________________________________________________
Institute of Food and Agricultural Sciences
|
|
________________________________________________ Institute of Food and Agricultural Sciences |
Hendry County Cooperative Extension Office
PO Box 68
Labelle, Florida 33975
863-674-4092
Southwest Florida Vegetable Newsletter
July/August 2000
Calendar
Note from Gene
Integrated Pest Management and
Florida Tomatoes: A Success Story in Progress
Food Quality Protection Act - ReRegistration
New Tools
Worker Protection Standard
Transplant Age In Vegetables
FFVA’s Convention Golf Tournament
Malathion Risks Generally Acceptable
EPA Begins Assessment of WPS
EPA Issues Special Review Status Report
Pesticide Potpourri
Registration and Tolerance Actions
Hungry Americans
Worker Protection Standard Update
Tomato Varieties for Florida
Really Hot Pepper
Tips on Spraying
Microbial Insecticides
Instructions for Life
The Lighter
Side
September 6-8
The 25th Annual Joint Tomato Conference and Tomato Committee Meeting
Ritz Carlton, Naples, FL
Contact Dr. Charles Vavrina for program information @ 941-658-3400.
September 20-22
Florida Fruit and Vegetable Association Annual Meeting, Naples, FL
Contact 407-894-1351.
September 23-27
National Agricultural Plastics Congress
and the International Congress for Plastics in Agriculture
Hershey Lodge & Convention Center, Hershey, Pa.
814-238-7045.
September 26-27
Florida Agricultural Conference and Trade Show (FACTS)
Lakeland, FL.
Contact 850-995-1368 or 407-678-5337.
|
|
Gene McAvoy
Vegetable Extension Agent II Hendry County Extension Office PO Box 68 LaBelle, Florida, 33975 863-674-4092 |
The first 25% reduction in supplies in 1999 was less noticeable to growers as manufacturers were able to re-formulate the fumigant they supplied from the 98/2 standard that growers had traditionally used to a 67/33 ratio which hide most of the impact felt by growers in terms of product availability.
There is some legislation pending to attempt to level the playing field by allowing US growers to work under the same proposed phaseout as our competitors in developing nations. Perhaps, some of our more fore- sighted legislators will pass this bill and ease the pressure on US farmers.
Personally, I would not advise betting my continued operation on the passage of this legislation.
The advisory committee of the SW Florida Vegetable
Research Investment Fund has chosen to focus on this critical area of research.
Despite a lot of progress and attention to the problem, there are still
a lot of unanswered questions out there.
To date more than 30 growers and vegetable industry
supporters have contributed over $31,000 into the fund to support research
that will benefit our industry. What are you waiting for?
While methyl bromide and the cancellation or restriction of certain pesticide labels continues under FQPA, a new concern is looming for growers is SW Florida! SFWMD has announced new water quality regulations with respect to phosphorus that will affect growers in the C-139 basin of eastern Hendry County.
There is every indication that this development will not stop here and will extend to other drainage basins and possible encompass nitrogen as well as phosphorus in some areas. It appears that the future will bring greater attention and increased regulation of water quality leaving agricultural lands which will impact all aspects of agriculture in SW Florida.
As we have seen many times before the scientific basis for some of these actions is lacking or questionable at best.
What can you do - educate yourself and your legislators - get involved!
|
A Success Story in Progress |
 |
Tomato management in Florida has grown quite sophisticated over the years. Management practices include: introducing broadspectrum soil fumigants and herbicides into polyethylene mulched beds, precisely metering the application of fertilizer, lime and water, performing systematic biweekly scouting for pests, and judicious use of pesticides based on action thresholds.
These and other practices are part of a growing strategy known as Integrated Pest Management (IPM). Florida is a leader in fresh market tomato production because of a pro-active approach to Integrated Pest Management.
Why Protect Tomatoes With IPM?
· Tomatoes are the No. 1 vegetable crop in Florida. In 1996-97:
* 37,300 acres were planted;
* 1.4 billion pounds produced
(36,700 pounds per acre; and
* Tomatoes earned $462.5 million
in on-farm revenues, or 28.9 percent of the value of all Florida vegetables.
· Florida produces only fresh-market tomato
varieties that must be blemish-free to maintain their market value.
· Florida produces 40 percent of the fresh-market
tomatoes in the United States.
· Production costs are high - $11,600
per acre or $.33 per pound in 1997-98.
· Currently, chemical inputs are high,
with fertilizer, fumigants and pesticides accounting for 15 percent of
total production costs.
· Twenty-seven arthropods, 29 diseases
and 10 to 15 weeds are pests of tomatoes in Florida.
Principal Tomato Pests
Arthropods
The goal of IPM is to insure production of abundant, high-quality food using environmentally and economically sound methods. To achieve this goal, IPM emphasizes minimizing crop loss from pests by using any and all means at the grower's disposal. Growers can use resistant and tolerant varieties, and efficient cultural and management practices. They can monitor crops regularly to determine if and when control measures are needed. And they can apply biological control wherever possible.
Tomato growers began to adopt IPM in 1976-77, following a severe outbreak of leafminers that caused significant economic loss. This outbreak, which required as many as 34 insecticide sprays in a single 90-day season, was attributed to a build-up of pesticide resistance in the leafminers and pesticide-induced mortality in the leafminer parasites -a phenomenon common to crops receiving high chemical inputs. The outbreak served as a wake-up call to set in motion pilot IPM programs in Dade County, Florida.
IPM Benefits Tomatoes, and Florida, in Many Ways
 |
 |
 |
Growers and the general public have reaped the rewards thanks to IPM. Here's a look at some results of nearly 25 years of tomato IPM in Florida:
· Yields have risen dramatically from 29,000
to 36,700 pounds per acre in only 8 years (1988-89 to 1996-97).
· Fifty percent of growers routinely scout
for pests.
· Growers using IPM report 82 percent
reduction in overall pesticide use.
· Insecticide use has been significantly
reduced from an average of 8.9 pounds per acre in 1994-95, to 3.5 pounds
per acre in 1996-97.
· A shift toward using reduced-risk pesticides
is evident throughout Florida.
· New scouting companies with highly trained
personnel have developed.
· Scouting actions have detected outbreaks
of new and unusual diseases, enabling early intervention.
Why We Need Research
From the start, Florida IPM programs for tomatoes have been interdisciplinary, with components of horticulture, entomology, plant pathology and nematology. University of Florida scientists have made key contributions to the development and implementation of tomato IPM. For example, University of Florida researchers have:
· developed sampling methodologies for
scouting of all tomato pests in Florida;
· developed action thresholds for tomato
pests in Florida;
· provided data on pesticides that conserve
natural enemies;
· provided data on timing of pesticide
application to conserve natural enemies;
· developed monitoring and mating disruption
for tomato pinworm;
· studied effects of reflective mulches
on pest presence/dynamics, including virus transmission; and
· developed several disease-resistant
tomato varieties.
Future Challenges
Pest management in tomatoes is a constantly moving target. Although significant advances have been made in tomato IPM, new pests and other challenges continually need to be dealt with. For example:
· The removal of methyl bromide (MBr) as
a soil fumigant by 2005 is projected to reduce Florida tomato production
40 to 69 percent. To date, no single MBr alternative controls as
many pest problems as MBr fumigation.
· Potential introduction of new, invasive
pest species.
· Increased concern for natural resource
issues related to water availability, water quality and land use.
· Consequences of the Food Quality Protection
Act: Pesticides that are key to tomato management may be eliminated.
· Development of resistance to some of
the new reduced-risk pesticides; in many cases only one active compound
exists.
University of Florida Pest Alert
http://extlab7.entnem.ufl.edu/PestAlert/tomato2.htm
|
|
 |
First, a little background for those who may be confused by some of the jargon. When the EPA establishes the amount of pesticide that can legally remain on food (pesticide tolerance), the EPA must add together the risks of all pesticides (cumulative risk) that are poisonous in the same way (common mechanism of toxicity). The EPA also speaks of aggregate risks, but EPA aggregation refers to adding together all non-occupational exposure to a pesticide.
Organophosphate insecticides are the first group in the FQPA queue. In simple terms, these pesticides are characterized by phosphorous in a double bond with oxygen or sulfur (if you had not slept through chemistry, you could write this stuff). Additionally, all OP insecticides kill insects in the same way. They interfere with a key nerve enzyme acetyl-cholinesterase. Unfortunately, humans and other animals also use acetyl-cholinesterase. Fortunately, a 120-pound person weighs more than 25,000 times as much as an insect. Organophosphates are very common in both household and commercial products; common OP insecticides include malathion, chlorpyrifos (Lorsban/Dursban), diazinon, and acephate (Orthene).
Until now, the EPA has been estimating risks for individual organophosphates. The risk assessment of individual OP insecticides has resulted in some dramatic regulatory activity including removal of the #1 peach insecticide in the Southeast (methyl parathion) and elimination of all homeowner products containing chlorpyrifos.
The determination of cumulative risks is big,
big, big for anyone with interest in pesticides (pro or con). The
implementation of this policy will determine the fate of the organophosphate
pesticides, but it will also set precedent for how other groups of pesticides
(e.g., carbamates and B2 carcinogens) are evaluated. Take the time
to read the draft guidance document and offer comments. If you do
not understand the policy, let EPA know. The Agency is resolved to
make FQPA implementation a
‘transparent’ process.
No one wants to place human health or the environment at risk, but pesticides also offer tremendous benefits if used appropriately.
The Georgia Pest Management Newsletter
July 2000
|
|
 |
(Nature, via Kansas Pesticide Newsletter,
6-16-00)
The Georgia Pest Management Newsletter
July 2000
|
|
 |
(Pesticide & Tox. Chem. News,
6-15-00)
The Georgia Pest Management Newsletter
July 2000
| Transplant Age In Vegetables |  |
When transplants are thought to be too old, concerns
are raised about their subsequent growth and yield potential. Vavrina
reviewed the majority of research available on
transplant age and when the results of the research are distilled down
to the ideal transplant age for setting a specific crop, the recommendations
generally agree with those found in "Knott's Handbook for Vegetable Growers"
(see below).
Tomatoes:
Vavrina and Orzolek (1993) concluded that transplant age had little bearing on tomato production. Other key points by researchers include:
1. Young transplants (3-4 weeks) old reduce production
costs but may be harder to pull from containers without injury.
2. Older transplants (7-9 weeks) tend to produce
early yields.
3. Guidelines of 4-7 weeks for tomatoes are appropriate.
If the grower must replant, the use of older plants should not reduce yield,
fruit size or earliness.
Peppers:
Nicklow in a NY study found that pepper transplants without flower buds or with unopened flower buds produced more large fruit (early and total) than transplants with open blooms or small fruit. Weston in KY, used containerized transplants of 4, 6, 7, and 9 weeks. She found 70% more early U.S. Fancy and No. 1 fruit with 9 week old transplants. Total Fancy, No. 1 and overall yield was not affected by transplant age. Three of the studies reported in the article indicate that pepper transplants of 8 to 11 weeks may have a yield advantage for early size and number of fruit.
Cucurbits (Watermelon, Squash, muskmelon):
Research implies that transplant age does not adversely influence yield in cucurbits. Commercially, 3 to 4 week old transplants are used for general cucurbit production. Some of the findings reported that cucurbits can be held beyond this time frame without fear of yield loss. However, practical experience shows that large transplants are difficult to handle and they may require large amounts of water to become established.
Broccoli:
Research is not conclusive but older seems to be better.
Cabbage:
Transplant age did not influence cabbage early or total yield.
Cauliflower:
Research results are conflicting, more work is needed.
Lettuce:
Boa (1979) found a minor effect of transplant age on butterhead lettuce, finding older transplants tended to produce lighter heads.
In General:
New information suggests that the transplant age window for certain crops might be wider than previously thought. Older transplants generally result in earlier yields while younger transplants will produce comparable yields but take longer to do so. Modern cultivars and improved production technology enable growers to produce high yields despite transplant age.
Bottom Line:
Vavrina suggests, that if vegetable growers must reset plants after a freeze, flood, etc., they should not fear the older plants usually found at the transplant production facility.
(Lorenz and Maynard, 1988)
By C. S. Vavrina. 1998
HortTech 8(4).
|
GOLF TOURNAMENT |
 |
Breakfast, course refreshments, and lunch will be provided. Following the 7:30 a.m. continental breakfast, the Tournament will begin at 8:30 a.m. sharp. Lunch and awarding prizes takes place immediately following the tournament. If you desire a particular 4-some, please notify FFVA no later than September 8. Any questions related to the tournament can be addressed by calling (407) 894-1351.
|
Generally Acceptable |
 |
Chemically Speaking
July 2000
|
|
 |
Farmworker advocacy groups, growers and state agencies were among the stakeholders who attended the two-day event.
Small working group meetings resulted in the identification of many specific concerns. These included:
TRAINING
(Pesticide and Toxic Chemical News, Vol. 26, No. 33)
|
Special Review Status Report |
 |
The goal of this process is to reduce the risks posed by a pesticide to an acceptable level while taking into consideration the benefits provided from the use of the pesticide. More than 100 pesticides have been examined in the Special Review process. This report provides brief summaries of those reviews and the risk concerns that prompted them and cites EPA decision documents that provide more detailed discussion. The report is available on the Office of Pesticide Programs' internet web site Printed copies of the document will be available from EPA's National Service Center for Environmental Publications, telephone 1-800- 490-9198 (request publication number EPA 738-R-00-001).
(EPA Pesticide Program Update 04/17/00)
Chemically Speaking
July 2000
|
|
 |
FQPA SPOTLIGHT
June 30, 2000
Volume 4, Issue 21
|
|
 |
Novartis has added the control of whiteflies,
aphids and thrips on ornamentals to their AVID®
(abamectin) label.
(Agrichemical News, June 15, 2000)
As a result of the IR-4 Project, EPA established
residue tolerances on squash and cucumbers for DANITOL® (fenpropathrin)
-
(Agrichemical News, June 15, 2000)
|
|
 |
FARMERS, you can help, and WE CAN HELP YOU.
We are interested ONLY in produce that you cannot sell. We will provide groups of volunteers to come and glean your unmarketable produce and transport it to agencies that help ease the problem of hunger. These volunteers sign waivers to relieve issues of liability and are accompanied by a trained Field Supervisor.
PLEASE call us soon to help the hungry people of Florida or for more information. Thank you.
Ame See, Program Coordinator 1-800-806-0756.
|
|
 |
The first is a reminder that inspectors with the Bureau are now in strict compliance mode, issuing fines for violations of the Standard.
Secondly, expect the EPA to continue to make the regulation more strict -especially regarding pregnant women and children. Dubberly also noted that companies have been cited for not training mechanics as handlers. Mechanics may be exposed to chemicals while repairing equipment, and are therefore required by the Standard to be trained as handlers.
Finally, emember that new workers must be trained within the first five days of employment, and all other employees should receive training every three years.
Glades Manpower Development Newsletter
June 2000
|
|
 |
The following characteristics should be considered in selection of tomato varieties for use in Florida.
Yield -The variety selected should have the potential to produce crops at least equivalent to varieties already grown. The average yield in Florida is currently about 1400 25-pound cartons per acre. The potential yield of varieties in use should be much higher than average.
Disease Resistance -Varieties selected for use in Florida must have resistance to Fusarium wilt, race 1 and race 2; Verticillium wilt (race 1); gray leaf spot; and some tolerance to bacterial soft rot. Available resistance to other diseases such as Fusarium wilt, race 3 may be important in certain situations
Horticultural Quality -Plant habit, stem type and fruit size, shape, color, smoothness and resistance to defects should all be considered in variety selection.
Adaptability -Successful tomato varieties must perform well under the range of environmental conditions usually encountered in the district or on the individual farm.
Market Acceptability -The tomato produced must have characteristics acceptable to the packer, shipper, wholesaler, retailer and consumer. Included among these qualities are pack out, fruit shape, ripening ability, firmness, and flavor.
Current Variety Situation
Many tomato varieties are grown commercially in Florida, but only a few represent most of the acreage.
‘Florida 47' was grown on about 36% of the acreage in Florida in the 1999-2000 season -a notable increase from the approximately 23% of the acreage the previous season. ‘Florida 47' was grown on about 47% of the acreage in southwest Florida and 32% of the east coast acreage.
‘Sanibel’ had about 14% of the state's acreage. It was the predominant variety in Miami-Dade County with almost 60% of the acreage.
All BHN varieties are lumped together and comprise about 13% of the state's acreage, mostly in southwest Florida and north Florida.
‘Solar Set’ acreage increased to over 12% of the state total mostly in west-central Florida.
‘Florida 91' acreage increased to about 7% from a fraction the previous year. The Palmetto-Ruskin area was the principal production site.
Other varieties with some acreage in the 1999-2000 season were the long-time popular ‘Agriset 761' (5%), ‘Solimar’ (5%), and ‘Sun Chaser’ (2%). Many other varieties and advanced experimental hybrids were grown on less than I % of the state's acreage.
Tomato Variety Trial Results
Summary results listing the five highest yielding and the five largest fruited varieties from trials conducted at the University of Florida's Gulf Coast Research and Education Center, Bradenton; Indian River Research and Education Center, Fort Pierce and North Florida Research and Education Center, Quincy for the Spring 1999 season are shown in Table 1.
High total yields and large fruit were produced
by ‘BHN 399' at Bradenton, ‘Agriset 761', ‘Solimar’ and ‘Floralina’ at
Fort Pierce, and ‘Florida 7851' at Quincy. ‘Florida 7815' produced
high yields at two of the three locations. ‘Sanibel’ produced large
fruit at
all three locations and ‘Solimar’ at two locations.
Not all entries were grown at each location.
Tomato Varieties for Commercial Production
The varieties listed have performed well in University of Florida trials conducted in various locations.
Large Fruited Varieties
Agriset 761. Midseason, determinate, jointed hybrid. Fruit are deep globe and green shouldered. Resistant: Verticillium wilt (race 1), Fusarium wilt (race I and 2), Alternaria stem canker, gray leaf spot. (Agrisales).
BHN-444. Early-midseason maturity. Fruit are globe shape but tend to be slightly elongate, and green shouldered. Not for fall planting. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1. and 2), and Tomato Spotted Wilt Virus. For Trial. (BHN).
Florida 47. A late midseason, determinate, jointed hybrid. Uniform green, globe-shaped fruit. Resistant: Fusarium wilt (race I and 2), Verticillium wilt (race 1), Alternaria stem canker, and gray leaf spot. (Asgrow).
Floralina. A midseason, determinate, jointed hybrid. Uniform, green shoulder, flattened globe shaped fruit. Recommended for production on land infested with Fusarium wilt, Race 3. Resistant: Fusarium wilt (race l, 2, and 3), Verticillium wilt (race 1), gray leaf spot. (Petoseed).
HA 3057. Early-midseason maturity. Uniform green shoulder, flattened globe-shaped fruit. Heat tolerant. Resisant: Fusarium wilt (race 2), Verticillium wilt (race 1.), TMV, and TYLCV. For Trial. (Hazera).
Solar Set. An early, green shouldered, jointed hybrid. Determinate. Fruit set under high temperatures (920F day/720 night) is superior to most other commercial varieties. Resistant: Fusarium wilt (race I and 2), Verticillium wilt (race 1), Alternaria stem canker, and gray leaf spot. (Asgrow).
Sanibel. A late midseason, jointless, determinate hybrid. Deep oblate shape fruit with a green shoulder. Tolerant/resistant: Verticillium wilt (race l.), Fusarium wilt (race 1. and 2), Alternaria stem canker, root knot nematode, and gray leaf spot. (Petoseed).
Solimar. A midseason hybrid producing globe-shaped, green shouldered fruit. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1 and 2), Alternaria stem canker, gray leaf spot. (Asgrow).
Sunbeam. Early midseason, deep-globe shaped uniform green fruit are produced on determinate vines. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1 and race 2), gray leaf spot, Alternaria. stem canker. (Asgrow).
Plum Type Varieties
Marina. Medium to large vined determinate hybrid. Rectangular, blocky, fruit may be harvested mature green or red. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1 and 2), Alternaria stem canker, nematodes, gray leaf spot, and bacterial speck. (Sakata).
Plum Dandy. Medium to large determinate plants. Rectangular, blocky, defect free fruit for fresh market production. When grown in hot, wet conditions, it does not set fruit well and is susceptible to bacterial spot. For winter and spring production in Florida. Resistant: Verticillium wilt, Fusarium wilt (race 1), early blight, and rain checking. (Harris Moran).
Spectrum 882. Blocky, uniform-green shoulder fruit are produced on medium-large determinate plants. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1 and 2), root-knot nematode, bacterial speck (race 0), Alternaria stem canker, and gray leaf spot. (Petoseed).
Supra. Determinate hybrid rectangular, blocky, shaped fruit with uniform green shoulder. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1 and 2), nematodes, and bacterial speck. (Novartis).
Veronica. Tall determinate hybrid. Smooth plum type fruit are uniform ripening. Good performance in all production seasons. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1 and 2), Alternaria stem canker, nematodes, gray leaf spot, and bacterial speck. (Sakata).
Cherry Type Varieties
Mountain Belle. Vigorous, determinate type plants. Fruit are round to slightly ovate with uniform green shoulders borne on jointless pedicels. Resistant: Fusarium wilt (race 1), Verticillium wilt (race 1). For Trial. (Novartis).
Cherry Grande. Large, globe shaped, cherry-type fruit are produced on medium-size determinate plants. Resistant: Verticillium wilt (race 1), Fusarium wilt (race 1), Alternaria stem blight, and gray leaf spot. (Petoseed).
Reference:
Maynard, D. N. (ed.). 2000. Vegetable variety trial results in Florida for 1999. Fla. Agr. Expt. Sta. Circ.S-396.
Tomato variety evaluations were conducted in 1999 by the following University of Florida faculty:
D. N. Maynard -Gulf Coast Research & Education
Center -Bradenton
S. M. Olson -North Florida Research & Education
Center -Quincy
J. W. Scott -Gulf Coast Research & Education
Center -Bradenton
P. J. Stoffella -Indian River Research &
Education Center -Fort Pierce
(Maynard and Olson, Vegetarian 00-07)
Vegetarian Newsletter
July 2000
Agrisales: Agriset 761, ASX 202, ASX 9110.
Asgrow: Florida 47, Sunbeam, Sunpak, Solimar.
BHN: BHN 248, BHN 399, BHN 444.
North Carolina State University: NC 96365.
Novartis: RFT 6131B.
Petoseed: Floralina, Sanibel, PS 647095, PS 69696.
University of Florida: Florida 7815, Florida
7851, Florida 7862.
Summary results listing the five highest yielding and five largest fruited entries from trials at the University of Florida's Gulf Coast Research and Education Center, Bradenton; the Indian River Research and Education Center, Ft. Pierce; and the North Florida Research and Education Center, Quincy for the fall 1999 season are shown in Table 2.
High total yields and large fruit size were produced by ‘Florida 7816' at Bradenton; ‘Equinox’, ‘Florida 7816', and ‘Florida 7921' at Fort Pierce; and ‘BHN 120A’ and PX 647095 at Quincy. ‘Florida 7885' and ‘Florida 7921' produced high yields at all three locations. ‘Florida 7816' produced large fruit at all locations. Again, not all entries were included at all locations.
Overall, results of these trials indicate that no single variety dominates the industry as during the periods when ‘Sunny’ and ‘Agriset 761' were preeminent. Furthermore, varieties appear to be more location and seasonal specific than in the past.
Agrisales: Agriset 761, Equinox.
Asgrow: Florida 47, Florida 91, Solar Set, Sunbeam.
BHN: BHN 120A, BHN 190, BHN 273.
Hazera: HA 3017B.
Petoseed: Captiva, PX 647095
University of Florida: Florida 7816, Florida
7885, Florida 7921.
 |
 |
 |
|
|
 |
Under the summer heat transplanted pepper plants can develop, often with in hours of transplanting, a condition known by such names as “heat stress,” “Plastic damage,” “heat girdling” or “stem scalding.”
Many assume this phenomenon is caused by the “flap” made by stretching the plastic mulch during the mechanical hole punching operation and hence the term “plastic damage.” However, the phenomenon occurs quite nicely even in the absence of a plastic “flap.”
What then is causing this heat girdling?
A study designed to look at transplant plug moisture levels in the field
proved fruitless as heat girdling occurred in all treatments regardless
of plug moisture levels. However, we realized that efforts to establish
the treatments had taken so long everything was
transplanted between 11 a.m. and noon.
Plants set during the peak sun hours basically bypassed the adjustment phase just trying to cool themselves (i.e., transpiration) and when the transplant plug ran out of water heat girdling occurred! Other factors must certainly be at play (air and soil temperatures, stem pressure potentials, drying winds, etc.) but time of day definitely makes a difference. Your production schedule may not allow you to discontinue planting from 11 a.m. to noon for example, but if you do, we believe your need for resets will be reduced.
Weather plays a dominant roll as well. Our efforts to establish how soon water should be applied following field setting were foiled because we set out our trial on a day when the solar insolation was only half that of the day we established the time of planting trial (though it seemed very hot and bright to us!).
We were able to determine however, that using the water wagon sooner rather than later was much better and that bed wetness also affected heat girdling (more scalding on the road bed than on the ditch bed).
These studies will be repeated this month so, we will keep you posted. But, the next time you are planting pepper in the summer you should take a cue from the old saying “only mad dogs and Englishmen go out in the noon day sun.” Perhaps there's a lesson here for the pepper grower as well!
C.S. Vavrina, Ph.D
Associate Professor, Vegetable Production
University of Florida Southwest Florida Research
and Education Center
Immokalee, Fla., 941-658-3400.
|
|
 |
Weather conditions can raise havoc with spray timing intervals. When given the choice between spraying less material more often vs. more material less often, it is almost always preferential to spray less material on a more frequent basis. (Foliage missed by the first spray application will almost certainly be contacted by the second spray application.)
|
|
 |
Microbial insecticides are comprised of microscopic living organisms (viruses, bacteria, fungi, protozoa, or nematodes) or the toxins produced by these organisms. They are formulated to be applied as conventional insecticidal sprays, dusts, or granules.
Advantages of Microbial Insecticides
Individual products differ in important ways, but the following list of beneficial characteristics applies to microbial insecticides in general.
The organisms used in microbial insecticides are essentially nontoxic and nonpathogenic to wildlife, humans, and other organisms not closely related to the target pest. The safety offered by microbial insecticides is their greatest strength.
The toxic action of microbial insecticides is often specific to a single group or species of insects, and this specificity means that most microbial insecticides do not directly affect beneficial insects (including predators or parasites of pests) in treated areas.
If necessary, most microbial insecticides can be used in conjunction with synthetic chemical insecticides because in most cases the microbial product is not deactivated or damaged by residues of conventional insecticides. (Follow label directions concerning any limitations.)
Because their residues present no hazards to humans or other animals, microbial insecticides can be applied even when a crop is almost ready for harvest.
In some cases, the pathogenic microorganisms can become established in a pest population or its habitat and provide control during subsequent pest generations or seasons.
Disadvantages of Microbial Insecticides
The limitations or disadvantages listed do not prevent the successful use of microbial insecticides. Understanding how these limitations affect specific microorganisms will help users to choose effective products and take necessary steps to achieve successful results.
Because a single microbial insecticide is toxic to only a specific species or group of insects, each application may control only a portion of the pests present in a field, garden, or lawn. If other types of pests are present in the treated area, they will survive and may continue to cause damage. Conventional insecticides are subject to similar limitations because they too are not equally effective against all pests.Nonetheless, the negative aspect of selectivity is often more noticeable for microbials.
Heat, desiccation (drying out), or exposure to ultraviolet radiation reduces the effectiveness of several types of microbial insecticides. Consequently, proper timing and application procedures are especially important for some products.
Special formulation and storage procedures are necessary for some microbial pesticides. Although these procedures may complicate the production and distribution of certain products, storage requirements do not seriously limit the handling of microbial insecticides that are widely available. (Store all pesticides, including microbial insecticides, according to label directions.)
Because several microbial insecticides are pest-specific, the potential market for these products may be limited. Their development, registration, and production costs cannot be spread over a wide range of pest control sales. Consequently, some products are not widely available or are relatively expensive (several insect viruses, for example).
R. Weinzierl, T. Henn and P. G. Koehler
UF/IFAS
|
|
 |
 |
 |
Teaching:
Author unknown, (or was it the
Tenure and Promotion Committee?)
|
about Government and Bureaucracy: |
 |
Pythagorean theorem:....................24 words
Lord’s Prayer:...............................66
words
Archimedes’ Principle:...................67 words
10 Commandments:.......................179 words
Gettysburg address:.......................286
words
Declaration of Independence:.........1,300 words
US Government regulations on the sale of cabbage:.........................26,911
words !
