Pest Management Guidelines - Vegetables
Pest Management Guidelines
A Cornell Cooperative Extension Publication

  
Cornell Guide for Pest Management of Vegetables

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Chapter 12 Asparagus

Chapter 18    Eggplant


Contents

18.1 Recommended Varieties. 180

18.2 Planting Methods. 180

18.3 Fertility. 181

18.4 Harvesting. 181

18.5 Disease Management 182

18.5.1 Fruit rot, primarily caused by Anthracnose, Colletotrichum coccodes, and Alternaria early blight, Alternaria solani and A. alternata. 182

18.5.2 Phytophthora crown or collar rot 183

18.5.3 Verticillium wilt, Verticillium albo-atrum and V. dahliae  183

18.6 Insect Management 184

18.6.1 Flea beetles, primarily the eggplant flea beetle, Epitrix fuscula; potato flea beetle, Epitrix cucumeris; and tobacco flea beetle, Epitrix hirtipennis. 184

18.6.2 Colorado potato beetle (CPB), Leptinotarsa decemlineata  184

18.6.3 Aphids, primarily the green peach aphid, Myzus persicae  186

18.6.4 Two-spotted spider mite, Tetranychus urticae. 187

18.7 Weed Management 187

18.8 References. 189

 

 

18.1 Recommended Varieties

 

Black Magic (purple black, oval

Dusky (purple black, pear oval)

Special Hibush (purple black, pear oval)

Classic (purple, elongated oval)

Kiko (purple, elongated oval)

Ichiban (purple, slender oriental type)

Little Fingers (purple, slender oriental type)

Rosita (rose pink, elongated oval)

Neon (rose pink, pear oval)

Ghostbuster (white, oval)

18.2 Planting Methods

 

This crop can produce fairly good yields in warm regions of New York, particularly during summers with higher than average temperatures. Eggplant is a moderately deep-rooted, indeterminate, shrubby or bushy plant, and many varieties are self-fertile.

 

Eggplant grows best between 75° and 85°F. Eggplant is very sensitive to frost and requires a warm, long, growing season. The use of plastic mulch often improves yields. Well-drained, deep, sandy loams are ideal for eggplant because it is a heavy feeder.

 

Set plants into the field after danger of frost is past and daily average temperatures are between 65° and 70°F. The usual planting dates in New York are May 20 to June 10.


 

Table 18.2.1 Recommended spacing.                   

Row (in feet)

In-row (in inches)

4-5

18-24

18.3 Fertility

 

Maintain a pH of 6.0 to 6.5. See Tables 18.3.1 and 18.3.2 below for the recommended rates of nitrogen, phosphorus, and potassium.

 

18.4 Harvesting

 

Harvest when the fruit is firm, fully formed, glistening, and the seeds and pulp are white. When the fruit is past prime, it becomes dull, and the seeds turn brown. Cut with a sharp knife or shears. Frequent picking will help ensure higher yields. The skin is tender and easily bruised or punctured, so it should be handled with care.

 

Store at 50° to 54°F and 90 to 95 percent relative humidity. Young immature fruit may be susceptible to chilling injury at 50°F. Storage life is about one week, but older, mature fruit harvested during cooler weather can store for two weeks or more at 50°F.


 


 

Table 18.3.1 Recommended nutrients based on soil tests for transplants in bare ground.

If using plastic mulch without fertigtion, broadcast and incorporate all fertilizer before laying plastic mulch.

N pounds/acre

P2O5 pounds/acre

 

K2O pounds/acre

Comments

 

Soil Phosphorus Level

 

Soil Potassium Level

 

 

low

med.

high

 

low

med.

high

 

130

150

100

50

 

150

100

50

Total recommended

 

 

 

 

 

 

 

 

 

40

100

50

0

 

100

50

0

Broadcast and disk-in.

40

50

50

50

 

50

50

50

Apply in bands at planting or shortly after and cultivate.

50

0

0

0

 

0

0

0

Apply three weeks after planting.

 

Table 18.3.2 Recommended nutrients based on soil tests for transplants in plastic mulch, trickle irrigation and fertigation.

N pounds/acre

P2O5 pounds/acre

 

K2O pounds/acre

Comments

 

Soil Phosphorus Level

 

Soil Potassium Level

 

 

low

med.

high

 

low

med.

high

 

120

150

100

60

 

150

100

60

Total recommended

 

 

 

 

 

 

 

 

 

40

90

40

0

 

90

40

0

Broadcast and disk-in.

20

20

20

20

 

20

20

20

Apply 1 week after transplanting and every3-4 weeks.

 


18.5 Disease Management

18.5.1 Fruit rot, primarily caused by Anthracnose, Colletotrichum coccodes, and Alternaria early blight, Alternaria solani and A. alternata

Time for concern: During fruit development

 

Key characteristics:

Management Option

Recommendation

 

Scouting/thresholds

Begin sprays as first fruit ripens and continue on a seven to ten day interval.

 

Resistant varieties, crop rotation, site selection seed selection/treatment, postharvest, sanitation

These are not currently viable management options

 

Compound(s)

 

 

 

 

 

Common name

Rate/A

PHI

REI

Field

 

 

Trade name

Product

(days)

(hours)

Use EIQ

Comments

azoxystrobin

 

 

 

 

 

 

Amistar 80 WDG

2-5 oz

0

4

2-4

Begin application of Amistar (Group 11) before disease develops.

copper compounds

 

 

 

 

 

Champ F or OLF

1.3 pt

0

12/24 (see label)

19

Label varies with manufacturer and formulation.

maneb

 

 

 

 

 

Maneb 75DF              0.75 lb/lb

1.5-2 lb

5

24

12-16

 

 

Manex                          4 lb/gal

1.2-1.6 qt

5

24

19-25

 

pyraclostrobin

 

 

 

 

 

 

Cabrio EG

8-12 oz

0

12

3-5

Do not make more than 2 sequential applications (Group 11) before alternating to a labeled fungicide with a different mode of action.

 

 

 

 


18.5.2 Phytophthora crown or collar rot

Time for concern: Mid-season

 

Key characteristics: This disease causes collar rot, stem canker, and fruit rot. See Reference 1.

Management Option

Recommendation

 

Raised beds

For collar rot, plant onto raised beds.

 

Scouting/thresholds, resistant varieties, crop rotation, site selection, seed selection/ treatment, postharvest, sanitation

These are not currently viable management options

 

Compound(s)

 

 

 

 

 

Common name

Rate/A

PHI

REI

Field

 

 

Trade name

Product

(days)

(hours)

Use EIQ

Comments

dimethomorph

 

 

 

 

 

 

Acrobat 50WP, Forum SC

6.4 oz,    6.0 oz

0

12

5

4

Acrobat or Forum (Group 15) must be tank-mixed with a fungicide labeled for disease control but not with mefenoxam if it shows reduced sensitivtiy to Phytophthora.

mefenoxam

 

 

 

 

 

Ridomil Gold EC or OLF

1 pt

7

48

15

Broadcast. Must be applied to the soil before the plants are infected to obtain satisfactory control. After the initial application, two supplemental post-directed applications may be made at 30 day intervals.

 

 

 

18.5.3 Verticillium wilt, Verticillium albo-atrum and V. dahliae

Time for concern:

 

Key characteristics: Yellow blotches on the lower leaves, often v-shaped, may be the first symptom, then brown vein, and finally dark brown, dead spots. Leaves may wilt, die, and drop-off. Fruits remain small, develop yellow shoulders, and may sunburn. Diagnosis involves making a vertical slice of the main stem near the soil line and observing a brown color in the tissues under the bark. This disease is more severe under cooler temperatures, 68° through 75°F.

Management Option

Recommendation

Scouting/thresholds

Record the severity and occurrence of Verticillium wilt. No thresholds are available.

Resistant varieties

Plant resistant varieties whenever possible. The following varieties reportedly maintain yields in infested fields: Black Pride, Classic, Early Bird, Elondo, Epic, Vernal, and Viserba.

Crop rotation

Plant in fields that are not heavily contaminated with the fungus. Practice a four to five year rotation with crops other than tomatoes, potatoes, peppers, strawberries, or any of the brambles.

Sanitation

Soil fumigation will provide some control by delaying symptom expression.

Site selection, seed selection/ treatment, postharvest

These are not currently viable management options

 


18.6 Insect Management

18.6.1 Flea beetles, primarily the eggplant flea beetle, Epitrix fuscula; potato flea beetle, Epitrix cucumeris; and tobacco flea beetle, Epitrix hirtipennis

Time for concern: Early stages of plant development

 

Key characteristics: The eggplant and potato flea beetles are black and about 1/16 inch long. The tobacco flea beetle is similar in size, yellowish brown in color, and has a dark band across its wings. Damage appears as small holes in the leaves caused by adults feeding. The larvae of all three species are thin, white worms from 1/8 to 1/3 inch long. Larvae feed on the roots of plants but do not cause serious injury. See www.nysaes.cornell.edu/ent/factsheets/.

Management Option

Recommendation

Scouting/thresholds

Scout for flea beetles after setting plants in the field. Pay close attention to field edges. Thresholds:

 

Height of plant (in inches)

Number of flea beetles (per plant)

 

<3

2

 

3-6

4

 

>6

8

 

Apply insecticides when thresholds are met. See Reference 2.

Natural enemies

The species and effectiveness of natural enemies are not known.

Resistant varieties

No resistant varieties are available.

Postharvest

Deep plowing after harvest may reduce overwintering populations.

Sanitation

Keep fields free of weeds

Crop rotation, Site selection, and Seed selection/treatment

These are not currently viable management options.

Compound(s)

 

 

 

 

 

 

Common name

Rate/A

PHI

REI

Field

 

 

 

Trade Name

Product

(days)

(hours)

Use EIQ

Comments

 

beta-cyfluthrin

 

 

 

 

 

 

 

*Baythroid XL                               1 lb/gal

2.8 fl oz

0

12

<1

 

 

bifenthrin

 

 

 

 

 

 

*Capture 2EC                2 lb/gal

2.1-6.4 fl oz

7

12

3-9

 

 

imidacloprid

 

 

 

 

 

 

*Admire Pro                   4.6 lbs/gal

7.0-10.5 fl oz

21

12

10-15

 

 

carbaryl

 

 

 

 

 

 

Sevin XLR Plus              4 lb/gal

1 qt

3

12

19

 

 

endosulfan

 

 

 

 

 

 

*Thionex 3 EC              3 lb/gal

1.3 qt

1

24

37

Do not make more than 2 applications per season.

 

lambda-cyhalothrin

 

 

 

 

 

 

 

*Warrior                       1 lb/gal

2.56-3.84 fl oz

5

24

<1-1

 

 

zeta-cypermethrin

 

 

 

 

 

 

*Mustang MAX             0.8 lb/gal

2.24-4 fl oz

1

12

<1

 

 

*Restricted use only.

 

 

 

 

 

 

 

18.6.2 Colorado potato beetle (CPB), Leptinotarsa decemlineata

Time for concern: Late April through harvest

 

Key characteristics: The adults have alternate black and yellowish orange stripes that run lengthwise on the wing covers, five of each color on each wing. The beetles are 3/8 inch long by 1/4 inch wide and convex in shape. The eggs are yellowish orange and deposited in clusters on the underside of leaves. Egg masses contain between 20 and 40 eggs. Larvae are small, humpbacked, and red with two rows of black spots on each side of their body. Both adults and larvae chew the foliage and may defoliate the plants. See Reference 4 or www.nysaes.cornell.edu/ent/factsheets/.

Management Option

Recommendation

Scouting/thresholds

Begin scouting early in the season. Make insecticide applications when the following thresholds are met:

 

Height of plant (in inches)

Number of CPB per plant

 

<6

2 small larvae or 1 large larvae

 

>6

4 small larvae or 2 large larvae

 

See Reference 2.

Resistance management

Given the phenomenal ability of the CPB to develop resistance to insecticides, a major goal in managing this pest is to delay the onset of resistance. One way to achieve this is to rotate insecticide applications among different insecticide classes. Insecticides are broken down into classes in Table 3.1 in the Insect Management Chapter. For more information about CPBs, see Section 23.6 in the Potato chapter.

Natural enemies

Numerous organisms exist in the field. Both parasitoids and predators are useful. Use Reference 3 or www.nysaes.cornell.edu/ent/biocontrol/ for identification of natural enemies.

Resistant varieties

No resistant varieties are available.

Crop rotation

One year rotation to small grains or corn can result in greater than 90 percent reduction of early-season, adult infestation.

Site selection

Eggplant fields should be a considerable distance from overwintering sites.

Seed selection/treatment, Postharvest, and Sanitation

These are not currently viable management options.

Compound(s)

 

 

 

 

 

 

Common name

Rate/A

PHI

REI

Field

 

 

 

Trade name

Product

(days)

(hours)

Use EIQ

Comments

 

abamectin

 

 

 

 

 

 

 

*Agri-Mek 0.15EC                                 0.15 lb/gal

8.0-16.0 fl oz

7

12

<1

 

 

acetamiprid

 

 

 

 

 

 

 

Assail 30SG                        0.3 lb/lb

1.5-2.5 oz

7

12

<1-1

 

 

beta-cyfluthrin

 

 

 

 

 

 

 

*Baythroid XL                               1 lb/gal

1.6-2.8 fl oz

0

12

<1

 

 

bifenthrin

 

 

 

 

 

 

*Capture 2EC               2 lb/gal

2.1-6.4 fl oz

7

12

3-9

 

 

carbaryl

 

 

 

 

 

 

Sevin XLR Plus              4 lb/gal

1 qt

3

12

19

 

 

endosulfan

 

 

 

 

 

 

*Thionex 3 EC              3 lb/gal

1.3 qt

1

24

37

Do not make more than 2 applications per season.

 


 

Compound(s)

 

 

 

 

 

Common name

Rate/A

PHI

REI

Field

 

 

Trade name

Product

(days)

(hours)

Use EIQ

Comments

imidacloprid

 

 

 

 

 

*Admire Pro                  4.6 lbs/gal

7.0-10.5 fl oz

21

12

7-10

Not to be used as a foliar spray

 

*Provado 1.6F                          1.6 lb/gal

3.75 fl oz

0

12

1

 

oxamyl

 

 

 

 

 

†*Vydate L                2 lb/gal

1-2 qt

1

48

46-92

Not for use on Long Island. May leach into groundwater. Effective in combination with endosulfan against pyrethroid-resistant adults. Less toxic to predators than all other insecticides except Bt’s and endosulfan.

spinosad

 

 

 

 

 

Spintor 2SC                  2 lb/gal

3-6 oz

1

4

<1-2

Do not exceed 29 oz of product/acre/season.

 

Entrust                        0.8 lb/lb

1-2 oz

1

4

<1-2

Do not exceed 9 oz of product/acre/season. 

zeta-cypermethrin

 

 

 

 

 

*Mustang MAX                     0.8 lb/gal

2.24-4 fl oz

1

12

<1

 

*Restricted use only.

†) Not for use in Nassau/Suffolk Counties

 

 

 

 

18.6.3 Aphids, primarily the green peach aphid, Myzus persicae

Time for concern: June 15 through harvest

 

Key characteristics: Green peach adult aphids can be green, pink, red, or dark brown. They  range in length from about 1/32 to 1/16 inch in length. See www.nysaes.cornell.edu/ent/factsheets/.

Management Option

Recommendation

Scouting/thresholds

Examine plants at a minimum of ten randomly selected sites throughout the field. Treat when a localized infestation is found.

Natural enemies

Naturally occurring predators, parasitoids, and pathogens help suppress aphid infestations. Use Reference 3 or www.nysaes.cornell.edu/ent/biocontrol/ for identification of natural enemies. Increases in aphid infestations are sometimes associated with applications of insecticides that have killed natural enemies.

Note(s)

Carefully check transplants before planting for infestation. Aphid populations decline rapidly during periods of heavy rainfall.

Resistant varieties

No resistant varieties are available.

Postharvest

Crop debris should be destroyed as soon as possible after harvest.

Sanitation

Destroy weeds around the fields.

Crop rotation, Site selection, and Seed selection/treatment

These are not currently viable management options.


 

Compound(s)

 

 

 

 

 

Common name

Rate/A

PHI

REI

Field

 

 

Trade name

Product

(days)

(hours)

Use EIQ

Comments

acetamiprid

 

 

 

 

 

 

Assail 30SG                      0.3 lb/lb

2.0-4.0 oz

7

12

1-2

 

endosulfan

 

 

 

 

 

*Thionex 3 EC              3 lb/gal

1.3 qt

1

24

37

Do not make more than 2 applications per season.

imidacloprid

 

 

 

 

 

*Admire Pro                  4.6 lbs/gal

7.0-10.5 fl oz

21

12

7-10

Not for use as a foliar spray.

 

*Provado 1.6F              1.6 lb/gal

3.75 fl oz

0

12

1

 

methomyl

 

 

 

 

 

 

*Lannate LV                     2.4 lb/gal

0.75-3 pt

5

48

7-28

 

oxydemeton-methyl

 

 

 

 

 

*MSR

2 lb/gal

1 qt

7

48

38

Do not exceed 3 applications per season. Systemic activity within plant.

oxamyl

 

 

 

 

 

†*Vydate L                2 lb/gal

1-2 qt

1

48

46-92

Not for use on Long Island.  May leach into groundwater.

pymetrozine

 

 

 

 

 

Fulfill                        0.5lb/lb

2.75 oz

0

12

2

Apply when aphids first appear but before populations build to damaging levels.   Do not exceed 5.5 oz/A per season.  Allow 7 days between applications.

*Restricted use only.

† Not for use in Nassau/Suffolk Counties

 

 

18.6.4 Two-spotted spider mite, Tetranychus urticae

 

Time for concern:

 

Key characteristics: The adult mite is yellow to dark green with two or four black, dorsal spots. Heavy damage may cause leaves to drop. Hot, dry weather favors a spider mite outbreak. See Reference 2.

Management Option

Recommendation

 

Scouting/thresholds

Search leaves with a hand lens. Spray if populations are growing rapidly or if natural enemies are absent. See Reference 2.

 

Natural enemies

Minute pirate bugs, predatory thrips, and predatory mites help suppress spider mite infestations. See Reference 3 or www.nysaes.cornell.edu/ent/biocontrol/ for identification of natural enemies. Increases in spider mite populations are sometimes associated with applications of insecticides which have killed natural enemies.

 

Note(s)

Carefully check transplants before planting for infestation. Spider mite populations decline rapidly during periods of heavy rainfall or after overhead irrigation has been used.

 

Resistant varieties

No resistant varieties are available.

 

Sanitation

Destroy weeds around the field in the fall or early spring to reduce overwintering populations.

 

Crop rotation, Site selection, Seed selection/treatment, and Postharvest

These are not currently viable management options.

 

Compound(s)

 

 

 

 

 

Common name

Rate/A

PHI

REI

Field

 

 

Trade Name

Product

(days)

(hours)

Use EIQ

Comments

abamectin

 

 

 

 

 

 

*Agri-Mek 0.15EC                                 0.15 lb/gal

8.0-16.0 fl oz

7

12

<1

 

bifenazate

 

 

 

 

 

 

Acramite 50WS          0.5 lb/lb

0.75-1.0 lb

3

12

6-7

Limited to one application per season.

bifenthrin

 

 

 

 

 

 

*Capture 2EC                                  2 lb/gal

5.12 - 6.4 fl oz

7

12

7

 

fenbutatin-oxide

 

 

 

 

 

*Vendex 50WP         0.5 lb/lb

2-3 lb

3

48

28-41

 

oxydemeton-methyl

 

 

 

 

 

*MSR             

2 lb/gal

1 qt

7

48

38

Do not exceed 3 applications per season. Systemic activity within plant.

oxamyl

 

 

 

 

 

†*Vydate L               2 lb/gal

1-2 qt

1

48

46-92

Not for use in Nassau/Suffolk Counties. May leach into groundwater.

*Restricted use only.

† Not for use in Nassau/Suffolk Counties

 

 

 

18.7 Weed Management

Key characteristics: Weed fact sheets provide a good color reference for common weed identification. See Reference 5.  See Chapter 4 for information on scouting/thresholds, site selection, cultivation, and banding of herbicides

Compound(s)

 

 

 

 

 

Common name

Rate/A

PHI

REI

Field

 

 

Trade Name

Product

(days)

(hours)

Use EIQ

Comments

preplant incorporated or preemergence

bensulide (annual grasses, redroot pigweed, and common lambsquarters)

 

 Prefar 4-E                     4 lb/gal

5-6 qt

 

12

120-153

For transplants only. Preemergence application is most effective when coupled with irrigation. Crop rotation restrictions for nonlabeled crops are 120 days.

napropamide (annual grasses, redroot pigweed, and common lambsquarters)

 

Devrinol 50DF          0.5 lb/lb

2-4 lb

 

12

13-26

Preemergence application is most effective when coupled with irrigation. Crop rotation restriction for nonlabeled crops is 12 months.

pretransplant - postemergence to weeds

glyphosate (nonselective)

 

Roundup Weather Max or OLF                                  5.5 lb/gal

1-1.4 pt weeds < 6"

 

  1.4-2 pt weeds > 6"

14

4

8-11

 

 

11-15

Apply lower rate if weeds are less than 6” tall. Apply prior to transplanting and allow at least 3 days between application and planting.

preemergence or postemergence

halosulfuron (Preemergence applications:  galinsoga, lambsquarters, mustard/radish species, redroot pigweed, ragweed, velvetleaf.  Yellow nutsedge is suppressed but not controlled.  Postemergence applications:  yellow nutsedge, galinsoga, redroot pigweed, mustard/radish species, ragweed, velvetleaf)

 

Sandea

0.5-1 oz

30

12

<1

May be applied only to row middles.  No more than 2 oz/Acre may be applied per season. 


 

Compound(s)

 

 

 

 

 

Common name

Rate/A

PHI

REI

Field

 

 

Trade Name

Product

(days)

(hours)

Use EIQ

Comments

postemergence

clethodim (annual and perennial grasses)

 

*Select 2EC                   2 lb/gal

6 - 8 fl oz

20

24

2

For control of numerous annual and perennial grasses.  DO NOT apply more than 32 fl. oz. of Select 2EC (0.5 lb ai) per acre per season.   DO NOT apply more than 8 fl. oz. per application. Application on LONG ISLAND is restricted to no more than 16 fl. oz. of Select 2EC (0.25 lb ai) per acre per season.  Always use a crop oil concentrate at 1% V/V in the finished spray volume.

sethoxydim (annual grasses)

 

Poast                           1.5 lb/gal

1.0-1.5 pt

20

12

5-7

Apply when grasses are actively growing and not under stress. Apply with 2 pts of oil concentrate per acre.

postemergence - hooded row middle application

carfentrazone

 

 

 

 

 

 

Aim EW                        1.9 lb/gal

0.5-1.6        fl oz/ application

0

12

<1

May be used only as a hooded, row middle application.  Sprayers must be designed to prevent ANY contact with the crop and may not be operated at more than 5 MPH.  Special care must be taken when operating on uneven ground.  See product label for additional precautions.

*Restricted use only.

 

 

 

 

18.8 References

 

1 Zitter, T. A. 1989. Phytophthora blight of peppers and other vegetables, p. 736.20. In Vegetable Crops: Diseases of Peppers. New York State Agricultural Experiment Station, Geneva.

2 Foster, R., and B. Flood, eds. 1995. Vegetable Insect Management: With Emphasis on the Midwest. Meister, Willoughby, Ohio.

3 Hoffmann, M. P., and A. C. Frodsham. 1993. Natural Enemies of Vegetable Insect Pests. Cornell Cooperative Extension. 64 pp.

4 Muka, A. A., and M. Semel. 1983. Colorado potato beetle, p. 760.00. In Vegetable Crops: Insects of Solaneceous Crops. New York State Agricultural Experiment Station, Geneva.

5 Pennsylvania State University. 1987. Weed identification, pp. 1-32. Pennsylvania State University Cooperative Extension, University Park.


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