Institute of Food and Agricultural Sciences
VEGETABLE PEST AND DISEASE
March 9, 2001
The warm dry weather that had persisted through much of February ended with the passage of a cold front across S Florida on March 4, which dropped daytime temperatures back into the low 70’s and nighttime lows into the upper 30’s and low 40’s. The front dropped about an inch of rain across most of the area giving some temporary relief from the long-standing drought. In a number of locations, this was the first significant rainfall in over 140 days. The FAWN weather station in Immokalee recorded 1.08 inches of precipitation.
Although warm temperatures at the beginning of the period averaged several degrees above normal which favored crop growth and development, cold wind associated with the cold front resulted in some sand blasting on young plantings and leaf damage to sensitive crops.
Planting in SW Florida is slowing seasonally. Most crops are in fair to good condition although growers are experiencing a higher than average grade out resulting from the cold damage experienced in January. The threat of cold weather is delaying the planting of spring crops in some northern Peninsula and Panhandle areas. Vegetables available include tomatoes, Chinese cabbage, peppers, strawberries, potatoes, snap beans, sweet corn, squash, cucumbers, eggplant, and specialty crops.
The National Weather Service in Miami forecast
is calling for increasing cloudiness over the next 24 hours with a 30 percent
of showers likely. Skies will clear as the front passes through.
Humidity will remain low and daytime temperatures should reach seasonable
norms in the low 80’s over the next few days increasing the need for irrigation.
IMMOKALEE Weather Summary:
|Date||Air Temp o F||Rainfall||Hours Below Certain Temperature (hours)|
|Min||Max||(inches)||40 o F||45o F||50o F||55o F||60°F||65°F||70°F||75°F|
Water restrictions imposed on November 29th, by the South Florida Water Management District remain in place and have been extended to east coast production areas. Restrictions vary by area. More detailed information about water-use restrictions is available on the District's web site at http://www.sfwmd.gov. Maps of the affected areas are also on the web site under "water shortage."
Phase 2 restrictions for water use, are now in effect for South Florida. This includes: Palm Beach, Monroe, Miami-Dade, Broward, Collier, Hendry, Lee, and parts of St. Lucie, Glades, Charlotte, and Okeechobee counties. Agricultural users dependent on Lake Okeechobee and the Caloosahatchee River remain under Phase 3 restrictions.
A number of respondents continue to report salted related problems and salt damage in plantings. In some instances salt damage can be traced to poor water management practices. Over irrigation can result in excessive solubilization of fertilizer salts, which may accumulate around plants. A number of growers have noted an increase in fusarium crown rot following salt injury. There have also been indications of rising salt levels in well water being pumped in coastal areas.
Thrips populations have increased dramatically across southwest Florida. Thrips are being widely reported on pepper and tomato. Populations have reached high levels in some fields. Respondents indicate that they are primarily seeing Florida flower thrips (Frankliniella bispinosa), although there have been a few isolated reports of melon thrips (Thrips palmae) showing up in a few places
Growers are advised to be alert for spider mites. Several respondents have reported problems with spider mites in eggplants and they are widespread in cucurbits as well. Recent field surveys have indicated high populations of mites on nightshade along ditch banks and field margins. Growers should be sure to scout stands of nightshade adjoining plantings, as this is a potential source of infestation and may help them circumvent possible problems. Given projections for continued dry conditions, spider mites will remain a threat to a variety of crops.
Broadmites are being widely reported in pepper and have been seen on eggplant and potato as well.
Leafminers are still going strong on a variety of crops with pressure fluctuating rapidly depending on location. Growers are reporting good control with Agrimek, Trigard and Spintor.
Pepper weevils are widely present and all reports indicate that populations are increasing. Several growers report serious losses from weevils especially in hot pepper varieties. Some growers have terminated older plantings were weevils had become unmanageable. Several growers have indicated obtaining satisfactory results in controlling weevils with either Capture or cryolite. All currently labeled materials are difficult to work into an IPM program once plantings begin to be harvested due to the 7 day PHI in force for all of them.
Worm activity is relatively light. There have been a few reports of southern army worm and tomato fruit worms popping up here and there. There have been a few isolated reports of low numbers of pinworms beginning to show up on tomato as well as some pickleworm on squash. Low levels of diamondback moths are being seen in brassicas. Apparently materials being targeted at leafminer are taking care of any potential worm problems.
Fairly high aphid populations are being seen in some potato fields. Some respondents have noted the scattered problems with aphids on peppers and cucurbits as well.
Some respondents are have reported finding fairly high whitefly populations in some isolated hotspots, but for the most indications are that populations remain at fairly low levels.
Several respondents have reported a significant increase in the incidence of tomato yellow leaf curl with some fields exhibiting 2 – 3 % infection rates. Even higher incidence of the disease has been observed in some fields that have been turned over to pin hookers. Given the potential ability of whiteflies to transmit the disease rapidly under optimal conditions to new plantings, growers should be alert for whitefly buildup and take measures to control them.
Sanitation is important, as is the control of the whitefly vector. Admire (imidicloprid) has shown excellent results in controlling whiteflies in tomato. Later in the season, alternative materials may be needed as Admire wears off. Infected plants should be rouged on identification. Crops in fields that have been harvested should be cleaned up as soon as possible to prevent the carry over of insect populations and disease inoculum.
There have been several reports of late blight on tomato in the western part of the five county area. Late blight has also been reported from on tomato in central Florida. Several people have inquired about the current status of Tattoo for use on tomatoes – at this time Tattoo has been withdrawn from the market and is not labeled for use on tomato.
A number of reports are indicating increased incidence of powdery mildew on squash. Incidence is moderate in some older fields. Weather forecasts for this spring suggest that powdery mildew may be a major concern this season.
Fusarium crown rot is still causing problems on tomato is some locations.
Use of disease resistant plants may provide growers with an option in the control of Fusarium crown rot.
BHN Seed has incorporated Fusarium crown rot resistance into their BHN 273 and BHN 336 varieties as well as their BHN 250, BHN 348 and BHN 477 varieties. For the moment, these are the only Fusarium crown rot resistant tomato hybrids available commercially, but other companies expect to have commercial varieties available soon. Three new Fusarium crown rot tomato hybrids were officially released for trial at the BHN Seed Fall field day on Dec. 14, 2000. These are BHN X585, BHN X586 and BHN X587.
If you would like more information on BHN Fusarium crown rot resistant tomato hybrids, contact BHN Product Development Manager - Ted Angell at 1(800) 606-0163 or firstname.lastname@example.org.
There have been several reports of angular leaf spot showing up on watermelon transplants.
Downy mildew is present on squash in several locations. There have also been a few isolated reports of downy mildew on watermelon.
Target spot is present at low levels in some locations.
Several respondents indicate observing early blight in both tomato and potato fields.
Bacterial leaf spot is present on tomato in some places. Incidence is low and occurrence is spotty.
Pest and Disease Detection
The most critical part of any management program is detecting and identifying problems before they have a chance to cause serious injury. For insects and mites, this can be done by inspecting plants on a regular basis and/or using traps, sweep nets, or shaking to detect flying insects.
Different types of traps are available for different target pests. Yellow sticky traps to may be used to detect winged aphids, thrips, and other pests, and. Pheromone traps that lure the males of specific pest species may be used in some field-grown vegetable crops; pheromone traps may be used to monitor pinworm populations in tomato fields, and are also used to monitor armyworm and tomato fruit worm populations.
Traps are usually placed just above the top of the crop canopy. The number of traps to use will depend upon your objectives and ability to inspect them. Traps should be inspected at least once per week, and counts or estimates made of pest numbers. Number the traps and keep records of trap locations and insect infestations. Once trapped, the pest insects must be identified. Recognition of these pests may take some training and a 10 or 15X hand lens for magnification, but it is very important to learn the general shape, size, and colors of the different pest groups. There are publications available that can help with the identification task.
Plant inspection or scouting is more important than traps for most crops. Inspect plants in all areas of the field looking underneath leaves near the top, middle and lower parts of plants. The same hand lens used for trap inspection can be used for plant inspection. Keep records of the type of pests found, the number of plants infested, and the severity of infestation. The Florida Tomato Scouting Guide is an excellent reference and contains a sample of a general scouting form. It can be seen on-line at HTTP://FTSG.IFAS.UFL.EDU/
Disease Control - General Principles
For a vegetable plant to become diseased, several conditions must be present: a susceptible host plant, a pathogenic organism, a method of distributing the organism and the proper environment for the organism to exist, enter the plant and thrive. When all these conditions are met at the same time, infection can occur, and a disease agent can become established.
The choice of disease-control measures must be based on accurate knowledge of the disease, its life cycle and the time of infection, as well as the part of the plant involved, the method of agent distribution and certain economic considerations.
Effective control methods include:
· Resistance: Many vegetable varieties are resistant to certain diseases. Use them whenever possible.
· Avoidance: Avoid introducing plant pathogens into the field. Use certified, disease-free seeds and transplants. Do not transport soils or tools from diseased areas to disease-free areas. Rotate crops to disease-free fields to avoid buildup of pathogens in the field.
· Eradication: The removal or plow down of diseased plants from the field, if practical, can help prevent the spread of some diseases to healthy plants.
· Sanitation: Removal or plow down of old plant parts, weeds and trash is important to eliminate inoculum for the spread of the disease and new places for its development.
· Pesticides: Approved disease-control pesticides should be applied, following label directions, for specific diseases.
· Applications should be directed at the plant parts attacked and must be applied at the proper time.
· Insect and weed control: Many disease organisms persist in weed hosts or are spread by insects. Effective control of these pests also is an important part of a good disease control program.
In order to initiate timely disease-control practices, crops should be routinely inspected for developing diseases. Growers should consider using integrated pest management (IPM) systems where appropriate.
FDACS is currently seeking a Section 18 label for Actara in Florida for use on peppers for the control of pepper weevil. Experimental results from trials conducted here in SW Florida by Dr Phil Stansly have indicated efficacy in the control of pepper weevil.
Growers who have experienced difficulties controlling pepper weevils with Vydate and who feel they need a more efficacious product are invited to communicate with the State Department of Agriculture and express their interest regarding their support for this Emergency (Section 18) label.
They should address their concerns to Mr. Charlie Clark at DACS and send a copy to Mike Aerts with FFVA.
Florida Department of Agriculture and Consumer
Attn. Mr. Charlie Clark
Pesticide Registration Section
3125 Connor Blvd.
Building # 6
Tallahassee, FL 32399-1650
Florida Fruit & Vegetable Association
Attn: Dr. Mike Aerts
4401 E. Colonial Ave.
Orlando, FL 32814
Letters should indicate that growers are having difficulty controlling pepper weevil with available materials.
Other points that might be included in your letter would include the following:
- the need to use the maximum rate and the
maximum number of applications to achieve control of weevils,
- old standbys are losing their efficacy against pepper weevils,
- the adverse effect of alternative materials on beneficial insects, and
- the fact the need for more sprays raises production costs.
Photo Gallery of Foliar Diseases on Cucurbits – this is site hosted by NC State has good photos of various foliar disease on cucurbits that will help you more easily recognize symptoms in the field. Set your browser to http://www.ces.ncsu.edu/depts/pp/cucurbit/disease/Image.html
Field Identification of Foliar Diseases - This complimentary site describes techniques by which growers or scouts using a 10x to 20x hand lens can make a tentative diagnosis of selected cucurbit diseases based on symptoms and fungal structures, if present. Go to http://www.ces.ncsu.edu/depts/pp/cucurbit/disease/lensID.htm
Up Coming Meetings:
March 13, 2001
Vegetable Growers Meeting
Identification, Sampling and Management of Nematodes
Hendry County Extension Auditorium
1085 Pratt Boulevard
For information contact 863-674-4092
March 27-28, 2001
Pesticide Applicator License Training and Examinations
Hendry County Extension Office
1085 Pratt Boulevard
March 27 AM - CORE Class
March 27 PM – Private Ag or Commercial/Public Row Crop category
March 28 AM – Commercial/Public Tree Crops category
March 28 PM - – Commercial/Public Aquatic category
There will be a $5 registration fee for each day’s program.
For registration information contact 863-674-4092
March 17-19, 2001
United 2001 Annual Conference & Trade Show
This is a great opportunity to meet with your
colleagues and counterparts in the vegetable industry from around the world!
Highlights include a comprehensive educational program including produce
technology, food safety, packaging, and commodity specific workshops. Vegetable
growers, shipper, packers and others in the vegetable industry can take
advantage of special discount registration rates by calling Gene McAvoy
at the Hendry County Extension Office at 863-674-4092 or Claire E. Kratch
at the United Fresh Fruit and Vegetable Association
April 22-26, 2001
85th Annual Meeting of the Potato Association of America (PAA 2001)
St. Augustine, Florida.
Hosted by the University of Florida/IFAS Hastings Research and Education Center, the conference will provide a forum for the presentation of new scientific information, conduct business of the association and facilitate fellowship among colleagues. The conference theme is Potato Plant Health into the New Millennium. Three days of stimulating paper sessions will be kicked off with a dynamic symposium entitled, "Impact of New and Emerging Diseases and Technologies on Potato Seed Certification" co-sponsored by the Certification and Pathology Sections of the PAA. Emphasis will be on challenging soil-borne diseases.
Oral and poster abstracts are being accepted through January 10, 2001. For more information visit the conference website: http://www.ifas.ufl.edu/~conferweb/paa/ or contact the University of Florida, IFAS Office of Conferences by phone (352) 392-5930 or by fax (352) 392-9734, or by Email: email@example.com
August 3, 2001
Florida Certified Crop Advisor Exam
South Florida Community College
Avon Park, Florida
Call FFAA at (863) 293-4827 for registration information.
Gordon Smith to retire as Editor Emeritus of Citrus & Vegetable Magazine.
Gordon has been a long time supporter of agriculture and has been a regular feature in Citrus and Vegetable Magazine over the years. You are cordially invited to a reception honoring Gordon Smith, retiring Editor Emeritus of Citrus & Vegetable Magazine.
Date: March 30, 2001
Location: Citrus Research and Education Center, Lake Alfred, Florida
Time: 1 - 3p.m.
Please RSVP before March 28, 2001
Contact Sandi at 800-362-1571.
Hope to see you there.
Burn Ban Begins - Florida Agriculture Commissioner Terry L. Rhodes issued an emergency declaration banning all outdoor burning in 39 of the state's 67 counties as a result of the lingering drought and wildfire threat. It prohibits every kind of outdoor burning -- except cooking in barbecue grills in yards or in public facilities - in counties stretching from Gainesville to the southern end of the state.
"The threat to human life and property is real, and it increases every day we go without significant rainfall," Rhodes said. "And unfortunately, the long-range weather forecast promises little relief until at least late spring, when June rainfalls begin." The burning ban will remain in effect until conditions ease, she said.
The counties affected by the ban are: Alachua, Brevard, Broward, Charlotte, Citrus, Collier, Dade, Desoto, Duval, Flagler, Gilchrist, Glades, Hardee, Hendry, Hernando, Highlands, Hillsborough, Indian River, Lake, Lee, Levy, Manatee, Marion, Martin, Monroe, Okeechobee, Orange, Osceola, Palm Beach, Pasco, Pinellas, Polk, Putnam, St Johns, St. Lucie, Sarasota, Seminole, Sumter and Volusia.
Counties in North Florida and the Panhandle are not subject to the burning ban because conditions are not as extreme there, although any outdoor wild land burning request, or request to burn vegetative land clearing debris, in those 28 counties must be approved by a local Division of Forestry office before a burn can take place, Rhodes said. This is the second state-burning ban in the last two years. Last May, the Department of Agriculture and Consumer Services imposed a burning ban throughout Florida on May 17.
The drought index - a measurement of the amount of moisture in the ground - is alarmingly high and climbing, Rhodes said. Ranging from 0 to 800 with zero being flood conditions and 800 desert-like, 35 counties in Central and South Florida have drought indexes in excess of 600. Normally, drought indexes that high do not occur until April or May. Since January 1, Florida has experienced 1,411 wildfires that have burned about 93,000 acres. Up to a quarter of them are believed to have been deliberately set and have been the subject of arson investigations by Rhodes' Office of Agricultural Law Enforcement.
Rhodes' office maintains an arson hotline -- 1 800 342-5869 -- which provides rewards of up to $5,000 for information leading to the arrest and conviction of arsonists.
Note: Be aware - Growers in southwest Florida have already received citations for inadvertently violating the ban. – Gene
FEDERAL RELIEF AVAILABLE FOR FARMERS
The U.S. Department of Agriculture announced last Sunday that farmers in 38 Florida counties are eligible for federal aid for crop damage totaling $179 million from recent freezes and flooding. The federal financial assistance will help farmers apply for low-interest emergency loan assistance from the Farm Service Agency. The size of the loans will depend on the extent of losses, security available, repayment ability and other eligibility requirements. Farmers in all Central Florida’s counties are eligible. Governor Bush requested the declaration last month after preliminary estimates showed freeze and flooding losses of $121.3 million for Florida’s vegetable growers, $47.5 million for fern growers and $10.2 million for the tropical fish industry.
For more information, visit the State of Florida Division of Emergency Management web site, www.floridadisaster.org, or contact Joe Myers, Director at the State of Florida Division of Emergency Management office by phone, 904-413-9969, or email, Joe.Myers@dca.state.fl.us.
The Benefits of Growing Older:
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.
Extension Agent II
Vegetable/Ornamental Horticulture 863-674-4092 phone
Hendry County Extension Office 863-860-8811 mobile
PO Box 68 863-674-4097 fax
LaBelle, FL 33975 firstname.lastname@example.org
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