Prepared: May, 2006
State rank: New Jersey ranks 4th nationally in kale production1
New Jersey's contribution to total US production: 7.6%1 Yearly fresh market production:Annual production costs:
Spring Crop: Including growing ($844.17), and
harvesting and marketing ($1,969.74) = $2,813.91/acre7
Fall Crop: Including growing ($961.99), and
harvesting and marketing ($1,953.13) = $2,915.12/acre7
Southern New Jersey (area south of Trenton)
Nearly all kale, Brassica oleracea var. acephala L.,
is grown in the southern half of southern New Jersey. The soils in this area are coastal plain, generally light soils ranging from sand to sandy loams, but areas of heavier, clay and silt loam soil do exist. Elevations are low with most of the area less than 200 feet in elevation. The warmest, seasonal temperatures occur in the extreme southern part of the state with the Salem County area being the warmest.
In New Jersey, kale is a cool season crop that is raised in the spring and fall. Fields are direct seeded into the field in a series of rows. In some situations, kale may be grown in frames and then transplanted to the field. Seeds that are not hot water-treated by the seedsman
should be soaked at 122oF (50oC) for 20 minutes. Since hot water treatments reduce germination
rates, an alternative is to treat with 1 sodium chlorite, 1 part lactic acid
and 18 parts water for 1 to 2 minutes followed by a thorough rinsing in running
water for 5 minutes. Either treatment
must then be followed by dusting with either Captan 50WP or Thiram 25wp at 1
level teaspoon per pound of seed (3 ounces per 100 pounds). Seeds are sown at a rate of 3 lbs/A in rows spaced 16 to 24 inches apart. Upon emergence, plants are thinned to
Spring seeding typically occurs around April 20th. Seeding for the fall harvest begins in Mid-July through late August. Kale can be harvested three ways: whole plant, bunched leaves, or "stripped" leaves. "Stripped" kale is pre-packaged for fresh market. In all methods, yellow or damaged leaves must be removed before packing.
In New Jersey, the primary insect pests of kale are: aphids, beet armyworm, black cutworm, cabbage looper, cabbage root maggot, corn earworm,
diamondback moth, flea beetles, harlequin bugs, imported cabbage worm and
thrips.
Aphids
Aphids, usually green peach aphid, feed on the plant sap and may cause plant stunting if large numbers exist. Feeding damage results in curled leaves and stunted plants. Aphids may further transmit viral diseases such as kale mosaic. In New Jersey, green peach aphids overwinter on hardwood
hosts such as peach, cherry and plum. Overwintering eggs hatch in spring into females that reproduce parthenogenetically. After one to two generations winged females migrate to alternative hosts such as kale where they spend the summer. In late summer and early fall temperatures and shortening day length trigger that development of a winged males and females that mate and move back to hardwood hosts. Once there, females lay eggs that remain on shoots until spring.
Threshold: Prior to
harvestable leaf maturity, treatment should begin when populations reach 1
aphid per 10 plants9. After head formation, kale should be treated
when aphid colonization begins
Beet armyworm
This is a migratory pest from the southern states that is found from mid to late summer in several vegetable crops in New Jersey. The armyworm caterpillar is a foliage
feeder capable of consuming large amounts of foliage. The fall planting of kale is the most susceptible to beet armyworm. The moths lay their eggs in the
hearts of the plants, with larvae feeding on
Threshold: Prior to harvestable leaf maturity, kale should be treated when populations have reached 1 larva per 50 plants9.
After head formation, kale can tolerate 1 larva per 100 plants.
Black Cutworm
Seedlings are the most
significantly impacted by cutworm attack10. Newly hatched larvae
feed on the leaves temporarily, but then drop to the soil surface and burrow
underground. The larvae emerge at night and feed on the kale plants. Cutworms damage kale by cutting the stem at,
or just below the soil surface.
Sometimes a cutworm will bore into a kale plant from below. Individual cutworms are capable of damaging
several plants in one evening and large populations can destroy entire fields.
When cutworms have been active, several wilted or collapsed plants in a row can
be observed. Recently tinned stands are
especially sensitive to cutworm attack.
Cabbage looper
Like other caterpillars these insects feed on the foliage and should be
considered one of the major pests of kale. Damage occurs mostly in late summer
and early fall. Cabbage loopers may be present at
harvest and therefore be a contaminant as well as their feces.
Threshold: Prior to
harvestable leaf maturity, kale should be treated when 10% of plants are
infested with any combination of caterpillars.
Cabbage root maggot
Cabbage root maggot larvae feed by
tunneling into the roots11. Young plants may be stunted or even
killed. Larval feeding can deform roots; sometimes the deformed roots are
mistaken for a disease called clubroot. A large
population of root maggots can potentially destroy a young crop.
Threshold: No thresholds are available.
Diamondback moth
Larvae attack all stages of plant growth,
however, damage is most significant during the seedling stage and at harvest10.
Larvae attack the growing points on young plants, stunting growth and
decreasing yield. The larvae will chew small holes, mostly on the underside of
mature leaves, on mature plants. The larvae of the diamondback moth penetrate
kale heads, damaging the head and feeding on the plant’s growing point. Kale damaged by diamondback larvae or
contaminated by the larvae is unmarketable.
Threshold: Prior to harvestable leaf maturity, kale should be treated when 10% of plants are infested with any combination of caterpillars.
Flea beetle
Flea beetles frequently attack leafy green vegetables. Eggs are laid on the soil surface and larvae feed on plant rootlets, seldom causing significant damage. The adults cause the shot hole feeding damage in leaves, which sometimes becomes extensive. Usually, only the smaller seedling plants are at risk from flea beetles and the most severe damage occurs on field borders or at the edge of plantings. Depending upon the species of flea beetle there may be multiple generations each year.
Threshold: Prior
to harvestable leaf maturity, kale should be treated when 50% of the plants
have beetles or a combination of beetles and fresh damage.
Harlequin bug
This pest has the ability to destroy the entire crop where it is not controlled12.
The harlequin bug injures the host plants by sucking the sap of the plants,
causing the plants to wilt, turn brown and die. A generation of the harlequin bug requires 50 to 80 days. The life cycle consists of three stages: egg, nymph and adult. Harlequin bugs pass the winter as adults and true hibernation is doubtful.
Threshold: No thresholds are available.
Imported Cabbageworm
Imported
cabbageworm larvae chew large, irregular-shaped holes into kale leaves10.
Young plants can be stunted or killed by the feeding action of larvae. Larvae
feed for 2 to 3 weeks and then attach themselves to the stem or leaf on the
plant or a near by object to pupate. The presence of the larvae, larvae frass
or pupae within the kale head or damage to the leaves will render the plant
unmarketable.
Threshold: Prior to
harvestable leaf maturity, kale should be treated when 10% of plants are
infested with any combination of caterpillars.
Thrips
Feeding
by thrips causes wrinkling and deformation of leaves, damages heads and
stunts growth10. Feeding also
causes brown scars on the leaves of kale.
Extreme damage causes leaves to dry and fall off the plant. Thrips feces (Black Dust), on leaves
distinguish this damage from windburn or sand burn. Thrips present in harvested kale are
considered a contaminant and leaves damaged by thrips feeding are not
marketable.
Threshold: No thresholds
are available.
Insecticides used in 2000 -- last year of available data 6, 7
Bacillus thuringiensis (BT)
• BT use was 24.33 lbs ai or about 6.84% of
all insecticides used.
• The preharvest interval for BT is 0 days
• The restricted entry interval for BT is 4 hours
Chlorpyrifos (Lorsban)
• Chlorpyifos use was 48.47 lbs ai or about 13.63% of all insecticides
used.
• The preharvest interval for chlorpyrifos is either at planting (15G) or 21 days (4EC, 50WP)
• The restricted entry interval for chlorpyrifos is 12 hours
Diazinon
•Diazinon use was 126.35 lbs ai or about 35.54% of all insecticides used.
• The preharvest interval for diazinon is 10 days
• The restricted entry interval for diazinon is either 12 or
24 hours depending on formulation
Dimethoate
• Dimethoate use was 47.44 lbs ai or
about 13.34% of all insecticides used.
• The preharvest interval for dimethoate is 14 days
• The restricted entry interval for dimethoate is 48 hours
Imidacloprid
•Imidacloprid use was 1.39 lbs ai or
about 0.39% of all insecticides used.
• The preharvest interval for imidacloprid is either 21 (Admire) or 7 (Provado) days
• The restricted entry interval for imidacloprid is 12 hours
Malathion
•Malathion use was 16.26 lbs ai or about 4.57% of all
insecticides used.
• The preharvest interval for malathion is 7 days
• The restricted entry interval for malathion is 12 hours
• Malathion is not recommended for use in New Jersey
Methomyl
• Methomyl use was 118.24 lbs ai lbs or about 33.26% of all insecticides.
• The preharvest interval for methomyl is 10 days
• The restricted entry interval for methomyl is 48 hours
Pyrethrin
• Pyrethrin use was 1.0 lbs ai or about
0.28% of all insecticides used.
• The preharvest interval for Pyrellin is 0 days
• The restricted entry interval for Pyrellin is 12 hours
• Pyrellin is not recommended for use in New Jersey
Rotenone
• Rotenone use was 1.68 lbs ai or about 0.47% of
all insecticides used.
• The preharvest interval for Pyrellin is 0 days
• The restricted entry interval for Pyrellin is 12 hours
• Pyrellin is not recommended for
use in New Jersey.
Spinosad (Spintor)
• Spinosad use was 5.25 lbs ai or about
1.48% of all insecticides used.
• The preharvest interval for spinosad is 1 days
• The restricted entry interval for spinosad is 4 hours
• Spinosad is used primarily for controlling imported cabbageworm,
cabbage looper, beet armyworm and thrips.
Tebufenizide (Confirm)
• Tebufenizide use was 6.92 lbs ai or about 1.95% of all insecticides used.
• The preharvest interval for tebufenizide is 7 days
• The restricted entry interval for tebufenizide is 4 hours
Aphids
Acetamiprid 0.8-1.2 oz 70WP/A G
Diazinon 1 pt 4EC/A R-NJ
Dimethoate 0.5-1 pt 4
EC/A R-NJ
Imidacloprid 10 - 24 fl
oz 2FS/A (soil)
Imidacloprid
3.75
fl oz 1.6F/A (foliar)
Oxydemeton-methyl 1 qt 2SC/A R
Pymetrozine 2.75 50W/A G
Beet Armyworm
Bacillus thuringiensis see
labeled rate on specific products G
Emamectin benzoate
– 2.4 – 2.8 fl oz 5SG/A R
Indoxacarb 3.5 fl oz/A G
Spinosad 1.5 – 6 oz 2SC/A G
Tebufenozide 6 - 8 fl oz 2F/A G
Black Cutworm
Bifenthrin 2.1 – 6.4
fl oz 2EC/A R
Carbaryl 20 –
40 lb 5% bait/A G
Chlorpyrifos 2
lb 50WP/A R
Cyfluthrin 0.8
- 1.6 fl oz 2E/A R
z-Cypermethrin
2.4 – 4.3 fl oz 2EC/A R
Diazinon 2 – 4
qt 4EC/A R-NJ
Cabbage Looper
Bacillus thuringiensis see
labeled rate on specific products G
Cyfluthrin 1.6
– 2.4 fl oz 2E/A R
z-Cypermethrin
3.4 – 4.3 fl oz 2EC/A R
Emamectin benzoate
– 2.4 – 2.8 fl oz 5SG/A R
Fenpropathrin
10.66 – 16 fl oz 2.4EC/A R
Indoxacarb 2.5 - 3.5 fl oz/A G
Methomyl 1.5 - 3 pt
Methoxyfenozide 4 – 8 fl oz 2F/A G
Spinosad 1.5 - 6 oz
2SC/A G
Tebufenozide 6 - 8 fl oz 2F/A G
Cabbage root maggot
Direct Seeded
Diazinon 1.5 fl oz
4EC/1,000 ft of row R-NJ
Chlorpyrifos 4.6 – 9.2 oz
15G/1,000 ft of row R
Diazinon 10.25 – 0.5 lb
50WP/50 gal R-NJ
Diazinon 0.25 – 0.5 pt
4EC/50 gal R-NJ
Chlorpyrifos 1.6 – 3.3 fl oz
4EC/1,000 ft of row R
Diamondback moth
Bacillus thuringiensis see
labeled rate on specific products G
Emamectin benzoate
– 2.4 – 2.8 fl oz 5SG/A R
Indoxacarb2.5 - 3.5 fl oz/A G
Spinosad 1.5 - 6 oz
2SC/A G
Flea Beetle
Bifenthrin 2.1 – 6.4
fl oz 2EC/A R
Carbaryl 0.67 –
1.25 lb 80S/A G
Cyfluthrin 2.4
– 3.2 fl oz 2E/A R
z-Cypermethrin
2.4 – 4.3 fl oz 2EC/A R
Endosulfan 1 –
1.33 qt 3EC/A R
Fenpropathrin
10.66 – 16 fl oz 2.4EC/A R
Imidacloprid
3.75 oz 1.6F G
Harlequin bugs
Bifenthrin 2.1 – 6.4
fl oz 2EC/A R
Carbaryl 0.67 –
1.25 lb 80S/A G
Cyfluthrin 2.4
– 3.2 fl oz 2E/A R
z-Cypermethrin
2.4 – 4.3 fl oz 2EC/A R
Endosulfan 1 –
1.33 qt 3EC/A R
Fenpropathrin
10.66 – 16 fl oz 2.4EC/A R
Imported cabbageworm
Bacillus thuringiensis see
labeled rate on specific products G
Chlorpyrifos 2
lb 50WP/A R
Cyfluthrin 1.6
– 2.4 fl oz 2E/A R
z-Cypermethrin
3.4 – 4.3 fl oz 2EC/A R
Emamectin benzoate
– 2.4 – 2.8 fl oz 5SG/A R
Fenpropathrin
10.66 – 16 fl oz 2.4EC/A R
Indoxacarb 2.5 -3.5 fl oz/A G
Methomyl 1.5 - 3 pt
Methoxyfenozide
4 – 8 fl oz 2F/A G
Spinosad 1.5 - 6 oz
2SC/A G
Tebufenozide 6 - 8 fl oz 2F/A G
Thrips
Bifenthrin 2.1 – 6.4
fl oz 2EC/A R
Cyfluthrin 0.8
– 1.6 fl oz 2E/A R
z-Cypermethrin
3.4 – 4.3 fl oz 2EC/A R
Spinosad 4 - 10 oz
2SC/A G
Chemical Use in IPM Programs
Kale is harvested for fresh market sales at farm markets and
supermarkets. Individual farmers are
responsible for maintaining the quality of the crop. The main emphasis is acceptable, marketable
produce that contains little leaf or head damage.
Chemical Use in Resistance Management
Producers are encouraged to rotate chemical classes of
insecticides when possible.
Alternatives
There is no current alternative to insecticide use.
Cultural Control Practices
A combination of the following cultural strategies can be used
to reduce insect problems in kale13:
Biological Controls
No current intentional uses of biological control are available.
Selective use of insecticides can benefit predator and parasitoid activity that
may help control aphids and other pest insects.
Post Harvest Control Practices
Growers are encouraged to till under crop residues immediately
after harvest. This enhances rapid breakdown of residues and mechanically
induces mortality to remaining insect crop pests.
All weeds are pests in kale, because they will compete with for
nutrients, water, and space. Generally, weeds are considered to be at threshold
when they are distributed at the rate of 1 weed per square yard. Weeds cause problems for fresh market kale
because workers must separate the weeds by hand before bunching.
Summer Annuals: All annuals and especially zero tolerance weeds including nightshades, morningglory, jimson weed, common cocklebur, and
chickweed.
Perennials: Zero tolerance weeds including Horsenettle,
yellow nutsedge, Canada thistle, common milkweed,
help dogbane, field bindweed, johnsongrass, bermudagrass, and quackgrass.
These weeds especially should not be allowed to become established because of
either intense competition with the crop or increasing difficulty of harvest.
Fall planted and Over-wintered crop
Winter Annuals: All winter annuals.
Summer Annuals: All summer annuals, and especially zero tolerance weeds including nightshades, morningglory, jimsonweed, and
common cocklebur.
Perennials: Zero tolerance weeds including Horsenettle, yellow nutsedge, Canada thistle, common milkweed, help dogbane, field bindweed, johnsongrass, bermudagrass, and quackgrass. These weeds especially should not be allowed to become established, because of either intense competition with the crop or increasing difficulty of harvest.
Chemical Controls
Herbicides used in 2000 – last year of available data7, 8
Bensulide (Prefar)
• Bensulide use was 15.28 lbs ai or about 12.68% of all herbicides used
in 2000.
• The restricted entry interval for bensulide is 12 hours
• Bensulide is applied as either a pre-plant or pre-emergent herbicide and has activity on several grass and broadleaved species.
DCPA (Dacthal)
• DCPA use was 84.44 lbs ai or about 70.06% of all herbicides used.
• The restricted entry interval for DCPA is 12 hours
• DCPA is applied as a pre-emergent herbicide and has activity on several grass and broadleaved species.
Trifluralin (Treflan)
• Treflan use was 20.8 lbs ai or about 17.26% of all herbicides
used.
• The restricted entry interval for trifluralin is 12 hours
• Trifluralin is applied as a pre-emergent herbicide that has activity on several grass and broadleaved species.
• Incorporate 2 to 3 inches into soil by double disking within 8 hours after application.
Current (2004) Pesticide Recommendations for Weed Pests, Product Rates Per Acre (G=general, R=restricted)6
Seeded
Trifluralin 1 – 1.5 pt 4E/A G
Transplanted
Trifluralin 1 – 2 pt 4E/A G
Preplant Incorporated
Bensulide 5 – 6 qt 4E/A G
Post Planting
DCPA 8 – 14 lb 75WP/A G
Chemical Use in IPM Programs
None.
Chemical Use in Resistance Management
Growers are urged to rotate chemical classes when spraying for
weeds.
Alternatives
Depending upon circumstances and the weeds involved, hand
weeding may be done to make sure that the weeds are removed.
Cultural Control Practices
Crop rotation is recommended to assist in weed management.
Biological Controls
None.
Post Harvest Control Practices
Tillage immediately after harvest is encouraged to reduce pest
populations. After the spring crop, any weeds left in fields when the kale is
harvested would remain as a cut stem.
Tilling of fields will destroy weeds before they have a chance to regrow and go to seed.
Alternaria
Alternaria leaf spot (Alternaria brassicae
and A. Brassicola)
forms round leaf spots that are typically tan to dark brown. Lesions are often
surrounded by yellow halos. Leaves with
2% affected surface area are unmarketable and should be trimmed or left in
fields during cutting.
Threshold: Presence of the disease.
Black Rot
Black rot, caused by Xanthomonas campestrispv.campestris, is
a common bacterial disease of kale that occurs in cool to moderate
temperatures. The bacterium is often
seed-borne and can also overwinter in plant debris. If soil-borne, the
bacterium can enter the leaves through hydrathodes
present at leaf margins. Black rot causes leaf veins to turn black and leaves
to turn yellow. Whole plant infections
will cause the plant to wilt. Infected
leaves are unmarketable and symptoms may develop after harvest.
Threshold: Presence of the disease.
Blackleg
The fungal disease Blackleg, Phoma lingam, prefers moist conditions and cooler temperatures. Black leg symptoms
begin as small necrotic spots on the leaves and stems of plants that enlarge in cool, moist conditions. Spots often
develop black fungal fruiting bodies (pycnidia) in
the center of lesions. Severe stem
infection often results in a dry, dark rot above the soil line, thus the black
leg name. The lesion can girdle the entire
stem, causing the plants to wilt and eventually die.
The fungus
survives in plant residue (crop and weeds) and on infested seed coats. Under
the right environmental conditions, overwintering
fungi produce spores that are spread to other plants by water, wind and
machinery. Seed-borne inoculum has been
shown to be important in disease development, seed infections greater than 1%
severe crop loses.
Threshold:Presence of the disease.
Clubroot
Clubroot is caused by the fungus Plasmodiophora brassicae. The pathogen can survive in the soil for
seven to ten years without the presence of a susceptible host. Susceptible crops or weeds (i.e. mustard
family) grown or present during this period may allow the disease to become
more prevalent. The movement of soil and
dead crop debris into uninfected areas may help move the fungus to new
locations. Resting spores are produced
in infected roots and released into the soil., thereby
allowing the fungus to survive for many years without the presence of a susceptible
host.
Initial symptoms include plant
decline (yellowing of leaves) and a tendency to wilt during hot days. Examination of the roots reveals swollen,
club-shaped roots instead of the normal fine network of roots. In severe cases, most roots will become
infected. The swollen roots decay and eventually disintegrate. Slightly
infected plants may show few symptoms above ground other than slow growth and
will have very small knots on roots; young infected plants may not show severe
enough symptoms to be detected until later in the production season.
Threshold: Presence of the disease.
Downy Mildew
Downy
mildew, caused by Peronospora parasitica, poses
the largest threat to kale production in New Jersey. Downy mildew thrives in cool, humid weather
that promotes spore (sporangia) formation and dispersal and subsequent plant
infection. Under favorable conditions, P. parasitica
can spread rapidly via wind and rain. Downy mildew can survive on infected seed
and be transported via infected transplants.
The development of gray-white fungi on the lower leaf surface is a sign of plant infection. Damage begins with chlorotic lesions that later turn purple and eventually brown and can damage to upper and lower leaf surfaces. Young leaves may dry and drop off; older leaves generally remain on the plant and often develop a papery texture. Severe infections can result in decreased photosynthesis, stunted plants and reduced yield. Downy mildew is a systemic disease that results in darkened areas and/or black streaks in the stem that makes the plant susceptible to secondary infections.
Threshold: Presence of the disease.
Damping off
Damping-off is caused by soil borne fungi (Pythium spp. or Rhizoctonia solani) that attack germinated seedlings prior to or just after emergence. Cool, wet weather promotes Pythium infections; whereas more warmer, moderate weather promotes Rhizoctonia infections. Poorly drained fields that have compacted soil and/or high green organic matter are ideal for allowing Damping-off infections to occur. Damage usually occurs at soil level, causing lesions in the stem tissue that becomes dark and withered eventually causing the seedling to collapse and die. Pythium
can also attack the seedling’s roots, causing them to turn brown and
rotten. After plants that have reached
the three to four leaf
susceptibility to fungal damping-off declines stage.
Threshold: No thresholds exist for this disease.
White Mold
White mold, caused by Sclerotinia sclerotiorum, causes damage ranging
from little to complete destruction of the plant. While some varieties are resistant, susceptible plants may develop wilts and/or rots. The pathogen can cause damage to both above-and below-ground parts. Infected plants are typically randomly distributed throughout the field. Infected plants
develop a dark green, greasy or water-soaked appearance. Stem lesions may become brown to bleached white in color. Under conditions of high
humidity, white fluffy mycelia develop into hard, black sclerotia. White mold sclerotia can persist in soils for several years. Sclerotia at or just below the soil surface can germinate to form very small, orange-colored, mushroom-like structures called apothecia that forcibly
discharge ascospores into the air. These spores can be carried for a mile or
more and if they come into contact with a susceptible plant, and moisture
levels and temperatures are correct, an infection can occur.
Threshold: Presence of the disease.
Yellows
Yellows is caused by Fusarium oxysporum f.
sp. conglutinans and is common as temperatures increase in the summer. Infected plants are not marketable due to the
wilting and yellowing of leaves. Kale is very susceptible to this disease and may die prior to obtaining marketable size.
Threshold: Presence of the disease.
Chemical Controls
Fungicides used in 2000 – last year of available data6, 7
Copper (Champ)
• Copper use was 3.21 lbs ai of copper or about 0.54% of all fungicides used.
• The preharvest interval for copper is 0 days
• The restricted entry interval for copper is 24 hours.
Fosetyl
• Fosetyl-aluminum use was about 78.99 lbs ai or about 13.39% of all fungicides used.
• The preharvest interval for fosetyl-aluminum is 3 days
• The restricted entry interval for tebufenizide
is either 12 or 24 hours
Quintozine (Terrachlor)
• Quintozine use was 507.82 lbs or about
86.07% of all fungicides applied on kale, was used.
• The preharvest interval for quintozine can be applied at planting.
• The restricted entry interval for quitozine
is 12 hours
Current (2004) Pesticide Recommendations for Disease Pests, Product Rates Per Acre and Use (G=general, R=restricted)6
Damping-Off
Black Rot and Blackleg
Use hot
water seed treatment and resistant varieties. Select site not previously
planted to crucifers for seedbeds. Rotate to allow 2 years between cole crop plantings for black rot control and 4 years
between cole crop plantings for blackleg control. For black rot control, fixed copper
sprays (1 pound active ingredient per acre) will aid in reducing spread of
black rot if treatments are started when disease first becomes evident
Clubroot
Use of irrigation water containing spores
of the fungus is one of the principal ways the disease is spread to new fields.
If clubroot occurs, take care to clean and disinfest
any equipment to be used in other fields to prevent spread. Adjust soil pH with
hydrated lime to as close to 7 as possible. Improve the drainage in the field
by making ditches, etc., and grow the crop on raised beds. Use Terraclor 75WP in one of the following ways. Do NOT use the
Terraclor 2EC formulation.
Downy Mildew and Alternaria
Use one of the following at the first sign
of disease and continue every 7 to 10 days:
For downy mildew only, use:
White Mold
The
following biological fungicide has been tested in some states; however, limited
information is available on effectiveness in the mid-Atlantic
region. Apply 3 to 4 months prior to the
onset of disease to allow the active agent to reduce inoculum levels of sclerotia in the soil.
Following application, incorporate to a depth of 1 to 2 inches but do
not plow before seeding cole crops to avoid untreated sclerotia
in lower soil layers from infesting the upper soil layer.
Contans--2-4 lb 5.3WG/A
Yellows (Fusarium)
Use resistant varieties. Where resistant
varieties are not available, practice long crop rotation intervals.
Chemical Use in IPM Programs
None.
Chemical Use in Resistance Management
Growers are urged to alternate fungicides with different modes-of-action (MOA) to reduce the chances for fungicide resistance development. Fungicides with the same MOA, and/or in the same FRAC grouping should not be applied consecutively and/or tank-mixed together.
Alternatives
There are some varieties with resistant to Black rot, Blackleg,
and Downy mildew.
Cultural Control Practices
Crop rotation is important
to prevent infection by yellows (3-4 years), downy mildew (2 years), Alternaria
(2 years) and black rot (2 years).
Cleaning and disinfecting equipment can assist in preventing clubroot infection in addition to avoiding contaminated
irrigation water and adjusting soil pH to 7.0.
Treatment of seed with hot water can prevent black rot and blackleg.
Increased row spacing and not entering wet fields helps prevent the spread of
black rot. Avoiding overhead irrigation
helps limit spread of Alternaria, black rot and downy mildew. Removal of weeds in the mustard family in and
around fields will remove potential reservoirs for many of the diseases that
affect kale.
Biological Controls
contans – for White mold
Post Harvest Control Practices
Farmers are encouraged to till under crop residues as soon as
harvest is completed to help break disease cycles.
Nematodes are not significant
pests of kale in New Jersey as most
kale is grown on sandy soils or light soils.
Chemical Controls
Nematicides used in 2000 – last year of available data6, 7
Metam-Sodium (Vapam)
• Metam-sodium use was 2.37 lbs.
• The preharvest interval for metam-sodium is applied prior to planting.
• The restricted entry interval for metam-sodium
is 48 hours
• Metam-sodium is applied as a general fumigant to control both diseases and nematodes.
Current (2004) Pesticide Recommendations for Disease Pests, Product Rates Per Acre and Use (G=general, R=restricted)6
FumigantsNon-fumigants
Nemacur 30 lb 15G/A R
Chemical Use in IPM Programs
None.
Chemical Use in Resistance Management
Growers are urged to use different chemical classes when
treating for nematodes.
Alternatives
None.
Cultural Control Practices
Preventing the spread of nematodes into uninfested fields can be prevented by good sanitation and removal of soil from tools and equipment prior to entering a new field. The use of nematode-free transplants can also help prevent spread. Green manures and soil amendments can be used to reduce population of some plant parasitic nematodes.
Biological Controls
None.
Post Harvest Control Practices
Crop rotation, allowing fields to remain fallow and the use of nematode suppressive cover crops can be effective in reducing nematode populations.
Post-emergent pesticides are applied by ground sprayers from
tractors or terragators (large 3 wheeled tractors
often equipped with boom sprayer arms) with enclosed cabs. Thus, exposure to
pesticides to applicators is minimal. IPM scouts and others visit fields about
twice a week starting at plant emergence and make recommendations for pest control
until harvest. Currently the longest
REIs exist for bifenthrin at 5 days; chlorothalonil, dimethoate, disulfoton,
emamectin benzoate and mefenoxam, methomyl at 48 hours; and acephate, Aliette, chlorpyrifos, l-cyhalothrin, diazinon,
fenproparthrin, maneb and permethrin at 24 hours; these REI’s do not negatively
impact the activities of IPM scouts. It is estimated that REIs greater than 7 days
would negatively inspection by scouts.
When destructive harvesting of kale is not employed, hand removal of
leaves of harvestable size could result in exposure to materials. No issues related to REI’s should occur when
the period of time necessary for re-growth of leaves is considered.