Cooperative Extension Service 
________________________________________________
Institute of Food and Agricultural Sciences
 

Hendry County Extension P. O. Box 68 LaBelle, Florida 33975-0068 Phone (941) 674-4092

SOUTHWEST FLORIDA
VEGETABLE PEST AND DISEASE
HOTLINE

January 22, 1999

Mild weather has prevailed across the area over the past two weeks.  Heavy dew accompanied by dense morning fog has been widespread particularly in the last week.  Overall, pest and disease activity has been rather quiet.

Reports of late blight on potato have been received from a number of locations around Immokalee. All samples diagnosed to date have been US 8, a fairly aggressive strain that infects predominately potato. Incidence is sporadic and infection levels are low to moderate. High innoculum loads observed on samples examined along with heavy dews and foggy conditions and rainy, windy conditions predicted over the weekend may create optimum conditions for the epidemic spread of this disease. Growers are advised to monitor this situation closely and apply protectant materials in advance of unfavorable weather conditions.  Some of the new fungicides with ďkick-backĒ activity have given good results.

Tomato yellow leaf curl virus is being reported widely across the area. In general, the incidence of infection is low (less than 1%) and confined to a few plants per field. In most instances the disease is being seen occurring on older plantings on shoots at the tops of the plants.  A few newly planted fields are showing much higher levels of diseased plants and infection appears to be originating in the plant house. In these cases, there appears to be fairly strong correlation with the geographical location from which transplants were obtained.   Growers would be well advised to source transplants from areas of the state with low incidence of TYLCV infection. Affected plants should be rogued-out upon identification. Use of imidacloprid to control white fly is strongly recommended.  As the crop matures and whiteflies become apparent growers should implement alternate control strategies. The major concern is carry-over to the spring crop.

Relatively high whitefly counts continue to be reported across the area on a number of crops.  This is particularly true on older plantings.  With the presence of TYLCV in SW Florida, this should be a concern to local growers.  Growers need to be especially diligent in cleaning up old crops promptly as whiteflies as well as leaf miners can build up rapidly in old unsprayed fields. Pepper weevils and aphid populations can also build up quickly in old pepper plantings.

Leaf miner numbers remain high but seem to have stabilized across the area.  A few reports indicate the movement of leaf miner from abandoned fields onto new plantings. Leaf miner is being seen widely in a number of crops and should remain active for the next few months.

Aphids have been observed in a number of areas primarily on cole crops, cucurbits, and pepper. Incidence is sporadic and counts generally low.

An increase in armyworm activity has been noted by a number of respondents from scattered locations across the region.  Sightings include beet, fall and southern armyworm depending on the location. Numbers and crop damage has been low.

The first report of diamond back moths on crucifers has come in from the eastern part of the region.  A few pinworms are also being seen in traps in the Devilís Garden area.

Target spot is widely present on tomato.  Damage is generally low to moderate and tends to be most severe in older crops in their second or third harvest where foliage is dense and harvesting has damaged plants and help spread the pathogens.

An increase in bacterial spot activity encouraged by heavy fog and dew has been reported from several locations on tomato and pepper.   Incidence is sporadic and infection levels are light to moderate in most cases. With the exception of bacteria and target spot, the incidence of foliar diseases on tomato and pepper has been relatively low.

Thrips numbers remain very low.  A few flights have been observed in East Naples and are reported to have bitten crews working in the fields.

Alternaria and downy mildew have been reported on cole crops in Devilís Garden.

A single report of spider mite on eggplant was received this reporting period.

FAWN Weather Data from SWFREC Station/Immokalee for December 1998.
 
 
Average
Average
Average
Average 
Average
Average
Total
Average
 Total
Total
 
Air
Air
Soil
Soil 
Solar
Wind
Rain
RH
Pan
Penman
 
Max
Min
Max
Min
Radiation
Run
 
Low
Evap.
ET
 
F
F
F
Langleys
Miles
Inches
 %
 Inches
Inches
1998
79
58 
77 
71
275 
63
1.55
56 
3.81
3.92
1997
75
56
76
71
246
80
5.50
57
3.68
3.58
1989-1997
76 
54 
75
67
229
75
1.87
55
3.33
3.59

Contributors include: Cathy Carabiner/Sieverts, Bruce Corbitt/West Coast, David Harloff/Pacific Tomato Growers, Fred Heald/Farmers Supply, Cecil Howell/H+R Farm, Leon Lucas/Glades Crop Care, Gene McAvoy/Hendry County Extension, Alice McGhee/Thomas Produce, Chuck Obern/C+B Farm, Wade Purvis/Silver Strand, Dr. Pam Roberts/SWFREC, Wes Roan/6 Lís, Harvey Rowe, Jay Shivler/F+F Ranch, Kevin Seitzinger/Gargulio, Dr. Phil Stansly/SWFREC and Dr. Charlie Vavrina/SWFREC.

The SW Florida Pest and Disease Hotline is compiled by Gene McAvoy and is issued on a biweekly basis by the Hendry County Cooperative Extension Office as a service to the vegetable industry.

Gene McAvoy
Extension Agent II
Vegetable/Ornamental Horticulture            941-674-4092 phone
Hendry County Extension Office                 941-860-8811 mobile
PO Box 68                                                    941-674-4097 fax
LaBelle, FL 33975                                 gmcavoy@gnv.ifas.ufl.edu

The Institute of Food and Agricultural Sciences is an Equal Employment Opportunity - Affirmative Action Employer authorized to provide research, educational
information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap or national origin.
COOPERATIVE EXTENSION WORK IN AGRICULTURE, FAMILY AND CONSUMER SCIENCES, SEA GRANT AND 4-H YOUTH, STATE OF FLORIDA, IFAS, UNIVERSITY OF FLORIDA, U.S. DEPARTMENT OF AGRICULTURE, AND BOARDS OF COUNTY COMMISSIONERS COOPERATING

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