 50 percent. However, maintenance of
excessively moist soil may cause anaerobic soil conditions that can kill
the root growing point, resulting in misshapen carrots at harvest. As carrot
roots develop most of their size in the last half of their growth period,
irrigation is especially critical during this time. Water deficit during
this period will have the greatest negative impact on yields. A balance
must be struck, however, between maintaining adequate moisture while
minimizing wetness in the canopy that promotes the common fungal diseases
alternaria and cercospora. During the last half of the growing period,
irrigate only early in the day to allow for rapid canopy drying whenever
possible. Soils should also be allowed to dry to 50 percent of available
soil moisture during harvest to prevent excessive cracking and damage to
roots during harvest.
On most soils, weekly irrigation during the peak is adequate, however with sandy and sandy loam
soils, irrigation may be required as frequently as every three to four days.
The peak water use for carrots is approximately 0.20 and 0.17 inches per
day for April and May plantings respectively. On most soils, weekly
irrigation during the peak is adequate, however with sandy and sandy loam
soils, irrigation may be required as frequently as every three to four days.
References
1. Sanders, D.C. 1993. Vegetable Crop Irrigation, Leaflet No: 33-E (North
Carolina State University, Raleigh).
HARVESTING AND HANDLING
The University of California-Davis has a file on Minimal
Processing of Fresh Vegetables that discusses film wrapping and other topics.
Early fresh market carrots are harvested from early July to September. Late market carrots are
harvested into December. Market carrots must be over 5 inches long and between 3/4 and 1.5 inches in diameter. Carrots harvested and handled in hot weather are more likely to decay, and
care should be exercised in handling to prevent wilting.
Processing carrots may be harvested from the first of August to the end
of November. The prime harvest period is from the end of August to October 25. For late harvest,
carrot fields are limited to well-drained river bottom soils, even so, harvest schedules are often
disrupted by the weather. This is the main reason considerable acreage of late carrots has shifted to
the lower Columbia Basin sandy soil areas.
Average yields of fresh market and processing carrots combined were reported to be about 500
cwt/acre for 1990, through 1992 in the Pacific Northwest where most of the acreage is for
processing. For the same period, California carrot yields (which are mostly for fresh market)
averaged about 300 cwt/acre.
Fresh market carrots are washed, sorted, and packed in one or two pound plastic bags packaged
48 1-lb. bags, or 24 2-lb bags per carton; or loose in 50-lb mesh or plastic sacks.
Processing carrots may be harvested from the mid July to the
end of December.
Generally, custom-built, coulter pick-up, or modified potato harvesters,
rather than the belt pick-up Scott-Viner harvesters are used in the harvest of carrots for
processing. Scott-Viner types are generally used in harvesting carrots for fresh market or where tops
are expected to be suitable. Although carrots can be harvested several ways, single or multiple-row harvesters can be custom built by
Krier Engineering, 4774 Morrow Rd., Modesto, CA. Contact Mr. Alex Krier, 800-344-3218, for more information.
Other custom-built carrot harvesters, as featured in the summer,1999 issue of Carrot Country,
are available from:
- Amac, Inc., a Dutch company represented by KPR Inc., POB 608, 375 West Ave. D, Wendell, ID 83355-0608, Phone 208-536-6601, FAX 208-536-6695, E-mail info@KprIncorp.com, Internet www.KprIncorp.com
- Asa-Lift, a Danish company represented by Miller Farms, Hancock, WI, Phone 715-249-5160, FAX 715-249-5860, Email MillerFM@uniontel.net
- Everett Bros. Engineering Ltd., a British company. USA Tel/FAX 407-396-7515, Email sales@everettbros.btinternet.com, Internet www.everett-bros-eng.com
- Univerco Hydraulique (1978) Inc., a Canadian company. 713 Rte. 219, Napierville, PQ, J0J 1L0, Canada. Phone 800-663-8423, FAX 514-245-0068.
Carrots are processed immediately after harvest, and not
stored. Most are scalped (tops
removed) just prior to digging. A reduction in yield of about
15-20% occurs when carrots are
field scalped. Scalped carrots, and those with inadequate, or
frozen tops are harvested with a
coulter pick-up or a modified potato harvester. Carrots with
intact tops are harvested with a belt
pick-up harvester that lifts carrots by their foliage and allows
tops to be removed in the same operation.
For budgeting purposes, assumptions for processed carrot
yields are reported in the
Enterprise Budget section below.
PACKAGING
Fresh market carrots are washed, sorted, and packed in one or two-pound plastic bags packaged
48 1-lb bags, or 24 2-lb bags per carton; or loose in 50-pound mesh or plastic sacks at a packing
house.
STORAGE (Quoted or modified from USDA Ag. Handbook 66 and other sources)
Research in Michigan evaluating carrots that have been
crowned or not, washed or not and stored
in a plastic lined bin or unlined bin found that carrots stored
best when untopped, unwashed and
stored in plastic lined bins. Ideal storage is at 32 F and 99 %
relative humidity. Carrots stored in
unlined bins can lose 6% to 10% of their weight. Topping carrots
and washing them also
increased losses from decay. The worst treatment was topping,
washing and storing carrots in unlined bins.
Carrots for processing are not normally stored. When
storing, store carrots at 32 F and relative
humidity of 98 to 100 %. Carrots for processing may be given a
pre-storage dip treatment in a
0.1 % solution of sodium o-phenylphenate (SOPP) to effectively
reduce storage decay. The solution is not rinsed off after treatment.
Mature carrots are well adapted for storage and are stored
in large quantities during the fall and
winter for both the fresh market and processing. Careful
handling during and after harvest to
avoid bruising, cutting and breakage will help ensure successful
storage.
Mature topped carrots can be stored 7 to 9 months at 32 to
34 F with a very high relative
humidity, 98 to 100 %. However, even under these optimum
conditions 10 to 20 % of the carrots
may show some decay after 7 months. Under commonly found
commercial conditions (32 to 40
F) with 90 to 95 % relative humidity, 5 to 6 months storage is a
more realistic expectation.
Prompt cooling to 40 F or below after harvest is essential for
extended storage. Poorly
precooled roots decay more rapidly.
Carrots lose moisture readily and wilting results. Humidity
should be kept high. Carrots stored at
98 to 100 % relative humidity develop less decay, lose less
moisture, and remain crisper than
those stored at 90 to 95 % relative humidity. A temperature of
31 to 34 F is essential if decay
and sprouting are to be minimized. With storage at 40 to 50 F,
considerable decay and sprouting
may develop within 1 to 3 months.
Pre-storage washing of carrots may be desirable if they are
harvested under wet conditions. Many
potential decay-causing organisms are removed by washing. Also,
clean, washed carrots allow
freer air circulation. Air circulation between crates of pallet
boxes in which carrots are stored is
desirable to remove respiratory heat, maintain uniform
temperatures, and help
prevent condensation. An air velocity of about 14 to 20 ft/min is
adequate at low storage temperatures.
Bitterness in carrots, which may develop in storage, is due
to abnormal metabolism caused by
ethylene. This gas is given off by apples, pears, and certain
other fruits and vegetables and from
decaying tissues. Bitterness can be prevented by storing carrots
away from such products. Also,
development of bitterness can largely be avoided by
low-temperature storage, as it minimizes
ethylene production. Some surface browning or oxidative
discoloration often develops in stored carrots.
The highest freezing point for carrots is 29.5 F. Severe
injury in carrots immediately after
freezing is identified by lengthwise cracking and by blistering
caused by the formation of ice
crystals immediately beneath the surface. After thawing, a
darkened and water-soaked skin is
observed, and the carrots are soft and flabby. Use of controlled
atmospheres to extend storage of
carrots has not been promising. Atmospheres containing 5 to 10 %
carbon dioxide with reduced
oxygen concentrations of 2.5 to 6 % caused a marked increase in
mold growth and rotting over
that of carrots stored in air.
The most important decays of carrots in storage are gray
mold rot (Botrytis), watery soft rot
(Sclerotinia), crater rot (Rhizoctonia), fusarium
rot, rhizopus soft rot, bacterial soft rot, black rot
(Stemphylium), and sour rot (Geotrichum). Spoilage
losses will be minimized if the following
precautions are observed: Use new or disinfected storage
containers, handle carefully to prevent
injuries, pre-cool carrots, maintain them at a temperature near
32 F and avoid temperature fluctuations.
ENTERPRISE BUDGETS
The following information has been quoted from Oregon State University
Extension publication EM 8379, April 1988, which gives costs and return estimates for carrots grown
for processing in western Oregon. The publication should be consulted for the major assumptions
and operations used in constructing this information. This budget is intended to be used as
a guide in estimating actual costs and does not represent any particular farm.
Budget: Total variable costs for western Oregon carrots were estimated
at $423.91 and total fixed costs at $225.26 per acre, resulting in $679.17 total cost of production
per acre. The break-even price needed to cover variable costs was $14.13 per ton, and the
break-even price needed to cover all costs was $22.63 per ton, based on an estimated yield of
30 tons per acre.
The following information has been quoted from Oregon State
University Extension publications
EM 8459, March 1991 which gives costs and return estimates for
slicer carrots grown for
processing in eastern Oregon. The publication should be
consulted for the major assumptions and
operations used in constructing this information. This budget is
intended to be used as a guide in
estimating actual costs and does not represent any particular
farm.
Budget: Total variable costs for eastern Oregon were
estimated at $1001.23 and total fixed costs
at $341.21 per acre, resulting in $1,342.44 per acre total cost
of production.
The break-even price needed to cover variable costs was $40.04 per ton, and the
break-even price needed to
cover all costs was $53.69 per ton, based on an estimated yield
of 25 tons of non-scalped slicer
carrots per acre. Note: Non-scalped dicer carrot yields are
estimated at 35 tons per acre.
The following information has been quoted from the 1994
Washington State University
publication EB1504 for carrots produced in the Columbia Basin.
The publication should be
consulted for the major assumptions and operations used in
constructing this information. This
budget is intended to be used as a guide in estimating actual
costs and does not represent any
particular farm.
For Chantenay carrots, the budget indicates a total variable
cost of $1,140; total cash cost of
$1,452; total cash cost and depreciation of $1513; and a total
cost of $1,686.
The break-even price based on total costs is $42.15 per ton assuming 40 tons per
acre.
For Imperator carrots the budget indicates a total variable
cost of $1,405; total cash cost of
$1,716; total cash cost and depreciation of $17,70; and a total
cost of $1,965. The break-even
price based on total costs is $72.78 per ton assuming 27 tons per
acre.
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