Institute of Food and Agricultural Sciences
Southwest Florida Vegetable Newsletter
May - June 2002
May 14, 2002
Spring Vegetable Field Day -10 AM -Noon
Southwest Florida Research and Education Center
Call Sheila at 863-674-4092 to RSVP.
July 10-12, 2002
70th Annual Florida Fertilizer & Agrichemcial Association
Palm Beach, Florida
Contact FFAA for more information at 863-294-8626 or www.ffaa.org.
July 14 - 16, 2002
GAPS - Good Agricultura Practices Workshop
Department of Food and Human Nutrition
University of Florida
Contact Joyce Taylor at 352-392-1991 ext 207 to register.
July 16, 2002
Farming in the new Millenium - Risk Management Seminar
Florida Farm Bureau
For more information go to http://FloridaFarmBureau.org/risk
August 5, 2002
General Standards/ Core Test Review - 8:00 am to 10:00 am.
Ornamental & Turf Test Review - 1:00 pm to 3:00 pm
West Palm Beach, Florida.
For more information call 561-233-1700
August 14, 2002
Pesticide Testing in any category - 8 am to 4 pm.
Palm Beach County Extension Office
Belle Glade, Florida
For more information call 561-996-1655.
September 4-6, 2002
The 26th Annual Joint Tomato Committee and
Florida Tomato Committee Meeting
Ritz Carlton Hotel
Contact Phyllis Gilreath at 941-722-4524
December 8-12, 2002
Naples Beach and Golf Club
Contact Don Maynard at 941-751-7636 ext 239 or email@example.com
Vegetable Extension Agent II
Hendry County Extension Office
PO Box 68
LaBelle, Florida, 33975
If this is representative of the magnitude of yield reduction that the average grower can expect from the various methyl bromide alternatives this is truly alarming. It should be alarming to growers as it is hard to see how Florida vegetable producers can remain competitive in the global market place with this magnitude of an environmentally mandated handicap.
While it may not be yet — this level of yield reduction should be equally alarming to the public and the environmental community as well. To the American public who enjoy the most abundant and affordable food supply on the planet, this would signal higher prices and possibly an end to the agricultural bounty that has been enjoyed and taken for granted for the last 50 years.
It should also be alarming to the environmental community and proponents of sustainable agriculture world-wide for several reasons. High yield agriculture based on research and technology in the area of biology, ecology, chemistry, and genetics has improved the human condition for peoples worldwide.
As the worlds population continues to grow -some estimates indicate a doubling in the next 50 years—the greatest menace to the earth’s environment and bio-diversity of natural systems is habitat loss through the conversion of natural ecosystems to agriculture.
In addition to bounty enjoyed here at home, high yield agriculture has helped better the lives of literally billions of people around the globe leading to a higher standard of living and a basis for global stability.
If we chose to adopt reduced yields in a false bid to achieve agricultural sustainability, the impacts on the worlds ecological systems could be catastrophic. Maintaining food supplies at current levels (where 1 in 5 of earths citizens are on the verge of starvation) would mean that we would have to increase the amount of land under the plow from the current 6 million square miles to as much as 25 to 30 million square miles over the next quarter century. This would entail plowing down the diverse ecosystems of entire continents to avoid the use of modern farm inputs.
Clearly the best hope for humankind and the preservation of our planets rich ecological diversity is to embrace agricultural technology and continue to support research aimed at producing more food on less land through the use of modern technology.
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Specialty crop growers have access to programs in ways never seen before. For example, in the next six years $1.2 billion will be purchased through USDA’s commodity purchases.
“The Farm Bill agreement embodies most of the goals, principles, and policy recommendations we presented to Congress and the Administration last year,” said Robert Guenther, United Fresh Fruit and Vegetable Association’s (United) vice president of government and public affairs. “The Farm Bill also establishes a foundation for the produce industry to develop federal policy in the future that will help the industry increase produce consumption, drive market access, and develop the tools necessary for a profitable and successful produce industry.”
Eighteen months ago the produce industry started
working to ensure that the priorities of the produce industry were included
in this Farm Bill debate, according to Guenther. The industry unified
to develop a plan for federal farm policy with fruit and vegetable priorities
an integral part of American agriculture.
The Farm Bill, titled “The Farm Security and Rural Investment Act of 2002” will dictate federal agriculture policy over the next six years. These provisions address key priority areas important to the produce industry:
International market access
The new technical Assistance for Specialty crops Fund will provide USDA’s Foreign Agricultural Service (FAS) funding ($2 million per year) to address non-tariff trade barriers for specialty crops in an effort to increase market access.
Market Access Program (MAP) funding includes a
10-year increase of $650 million over the current $90 million baseline.
The MAP program will be ramped up to $200 million by 2006. MAP has
been an important trade tool for the produce industry where some 30% of
the funding is utilized by fruit and vegetable industry members to gain
access to international markets.
Food aid report
A report will look at the need to improve infrastructure to allow for more perishable commodities such as fruits and vegetables in federal food aid programs.
Increase produce consumption
Commodity purchases - Includes funding under Section 32, which will require the secretary to purchase at least $200 million in fruits and vegetables and other specialty food crops. For the first time during a Farm Bill policy deliberation, Congress has directed the USDA to ensure that at least $200 million is used for the purchase of fruits and vegetables for federal feeding programs such as the School Lunch Program. In the next six years the federal government will purchase $1.2 billion in fruits and vegetables. More importantly, Congress has indicated they expect USDA to utilize this funding above and beyond current purchasing practices.
DOD Fresh program - As part of the additional purchases under Section 32, $50 million per year shall be used for additional funding under this program. The USDA currently provides $25 million each year for the purchase of fresh fruits and vegetables for the schools, pursuant to existing authority under the School Lunch Act. Through a 1995 memorandum of agreement between the Agricultural Marketing Service, the Food & Consumer Service, and the Defense Personnel Support Center, the Department of Defense serves as the servicing agency for the procurement of these fresh fruits and vegetables through the DOD Fresh program.
Fruit and Vegetable Domestic Promotion Program
- A new $10 million per year cost-share pilot program will carry out
demonstration projects to increase fruit and vegetable consumption and
convey a health promotion message.
Water Conservation Program - This program, funded at $60 million per year, will provide cost-share incentives and assistance for efforts to conserve ground and surface water.
EQUIP - This widely popular program with fruit and vegetable growers has been increased four-fold to achieve $1.3 billion in annual funding levels. Congress has included language highlighting priority practices for produce growers, which include IPM practices, invasive species and preservation of endangered habitat. Report language was also included that emphasizes the conference committee members’ expectations that adequate resources are made available for specialty crop conservation needs.
Free Fresh fruits & Vegetables in Schools - This pilot program will allow school children to have access to free fresh fruits and vegetables throughout the school day.
Fruit and Vegetable Food Stamp Project - Pilot projects will be developed to increase access and outreach for Food Stamp recipients. The Secretary of Agriculture can make grants to state agencies and other entities to help develop these pilot projects. One program encourages consumption of fruits and vegetables by developing a cost-effective system for providing discounts for purchases of fruits and vegetables made through use of the electronic benefit transfer cards.
Planting Flexibility - Maintains current planting restrictions on program crop commodities.
Country-of-origin labeling - Beginning Sept. 30, 2004, fruit and vegetables will be required to have country-of-origin labeling. For the next two years, labeling will be voluntary.
Methyl Bromide - State, local, and tribal governments will be allowed to petition USDA for use of Methyl Bromide for the official control of pests, recognizing economic costs and availability of suitable alternatives. The agreement also provides that these governments may petition USDA for the use of transitional products. If transition products are not feasible, than USDA must issue a report. Regulatory reviews must occur within 180 days.
Mechanical harvesting - The bill authorizes research and Extension grants for improved harvesting productivity of fruits nd vegetables including research on mechanical harvesting and development of abscission chemicals.
“Through the work of United members, the allied Association Council and most importantly the Farm Bill Working Group, we were able to develop and advocate a set consensus-driven policy proposals which were presented to Congress,” said Guenther. United applauded Congress and members who led the fight to develop the most progressive and positive agriculture policy initiatives developed through a Farm Bill process. The bill addresses the unique needs of fruit and vegetable producers in the United States, said Guenther.
The Vegetable Growers News
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“Many of the provisions are milestones for the industry. Finally, we will begin to get data on the organic industry that’s been lacking as well as more research to help advance farmers’ use and understanding of effective organic practices,” said Katherine DiMatteo, OTA’s executive director. “The Farm Bill’s provisions will give farmers the tools they need to transition to organic agriculture and the knowledge they need to become viable, organic businesses.”
Provisions for organic agriculture throughout the 2002 Farm Bill include:
Organic agriculture, which still represents a small portion of U.S. agriculture, is growing at a fast rate. The U.S. market for organic food and beverage products has experienced 20-24% growth each year for more than the past decade, and is expected to continue to grow, particularly with full implementation of national organic standards in October.
The Vegetable Growers News
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This official recognition means that plant-based agricultural products from the United States operations certified as meeting U.S. organic standards may be labeled or represented in Japan as organic, according to USDA. The recognition agreement does stipulate, however, that alkili-extracted humic acid, lignin sulfonate and potassium bicarbonate, may not be used in raw or processed organic food exported to Japan. These substances are allowed under the U.S. organic standards.
The recognition agreement replaces and expands upon a temporary agreement that allows U.S. plant-based organic food ingredients to be exported to Japan and sold as organic. The temporary agreement expired on March 31.
This announcement will allow U.S. producers to make inroads into Japan’s approximately $1 billion-a-year organic food market. USDA’s national organic standards will be fully implemented by Oct. 21, and all producers, handlers and processors of organic agricultural products, both foreign and domestic, must meet these standards in order to label their products organic.
The Vegetable Gower’s News
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The Georgia Pest Management Newsletter
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The decision by Mexico’s largest group of tomato growers to withdraw from the agreement -- which sets a price floor on wholesale tomatoes -- will trigger a new probe by the U.S. Commerce Department into whether Mexican tomato producers sell their produce below cost in the United States, a practice known as “dumping.”
If Commerce finds no evidence of dumping, Florida growers could face a flood of low-cost tomatoes this winter, a reprise of the situation in the early 1990s. If there is evidence of selling below cost, Florida growers will compete with Mexican producers who have to pay import duties.
The Confederation of the Agricultural Associations of Sinaloa sent a letter to the Commerce Department last Thursday, informing them of the decision to withdraw from the 1996 agreement suspending the anti-dumping investigation into fresh tomatoes from Mexico.
Already, Florida growers have signaled they are ready for new hostilities. Their own trade group, Florida Farm, plans to send a letter to members of the Florida congressional delegation and ask them to vote against giving the president enhanced trade negotiating powers, known as “fast track,” said Florida Farm trade advisor J. Luis Rodriguez.
The winter tomato conflict was one of the small, but hot button, issues that arose after the North American Free Trade Agreement was implemented in 1994.
Former President Bill Clinton had pledged to protect Florida growers in a letter, which clinched crucial Florida congressional votes to pass NAFTA. After a 40 percent devaluation of the Mexican peso starting in December 1994, Florida farmers charged they were being put out of business by cheap imports and filed an “anti dumping” complaint.
The preliminary Commerce investigation into whether tomatoes were being “dumped” concluded that a number of Mexican producers were selling below cost.
Commerce set an average duty of 17.5 percent, but at the last minute, the process was suspended when Mexican growers agreed to a price floor of about $5.65 for a 25-pound box.
Mario Robles, manager of the Committee to Investigate and Defend Vegetables in Sinaloa, said that the agreement had worked for the first two years, but that growers’ recent complaints of violations had fallen on deaf ears on both sides of the border. Baja California producers and U.S. producers sold their tomatoes at whatever price they could obtain.
“There was unfair competition between signers
of the agreement and nonsigners,” Robles said.
Paul DiMare, one of South Florida's biggest growers, agreed.
“They could not enforce it, to be honest, on both sides, on the Mexican side and on the American side,” DiMare said. He predicted that U.S. investigators, who look at the finances and production numbers at different Mexican producers, would find evidence that tomatoes were being sold too cheaply and place new duties on tomato imports.
But financial conditions have changed since the 1996 investigation. The cheap Mexican peso of 1996 has become expensive against the dollar, increasing domestic production costs.
Consumers have always been sidelined in this particular
trade war. No matter how low the price goes, to the point where producers
saved money by leaving unpicked tomatoes on the vine, supermarket prices
never dipped by the same amount.
The price agreement will end July 31 and Commerce should have the results of its probe by October.
June 5, 2002
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“The Farm Bill package contains important programs that will help our growers remain competitive,” said Mike Stuart, president of the Florida Fruit & Vegetable Association (FFVA). FFVA identified labeling requirements as one of the key successes in the bill.
For many growers, the Farm Bill provision mandating country-of-origin labeling of fresh fruits and vegetables is the most important, the association reported. Starting September 2004, the labeling law would require food retailers to ensure that fresh produce and other food products are labeled indicating their country-of-origin. Surveys show that consumers overwhelmingly support country-of-origin labeling, and that many consumers are unaware that imported produce is sold in their supermarkets.
The potato industry also supported the measure. When the final agreement on the 2002 Farm Bill included a country-of-origin labeling provision, National Potato Council (NPC) supported it, even though the issue has been a hotly contested aspect of the bill. The provision as approved will establish a program for labeling fruits and vegetables that will be voluntary for two years before becoming mandatory.
“We believe the country-of-origin provisions will provide valuable information for consumers to allow them to choose high quality U.S. potatoes,” said NPC President Todd Michael.
Since 1979, Florida has required country-off-origin labeling in the store for fresh produce. Florida's positive experience with the law helped generate support for the national labeling initiative. Recently, Washington state also passed their own country-of-origin labeling law, despite the discussion of a new law in the Farm Bill.
“Florida consumers have had origin information for years and have used it as a tool for choosing which foods to buy,” said Hugh English, FFVA chairman.
The new Farm Bill includes other important provisions for fruit and vegetable producers. The bill increases funding for the Market Access Program (MAP), from its current $90 million to $200 million in 2006. Increased MAP funding will help fruit and vegetable producers boost export market development campaigns.
The National Potato Council (NPC) supported the passage of the bill based on the inclusion of provisions that met the potato industry objectives for planting flexibility, international market access and increased potato utilization by feeding programs.
“The potato industry hard to support the industry the inclusion of programs and dollars that would improve the market opportunities for potatoes and potato products,” said Michael.
A primary goal of the NPC strategy included insuring that planting flexibility restrictions were not expanded beyond what was included in the 1996 Farm Bill. “The relationship between program and non-program crops is very delicate,” Michael points out, “and small changes in potato acres can have a dramatic impact on potato prices.”
A broad coalition worked for more than two years to raise awareness in Congress about the critical needs of specialty crop producers. Agriculture officials from several states, producers and more than 100 industry organizations contributed testimony and resources to seek common objectives for the new Farm Bill.
The Vegetable Growers News
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Here is the big question. After all the regulatory activity surrounding the organophosphates; after all of the millions of dollars; after removing critical insecticides from dozens of minor crops; have we really improved the safety of the American diet? Many people would say no. In my opinion, it would be impossible to empirically prove that the safety of the U.S. food supply has changed significantly. The following question and answer is directly from the EPA web page. The answer seems to dance around the big question that opened this paragraph.
How does this new assessment increase public health protection?
This assessment supports the high level of regulatory confidence in the safety of the food supply. By evaluating the potential for combined exposures to two or more organophosphate pesticides, the assessment moves beyond the already high level of protection of public health provided by the individual aggregate assessments. Looking at exposure over time helps take into account the potential effects of additional exposure before complete recovery from any given exposure. It also evaluates variation in exposure from drinking water and residential uses in different areas of the country. The assessment includes the FQPA safety factor for protecting sensitive populations, e.g., infants and children.
It is easy to get caught up in emotion and rhetoric that every risk to children should be eliminated regardless of the cost. If that assumption were really true, we should eliminate cars. Gasoline is toxic and carcinogenic; thousands of children are killed in car accidents; air pollution from cars is a known health hazard. Clearly, however, the advantages of cars outweigh these disadvantages. Pesticides are a big part of the success of the U.S. because so few people can produce food for everyone. Thus, everyone else is free to be doctors, engineers, scientists, businessmen, etc
The Georgia Pest Management Newsletter
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Ecolabeling faces two challenges. First, to ensure that an ecolabel identifies a product that is more environmentally friendly. Someone has to decide which products are more environmentally friendly, and beauty is often in the eye of the beholder. Suppose one crop is produced without pesticides, but the production causes greater erosion of soil. Many people might pick the product without pesticides, but EPA identifies erosion as the chief threat to surface water.
The second, perhaps bigger, challenge for ecolabeling is consumer education.
Consumers are bombarded with a tremendous amount of information about the value of particular products, and buyers are somewhat jaded by manufacturers’ claims. To be successful, ecolabeling would have to be clearly different from the other products and convince potential buyers that the ecolabeling claims are true.
Many people consider organic labeling a type of ecolabeling. Consumers were confused by the barrage of organic claims; there was no uniform definition for ‘organic,’ and unscrupulous companies were exploited the organic market to sell their ‘unorganic’ products.
If you are interested in the Conference on Ecolabels and the Greening of the Food Market, contact Willie Lockeretz, Friedman School of Nutrition Science and Policy, Tufts University, Medford, MA 02155 at 613-627-5264 or firstname.lastname@example.org. The conference was organized by the Friedman School of Nutrition Science and Policy, Tufts University. Companies and environmental groups that offer, use, or are considering ecolabels; inspection and certification bodies; academic and private research groups; trade and consumer-interest groups; and food labeling-related government agencies are invited to attend. Topics include current uses of ecolabels, their known effects on food marketing, and ecolabeling controversies. You can register at this web site http://nutrition.tufts.edu/conted/ecolabels for $125 U.S.
The Georgia Pest Management Newsletter
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The most important thing we can tell you is that methyl bromide has a lot of slop built into the system and the alternatives do not. Methyl bromide is fairly forgiving. You can apply it when it is a lot too wet or a bit too dry and you often will have good results. You can be slow covering it and you will still get some control, as long as your delay is within reason. All of the alternatives require much greater attention to details and application conditions. Apply Telone C-35 to soil which is too wet and you will have problems. Use an S-tine harrow or field cultivator to incorporate herbicide when the soil is wet or dry and your weed control will suffer. Pump Vapam through the drip tube for too short of a time and you will have weed control in a strip over the drip tube. Pump it with too much water and your middles will be clean and so will your sinuses. Even if you think your commodity will get a critical use exemption for continued use of methyl bromide, you can learn from what we are going to tell you. Earlier, we said that herbicide application is an art. An artist is who he or she is because he cares about his art and pays attention to the details, always trying to learn and improve. Someone who is really good on a tractor is an artist in his own way because he has worked to achieve that level of skill. It is always enjoyable to watch someone who loves his work and is good at it. It seems so effortless and yet that person is constantly focused on what he is doing and is paying attention to the details. The best farmers are just like that; they pay attention to the details of all that they do. So now that we have drummed that idea into you, we will share with you our details.
Telone II and Telone C-35
The big concern about methyl bromide alternatives has been how they would perform after several years of continuous usage. It has been speculated that the effects of methyl bromide last for several years and many people have predicted that after 3 to 4 years of no bromide there would be a rapid decline in soilborne pest control and crop yields with any of the alternatives. We are about to begin our fifth year of a five year study with Telone C-17 and Tillam herbicide applied prior to fall tomatoes and followed in the spring by three cropping scenarios: 1) double-cropped cucumber, 2) millet cover crop and 3) fallow. Tomato and cucumber production have been comparable to methyl bromide with Telone C-17 and Tillam in each of the four years of this study. Control of nutsedge, rootknot nematode and Fusarium wilt has been similar, as well. The pest pressure in this trial is intense and was encouraged to reach high levels prior to initiation of this study. Fusarium wilt routinely shows up in 95% of the tomato plants grown in nontreated soil each year. We have seen fluctuations in the populations of these pests from year to year, but the relative efficacy of Telone C-17+ Tillam and methyl bromide has remained fairly constant. The loss of control with Telone C-17 after a few years of no methyl bromide, which was predicted by many, has failed to materialize. Continually cropping the same land is a poor practice no matter what the fumigant program, but Telone C-17 has stood up to the test of time as well as methyl bromide. Millet is a fair cover crop, but the down side is that it becomes a better weed in successive years and is difficult to control with Gramoxone Extra (paraquat). Telone C-35 has more chloropicrin in it, so the soilborne disease control should be as good or better than Telone C-17.
When personal protective equipment (PPE) became an issue with Telone products we immediately looked for a way around this constraint and decided that broadcast application was worth investigating because it would reduce the number of affected workers to one. We looked at a lot of different equipment for broadcast application, including bigger gas knives, chisel plows, large sweeps, combinations of these with a disk, an S-tine harrow or a roller or three way combinations, but nothing seemed to be quite right until we were introduced to the Yetter Avenger coulter applicator. The deep placement provided by this equipment demonstrated its value last spring when it was so dry. Many growers had problems with nematodes in their methyl bromide treated areas, but not where Telone C-35 had been applied with this equipment. Apparently, the drier than normal conditions in drip irrigated fields resulted in the distribution of nematodes throughout the soil profile rather than primarily in the bed, and those which were deep were not exposed to methyl bromide, but did come into contact with the deeper placed Telone. The large coulter on the Yetter rig cuts through string, old plastic, and other residue which normally would hang on gas knives and be drug through the field, leaving behind poorly covered chisel traces subject to out-gassing. Additionally, the press wheels behind each gas knife do a good job of sealing the soil surface in the narrow kerf where the fumigant was applied.
The only concern we have had about broadcast application of Telone C-35, after we confirmed the superiority of the Yetter rig, has been related to soilborne disease control. We were concerned that the chloropicrin would not be held in the soil long enough at a high enough concentration in the top few inches to effectively control Fusarium wilt and other serious diseases.
Results of large plot grower trials have been very good to date, but large plot trials often do not show up subtle differences among treatments as well as small plot experiments. We are in the third continual season of small plot work related to this question and what I can tell you is this: If you have a lot of disease pressure you may find that broadcast application of Telone C-35 is not as effective as in bed application for soilborne disease control, but if your pressure is light, you probably will not see a difference. Based on all of this work, we have developed the philosophy that if you are going to apply Telone C-35 broadcast and you are concerned about soilborne disease, then you need to make an in-bed application of chloropicrin (about 130 lbs per acre) at the time of bed formation. Prior to this season, we felt that you could cut cost by just using Telone II and put your chloropicrin in the bed, but early results of one grower trial this spring are making us lean toward including the chloropicrin in both the broadcast and in-bed applications. This way you can reduce your disease pressure in the middles as well as the bed, thereby benefiting your long term disease control program.
Broadcast application was one way of reducing the impact of PPE issues, but we did not want to only have one potential option for growers. Another possibility was to attempt to develop drip irrigation application of Telone products into the bed for both first crop and double crop. Several years earlier we had tried this and had very poor results. Careful examination of results and much thought went into trying to understand why we failed when it was working in California. We felt the problem was distribution within the bed in our sandy soils, but we did not know how to deal with that. All the irrigation research conducted to date in Florida had focused on minimization of leaching rather than delivery of a pesticide throughout the bed.
Finally, we decided to investigate the movement and lateral distribution of water within the bed. The bottom line is that we found that drip delivery could work with some formulations of Telone products, if you did it right. You have to provide enough water to do the job. Not all methyl bromide alternatives perform as well when applied this way. Some form very weak gases and do not move out into the soil away from the water phase or where they were deposited by the delivery water. We feel that drip-applied Telone (1, 3-dichloropropene) does move enough to reach some of the areas of the bed shoulders not reached with other products, but even Telone will not do the job if you do not use enough water to deliver it and assure that you have firm beds to enhance lateral movement. The beauty of drip application of a fumigant is that it reduces the workers to one, it allows more flexibility in application timing, it is a closed system so it is safer for the workers, and you can do it for both first and second crops. While we are still evaluating drip applications of Telone EC and Inline (Telone C-35 EC) in small plot trials, we feel confidant that they will do the job. This will be a handy tool for double-crop producers.
While we feel that Telone products combined with chloropicrin will do the job for soilborne disease and nematode control, we recognize that the real challenge will be weed control. There are few herbicides registered on vegetable crops and even fewer that control nutsedges. Additionally, most growers are not very experienced at applying herbicides to soil, other than in row middles. Application of a herbicide to the soil in the bed introduces a certain level of risk form herbicide injury. This is where the art comes in. No one can tell you which implement to use for herbicide incorporation without knowing the exact conditions of the field, your equipment and your level of skill with that equipment. The answer to the question “how wet is the soil?” is rather subjective as are the degrees of wetness. Wet means different things to different people. What one person considers moist might be considered wet by someone else. Irregardless, we have to come up with some general guidelines for selection of incorporation implements or the grower has nothing to go on. Regardless of moisture level, a rototiller is generally thought to be the best incorporation device and a disk, the poorest. We are not sure we would endorse such a blanket statement, but it is probably a fairly accurate assessment under many circumstances. A rototiller is also the slowest implement for incorporation and requires more horsepower per foot of width than any other common incorporation implement. If the soil is overly moist or on the dry side, a disk is probably your best bet, but if the soil is moist—not wet or dry—an S-tine harrow or field cultivator can be a very effective implement and it leaves the soil smooth and ready for bed preparation. When you talk about disks, not all disks are created equal. An offset disk can be used, but a finishing disk generally does a better job and leaves the field in better condition for bed formation. Some people have used what they call a leveling disk with success, but a disk with depth shoulders on it, like a grove disk, does not mix the herbicide deep enough. Shallow mixing of the herbicide in the soil results in nontreated soil from below the mixed zone being pulled into the bed during formation. This results in erratic or poor weed control and should be avoided. You want to mix the herbicide to the depth from which you will be pulling soil to form a bed. If you form an 8 inch tall bed, then you are probably pulling 4 inches of soil which means you should incorporate the herbicide at least 4 inches deep—a little deeper would not hurt.
When do you apply the herbicide and is it necessary to roll or pack the soil after application? Time of herbicide application does not appear to be a factor in performance or injury. We conducted research on this topic and never saw a difference with Tillam injury to tomato when we applied before Telone application or afterward. We looked at everything from 3 weeks before Telone application to post application and the day before planting. We never saw any injury or differences in nutsedge control. In spite of these results, we still ‘think’ that application prior to Telone application is a good idea because the herbicide is there to control weeds in the early stages of germination rather than after germination and emergence may have begun. Some people feel that the herbicide should be applied just before bed formation so it lasts longer into the season. This is probably not a bad idea, but the Tillam label requires application 2 weeks prior to planting, so this strategy may not do you much good. The most important thing is to uniformly apply the correct rate of herbicide and assure thorough incorporation before you have a weed problem. Like most things in farming, weather will often be the deciding factor. The best rule of thumb is to do it when the soil moisture is good and when you can get to it. Regarding rolling or packing soil after herbicide application, we have looked at this and have seen no improvement in weed control as a result of rolling the soil immediately after herbicide application. The need for this is driven more by considerations for the Telone. If you apply the herbicide before the Telone, the soil will be left loose and fluffy—not the best conditions for Telone application. We have found it is helpful to have a slight crust on the soil surface when telone is applied broadcast. This crust assures some natural restriction to out-gassing. In a situation where the soil is fluffy, it is helpful to roll or otherwise pack the soil surface. If the herbicide is applied after Telone, the only reason to pack the soil would be for moisture retention or assistance in shedding water off the field. Remember that you should wait a minimum of 7 days after Telone application before disturbing the soil. In some situations, like overly moist soil, it pays to disk the field after Telone application in preparation for bedding so the Telone comes out of the soil better and the soil is in a better state for bedding. This is a case where herbicide application and incorporation after Telone application would save one operation in the field and might be a good reason for applying the herbicide at that time.
Up until now, we have focused on soil incorporated herbicides, but not all herbicides have to be incorporated. The decision to incorporate is based upon the volatility of the herbicide (and the label requirements) and the necessary depth of weed control. Tillam, Treflan and Trilin are all very volatile herbicides which must be incorporated to achieve weed control, but Devrinol can go either way. If you are trying to control nutsedge or other weeds capable of emerging from depths greater than about one-half inch in the soil, you need to incorporate Devrinol to that depth. If you are targetting small seeded annual weeds, you can just spray Devrinol on the surface of the soil in the bed prior to covering with plastic. Since nutsedge can emerge from deep with-in the bed, you need to make sure all of the bed soil is treated. Tillam has provided fair to excellent control of nutsedge in small plot and grower scale trials. Treflan does nothing for nutsedge, except make it easier to see by controlling most of the other weeds. We have had mixed results with Devrinol; sometimes we get some nutsedge control with it and other times we don’t see it. Combinations of Tillam with Treflan or Devrinol have performed well as have tank mixes of Treflan and Devrinol. If you use a combination which includes a volatile herbicide, then you have to incorporate it into the soil.
Other tricks or tips that add to the art of herbicide application include such things as adjusting the set of the blade gangs on a disk to get good mixing and operating the implement at the correct speed. If you look in the manual which came with your implement, there is often a recommended ground speed for operation. Six mph is a good rule of thumb for disks and field cultivators. Some operators don’t like to go that fast because the ground is rough and they don’t like to bounce. As a result, you need to supervise your operators closely to assure they are doing the job properly. If you operate too slowly, mixing suffers and you may end up with hot streaks in the bed. These concentrated areas of herbicide often result in crop injury. Make sure you have adequate, but not excessive, spray overlap and that you do not pull untreated soil from the ditch edges into the beds. Most importantly, don’t forget to pay attention to the details.
What if there is no herbicide labeled for your crop which will control the weeds you expect? What if you double-crop and need additional weed control in the bed for the second crop? This may be a good place for Vapam or K-Pam. There has been considerable research conducted in Florida and elsewhere with metam products, including Vapam and K-Pam, and the biggest problem has been consistency of results. Many different application procedures have been investigated and we know a lot more about what does not work than what works. What we do know is this; soil incorporation with a rototiller followed by sealing the soil surface with a power roller appears to make a big difference in performance. However, using this procedure on a broadcast basis can lead to exposure problems. Still, the fact that it seems to work with some consistency makes this procedure worthy of additional investigation with some modification. The big plus for Vapam an K-Pam is the fact that they are the only currently registered alternative fumigants which provide nutsedge control. There are a number of crops where they may have a fit for this very reason. An even better fit for Vapam and K-Pam is for control of established weeds or propagules, like seed and tubers, in the plant bed for double-cropping because they can be delivered through the drip irrigation tubing. Prior to our recent investigations of water movement in the bed, drip delivery of fumigants was a hit or miss proposition. Now we have a much better understanding of what it takes for proper delivery of products like Vapam and we have seen improvements in consistency and efficacy, as a result.
Mulch Film Technology
One area of change that has potential for today and perhaps the future, is the development of virtually impermeable film (VIF) mulch. VIF mulch looks similar to our standard low density polyethylene film mulch (LDPE), but it has some unique properties. VIF mulch is much more retentive of methyl bromide and, as a result, bromide rates can be reduced considerably without sacrificing efficacy. This property can be used to advantage by maintaining pest control with less methyl bromide as prices increase and availability declines. However, there is a down side: VIF does not stretch and some of it can be more challenging to lay than LDPE mulch. Not all VIF mulches are the same. There are differences in methyl bromide retention and in handling properties. Some films are prone to shear linearly. Some growers have problems laying a given VIF mulch and others do not have any problem at all. It appears to be related in some part to the equipment and how it is adjusted. While VIF was originally proposed as a means of reducing out-gassing of methyl bromide in an effort to stop the elimination of methyl bromide as a soil fumigant, it has not achieved its goal in the U.S.A. and is seen more as a means of rate reduction to reduce fumigant costs and maintain efficacy of methyl bromide. Only recently has it been investigated with Telone products to see if it effects Telone performance. Results of preliminary trials suggest that it does as a result of maintaining a higher concentration in the bed for longer. While not important for broadcast applications of Telone products, this could be especially important for drip delivery of Telone EC and Inline in beds where resurgence of nematodes during a double-crop can be a significant problem. Better containment of fumigants will be even more important in the future as concerns about atmospheric pollution become more widespread.
The future of vegetable production in Florida is similar to its past in that change will come and success will come only to those who pay attention to the details and embrace the changes as opportunities. Methyl bromide represented a big change for vegetable and strawberry growers and the change did not come overnight. It required the development of new equipment and modifications of existing production practices as well as grower education and a willingness to change. The future is no different.
Mention of a proprietary products does not constitute an endorsement by either the authors or the University of Florida. As always, use pesticides with care and as directed by the label.
Jim Gilreath et al
May 22-23, 2002
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In the search for an alternative pest management system to that of methyl bromide, it was quickly recognized that herbicide combinations to provide broad spectrum weed control would be a critical component of the new system. Although herbicides are currently viewed as a vital component of the new system, some undesirable outcomes have also been observed such as herbicide induced crop injury, herbicide resistant weeds, and frequently small but increased weed densities and changes in weed spectrum compared to the weed control provided by methyl bromide. Similarly, recent changes in methyl bromide-chloropicrin formulation and reduced application rates have seemingly contributed to problems of increased weed density and diversity in the field. New weed problems will continue to evolve and present challenges for growers, as well as university extension and research scientists. For example, we have observed how failure to adequately manage weeds within the field can not only effect crop yield, but serve as alternative hosts to nematodes, causing potential for additional crop production problems.
Beginning fall 2001, field studies were initiated in south-west and west-central Florida to evaluate the host status of various weeds to root-knot nematode (Meloidogyne spp.). Weed roots recovered from the field were returned to the laboratory and stained with a special vital stain to ‘light-up’ the egg masses of the root-knot nematode adhering to roots. The relative density of egg masses per gram of weed root were characterized according to an indexing scale of 0 = no egg masses; 1 = light or <10 per gram of root; 2 = moderate or 10-50 / gram root; 3 = heavy or 50-100 / gram root; and 4 = very heavy or >100 egg masses per gram of root.
The results of these three preliminary field surveys clearly showed the excellent host status to root-knot nematode of many common weed species found in agricultural fields. These common weeds included various species of pigweed, purslane, nightshade, eclipta, Carolina geranium, Gnaphalium, and a number of legumes such as sesbania, sand vetch, and clovers. Somewhat surprisingly, even the grasses, including various species of crabgrass and goosegrass served as hosts, albeit relatively poor hosts, to rootknot nematode. In general these results would suggest that nematodes cannot be effectively managed unless weeds are also effectively and simultaneously managed in the field. Weeds which are allowed to grow and increase in numbers, particularly in-between mulch covered rows, serve to increase soil population densities of nematodes and perpetuate the nematode problem from one cropping season to the next, and quite possibly, mandate the continued need for broad spectrum soil fumigants for nematode control.
Post-plant Crop Rescue
As the phase-out of methyl bromide continues, and rates, formulations, and use of alternative pest management tactics change, the number of nematode problematic fields has also changed. In fact, the number of grower fields in which root-knot nematode has become a serious problem within the established crop has increased in recent years. Once the discovery is made that nematodes have colonized root system and stunted plant growth, the question is whether it is possible to effectively reduce nematode population levels and restore crop yield potential. At present the only post plant nematicide which can be used to help resolve an established nematode problem is Vydate (Oxamyl). Field observation of crop rescue attempts with Vydate injections via the irrigation system have usually demonstrated some improvement to plant growth and vigor, but not necessarily yield. Many factors simultaneously interact to influence the extent to which plants respond to Vydate treatment. Not all factors are well understood at this time, and field research efforts continue to evaluate new strategies of Vydate use to maximize nematode control and crop yield response.
During Fall 2001 and Spring 2002, crop rescue studies were again conducted to evaluate new chemigational strategies for postplant Vydate use in tomato. In general, the experimental objectives were to compare nematode control and tomato yield in treatments receiving up to three Vydate application per week, applied either during the first 6 weeks, last 6 weeks, or the entire 11 week tomato cropping season. In general, the experimental results of these trials evaluating Vydate use as a postplant, crop rescue treatment for nematodes indicated the following:
Fields with previous history of nematode problems should be closely monitored after transplanting. The sooner a nematode problem is identified in the field and the sooner Vydate treatments are initiated, the greater the response in plant growth and yield will be. Clearly the nematode problem and impact to crop yield will intensify over time if nothing is done, particularly if the plant undergoes periods of moisture stress.
Regardless of the time of discovery in the field, roots which are heavily galled are not likely to respond satisfactorily (stage a dramatic comeback) to Vydate treatment.
Split applications are superior to single applications, ie., Vydate applied three times per week was better than a single application per week.
Repeated weekly applications throughout the entire growing season was superior to either early or late season Vydate treatment application regimes.
Post Harvest Crop Destruction:
One of the foundation principals of an integrated nematode management strategy is to ensure early destruction of the crop immediately after final harvest. The major objective is to remove the plant food source which maintains nematode reproduction and soil population growth. Any delay in crop termination can increase soil populations of nematodes, particularly in the span of a few weeks after final harvest if the plant and its roots are not killed immediately. In general, the more nematodes left in the soil after a crop, the more which will survive to infect roots of the following crop, and the more difficult it will be to achieve satisfactory nematode control with any preplant fumigant. Clearly, the opportunity to enhance nematode control with soil fumigation and minimize losses in crop yield due to nematodes is dependent upon the adoption of early crop destruction after final harvest.
Field research efforts continue to explore the
chemigational use of water soluble fumigants such as metham sodium (Vapam),
metham potassium (Kpam), and Telone EC for crop destruction and nematode
management. Recent field trials in south-west and west-central Florida
have all demonstrated the feasibility of the approach. For example,
Telone EC (5-15 gal/treated acre) was evaluated at four locations for sting
or root-knot nematode control and for post harvest crop destruction purposes.
In these trials, Telone EC significantly reduced nematode populations and
provided near complete mortality of plants within treated rows. Results
of field trials performed during Spring 2002 have also clearly demonstrated
the ability to kill tomato, pepper, and strawberry foliage via destruction
of roots. Soil populations of nematodes also were substantially reduced
in the trials.
After the phase-out of methyl bromide, the imperfections of any alternative pest management system will be expressed as higher end of season disease, weed, and nematode population density. Given that these new systems are also generally more performance sensitive to differences in grower application methodology and cultural practice, soil type, and prevailing environmental condition, even early season nematode problems are expected to increase in frequency and intensity. As a result, continued development of IPM, postplant crop rescue, and post harvest crop destruction strategies to minimize potential crop yield impacts are needed.
J.W. Noling & J.
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|H—The relative density of root knot nematode (Meloidogyne spp.) egg masses per gram of weed root were characterized according to an indexing scale of 0 = no egg masses; 1 = light or <10 per gram root; 2 = moderate or 10-50 per gram root; 3 = heavy or 50-100 per gram root; and 4 = very heavy or >100 egg masses per gram of weed root.|
LPE provides an entirely new mode of action to accelerate ripening and extend shelf life, says Dr. Timothy Peoples, director of research and development at Nutra-Park. Depending on the crop LPE effectively increases marketable yield and uniform color development and improves fruit quality.
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