The Vegetarian Newsletter:
A monthly newsletter featuring timely information on Florida’s vegetable and fruit crops
Hydrogen cyanamide may advance ripening date in Florida blueberries
Jeff Williamson, Horticultural Sciences Department, IFAS, University of Florida, Gainesville, FL
New blueberry plantings continue to be established in Florida. Many of these plantings are relatively small and are often managed by growers with little or no experience in commercial blueberry production. New blueberry growers with limited experience may not be aware of hydrogen cyanamide or the potential benefits and limitations of its use. The following discussion is based on years of experimentation, experience, and observation and attempts to summarize what we’ve learned about using hydrogen cyanamide in commercial blueberry production in Florida.
Hydrogen cyanamide (Trade names Dormex, BudPro and Krop Max) is classified as a plant growth regulator and is used to promote uniform budbreak on a variety of deciduous perennial fruit crops including blueberry. It is also a restricted use pesticide with specific requirements for its safe and legal application including very specific requirements for protective gear and specialized spray equipment (i.e. enclosed tractor cab). Most Florida blueberry growers who produce for the early-season fresh fruit market will want to consider using hydrogen cyanamide; growers who may not be interested in this product include organic growers, u-pick, rabbiteye, and other small locally-based growers who are not targeting the early market, and growers who use an “evergreen” or “non-dormant” production system. Growers who are considering using hydrogen cyanamide should first become familiar with the products’ label and the requirements and restrictions therein. Small-acreage growers who do not have the expertise or equipment necessary for proper application may find it easier to have hydrogen cyanamide custom-applied by a certified professional pesticide applicator who has experience with this product.
In Florida, hydrogen cyannamide is used primarily to advance the blueberry harvest season. Although highly dependent on cultivar and weather conditions, hydrogen cyanamide can potentially advance ripening date of some cultivars by a week to 10 days. In a highly volatile, early-season market, these few days can mean the difference between economic success or failure. Earlier berry ripening date is achieved by a strong vegetative flush in early spring as a result of hydrogen cyanamide applied during the pre-bloom period. Other factors being equal, earlier and greater canopy development in the early spring translates to faster fruit development and earlier berry harvest. There is also some evidence to support slightly larger average berry size, again likely due to an increase in leaf to fruit ratios during the berry development period. Some flower bud thinning can occur in certain situations leading to further increases in berry size and earliness at the expense of total yield.
Application rate and timing are critical factors that directly impact efficacy. Hydrogen cyanamide is applied during the dormant season after as much winter chilling as possible has been received but before flower buds pass beyond stage 2 (swollen buds with closed bud scales) of development (Figures 1 and 2). This is approximately 30 or so days before bloom and is usually between December 20 and January 10 in north-central Florida. Improper timing can result in poor efficacy and/or damage to flower buds. It is important not to apply hydrogen cyanamide too early in the winter, because tissue that is not fully dormant is subject to injury and lack of pre-chilling seems to reduce efficacy. On the other hand, flower buds that have developed past stage 2 are at increased risk to spray injury. Reports of injury or ineffectiveness from hydrogen cyanamide treatments are more common in central Florida where less winter chilling occurs prior to treatment than in north-central Florida. These reports are also more common following unusually warm winters than after normal or cold winters when more chilling occurs prior to spray applications.
Suggested application rates vary somewhat among the product labels. The Dormex label specifies a rate of between 1.5 and 3.0 % (v/v) of formulated product while the BudPro and Krop Max labels specify a rate of 1.5% (v/v). The higher rates for Dormex are suggested to aid in burning off last year’s foliage if desired. However, the potential for crop injury is increased at higher rates (see Dormex label for rate precautions). All three products recommend use of a non-ionic surfactant at rate not to exceed 0.5% (v/v). Research and experience in Florida has shown that as hydrogen cyanamide spray concentration increases, so does the potential for flower bud injury. This response is somewhat dependent on cultivar, weather conditions, and pre-chilling conditioning. A safe, and effective rate for most situations appears to be 1.5 % (v/v) of formulated product.
Susceptibility to flower bud injury can vary greatly among cultivars. Generally ‘Sharpblue’ (now obsolete), ‘Windsor’, and ‘Primadonna’ have shown greater than average susceptibility to flower bud injury. ‘Emerald’, ‘Star’, and ‘Jewel’ have generally responded well to hydrogen cyanamide sprays in north-central Florida. However, there have been some reports of injury to ‘Jewel’ in central Florida, especially following mild winters. Many of the newer cultivars have not been thoroughly tested under a variety of different conditions to fully evaluate their sensitivity to hydrogen cyanamide. When in doubt, any cultivar should be thoroughly tested for phtotoxicity at the location, and under the conditions that it is being grown, before treating large numbers of plants.
Preconditioning in the form of exposure to chilling temperatures appears to reduce susceptibility to flower bud injury from hydrogen cyanamide. This relationship can be seen in Table 1 which shows the incidence of flower bud mortality at different rates of hydrogen cyanamide for plants exposed to varying amounts of pre-chilling temperatures. The greatest flower bud mortality was at the highest spray concentration with plants that had no pre-chilling conditioning. Moreover, at either spray concentration, the level of flower injury decreased as pre-chilling increased. This is strong evidence that at least some of the injury from hydrogen cyanamide observed in central Florida following mild winters is due to lack chilling temperatures prior to application.
Experience has shown us that thorough coverage is required for good treatment responses. Spray volumes of 50 to 100 gpa are called for by product labels and are usually needed for thorough coverage in typical Florida blueberry fields. Growers should keep in mind that growth regulators can be erratic and somewhat unpredictable in their response because many uncontrolled and/or unknown factors can interact with their efficacy. However, some conditions that will work in favor of a predictable hydrogen cyanamide response are: 1) fully dormant plants that have accumulated chilling prior to treatment; 2) good candidate cultivars (high yield potential and/or poor natural spring leafing that are not highly susceptible to spray injury; and 3) proper spray timing, concentration, and coverage.
Table 1. Effects of Dormex spray concentration and pre-chilling on flower bud mortality (%) of ‘Misty’ blueberry.
Spray conc. (%) z | Chilling (hrs.) | Linear sig. | ||
0 | 150 | 300 | ||
0 | 1 | 2 | 1 | ns |
2 | 20 | 11 | 2 | *** |
4 | 38 | 26 | 19 | * |
Significance | ||||
Linear | *** | *** | *** | |
Quadratic | ns | ns | ** | |
R 2 value | 0.63 | 0.78 | 0.79 | |
Taken from HortScience 36:922-924.
ZSpray concentration of formulated product.
Implications of the Food Safety Modernization Act on Florida Fruits and Vegetables
Michelle Danyluk1, Renée Goodrich Schneider2, Mark A. Ritenour3 and Keith Schneider2
1University of Florida, Citrus Research and Education Center, Lake Alfred, FL
2Food Science and Human Nutrition, Gainesville, FL
3University of Florida, Indian River Research and Education Center, Ft. Pierce, FL
Food Safety Modernization Act and its Potential Impact on the Fresh Produce Industry
In January 2011, the Food Safety Modernization Act (FSMA) was signed into law, representing the most significant change in food safety requirements since the enactment of the original Food Drug and Cosmetic Act in 1938. The Food and Drug Administration (FDA) is responsible for ensuring the safety of nearly all food products in the US with the exception of meat and poultry, which falls under the jurisdiction of the US Department of Agriculture (USDA). FSMA grants the FDA a number of new powers (e.g., mandatory recall authority) and requires them to create more than a dozen rules and at least 10 guidance documents, as well as a number of other responsibilities This article summarizes FSMA and its potential impacts on the Florida fruit and vegetable industries.
Overview of FSMA
The overall theme of FSMA is to build a new system of food safety oversight which focuses on applying common sense and the best science available to prevent foodborne outbreaks. This is a fundamental shift in fresh produce food safety legislation, away from reactionary responses to foodborne illness outbreaks, and towards preventative measures that are risk-based and built into the entire food system.
Prevention-based programs are not new to FDA. Hazard Analysis Critical Control Point (HACCP) programs for seafood, juice and eggs (regulated by FDA), for meat and poultry (regulated by USDA), and used by numerous others in the food industry are tangible examples of how preventative-based food safety programs can work. What is new about FSMA is its expanded use and focus on the farm-to-fork approach. It recognizes that breakdowns in food safety systems at any point during food production, processing, transportation and retailing can lead to foodborne outbreaks, which in turn can lead to consumer distrust and economic loss. The Tester Amendment to FSMA exempts small farms and business operations from some food safety requirements; however, substantial documentation will be required to qualify as a small farm or business.
New inspection and enforcement tools for FDA are also included under FSMA. The FDA, with state partners and third party companies (registered with FDA), will conduct more frequent inspections to verify that preventative controls are implemented. This will include increased access to food safety plans and records required to document their implementation. Within the prevention framework, facilities that are judged to be “higher risk” (yet to be defined) will be targeted for more frequent inspection (once in the first five years, and every three years thereafter). “Low risk” facilities will be required to be inspected once in the first seven years and every five years thereafter. Failure to comply with a voluntary recall of unsafe food will result in a mandatory recall issued by FDA.
FSMA also has provisions that ensure imported food is as safe as domestic food. Currently about 15% of the food consumed in the US is imported (20% of the produce and nearly 80% of the seafood). The FSMA mandates that importers verify that the required preventative controls are in place in foreign food facilities that export food to the US. If a foreign food facility does not permit an FDA inspection, FDA can refuse the importation of that food.
Impacts of FSMA on Florida Fruit and Vegetable Growers and Packers
One of the FSMA objectives is a proposed rule to ensure the safe production, harvesting and packing of fresh produce. This change of FDA’s authority to ‘before the farm gate’ is an example of how FSMA is integrating a farm-to-fork, preventative programs approach.
FDA held a number of listening sessions and toured farms and packinghouses (including a number of operations in Florida in March 2011) to gain insight into production and packing processes. Working groups at FDA are currently completing the proposed produce safety rule. They expect to publish a proposed rule by the end of 2011, followed by a comment period. It is expected there will be specific regulations for some commodities that are considered by FDA to be high risk (e.g., leafy greens, tomatoes and melons). For other commodities, there likely will be a less specific umbrella regulation. Each operation will be responsible for implementing the necessary procedures and systems once the specific minimum standards are published in the rule.
While FDA has not previously been fully authorized to regulate produce production, it has issued guidance related to food safety and production practices that can give us a clue as to where the produce safety regulation will head. Guidance given in the original 1998 Good Agricultural Practices (GAPs) guide (The Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables) has been used for the development of many food safety and GAPs programs and likely contains many of the key principles to the produce safety regulation. Additionally, a collaborative project between FDA, USDA and Cornell University, called the Produce Safety Alliance (PSA), has been created. The overall goal of PSA is to develop and provide training and educational opportunities related to current best practices and guidance, and future regulatory requirements. PSA consists of food safety experts from many of the top universities from around the US. PSA is currently developing a nationwide curriculum to increase the understanding of the principles of GAPs and to facilitate the implementation of food safety practices on fresh fruit and vegetable farms and in packinghouses. Visit producesafetyalliance.cornell.edu/psa.html for more information or if you are interested in working with PSA on the curriculum development or other objectives.
It is important for Florida’s fresh fruit and vegetable industry to stay informed about proposed rules and guidance that are developed as a result of FSMA and to be active in providing feedback during the comment period. For the most current information and details about FSMA, visit www.fda.gov/FSMA. This site also provides a way to sign up to receive FSMA updates via e-mail. Remember, active industry collaboration and comment on FDA proposed rules and guidelines will result in regulations that are commercially viable while increasing consumer safety and confidence in the food they buy.
Use of Soil pH Amendments for Leafy Greens Production in South Florida
Alan L. Wright1, David D. Sui2, Calvin Odero1, and Huangjun Lu1
1Everglades Research & Education Center, Belle Glade, FL
2Palm Beach County Extenstion, West Palm Beach, FL
Soil subsidence in the Everglades Agricultural Area (EAA) began when the organic soils (Histosols) were drained. When these soils were first drained, pH values were much lower than at present, typically in the range of 4.5 to 5.5. In contrast, the current range for the shallow muck soils of the EAA is 6.5 to 7.5, although pH is spatially variable. Due to tillage operations for bed preparation, weed control, incorporation of fertilizers, and planting, particles of calcium carbonate are transported from the subsurface into the root zone of the surface soil. Also, carbonates dissolved in water can move up in the soil profile due to evapotranspiration, and are often deposited at or near the soil surface.
The result of these factors is that the pH of shallow muck soils increases through time, which exerts a negative effect on nutrient availability to crops, particularly for micronutrients. The use of amendments to decrease soil pH and increase nutrient availability is being investigated. We tested different commercially available soil pH amendments to determine their effectiveness for the shallow calcareous muck soils where most of the leafy greens production in south Florida is based. These amendments have been shown to be effective in reducing soil pH in other parts of the country and for other soil types. However, site-specific information is needed to accurately gauge their efficacy.
Romaine and iceberg lettuce are grown on about 10,000 acres in the EAA resulting in about $60,000,000 in revenue annually (Fig. 1 and 2). Due to its short duration in the field (about 60-70 days), it is very sensitive to deficiencies in nutrients. Thus, nutrient and fertilizer management is increasingly critical. Due to rising fertilizer costs, there is interest in evaluating alternative strategies for providing nutrients to crops.
The amendments tested include elemental sulfur, ferrous sulfate, and aluminum sulfate. A wide range of application rates from 0 to 2000 lb/acre were tested to ensure a response either in terms of yield increases or increases in concentrations of plant-available nutrients (Fig. 3). Application methods tested include a broadcast application and a banded application. Broadcast applications consisted of surface application of the materials followed by bedding. Banded applications were made in 4-inch wide bands across each plant row in each bed. The concept is that less material, and thus lower input costs, would be needed if the materials are applied only where the most benefit could be attained, i.e. the plant row.
Fig. 1. Romaine lettuce grown in the Everglades Agricultural Area.
A significant yield response of romaine lettuce to all pH amendments occurred for both application methods. The amendments generally produced similar responses in terms of romaine yield. Banded applications of elemental sulfur and ferrous sulfate at 250 lb/ac produced the optimal romaine yield, but 500 lb/ac of aluminum sulfate was needed to produce the highest yield. In contrast, for all amendments, 500 lb/ac produced the optimal yield when the amendments were broadcasted. Thus, it is apparent that banded application was a better option than broadcasting. However, at higher application rates (>500 lb/ac), broadcasting produced higher yields than banding. This result was likely attributed to stunted early growth and establishment caused by high banded application rates concentrated in the plant row.
Elemental S addition has been shown to increase nutrient availability in the short term (Ye et al., 2010a,b), which coincides with the shorter growing season of leafy greens. This increase in nutrient availability, including P and micronutrients (Ye et al.., 2010a,b) by S application stimulated the growth and increased yields of romaine lettuce. A similar function by the other two amendments also reduced pH in the short-term, which likely increased nutrient availability to lettuce. Thus, these amendments may have a place in grower management plans for leafy greens, but the economic costs and benefits of using amendments compared to traditional fertilizers is necessary.
References:
Ye, R., A.L. Wright, W.H. Orem, and J.M. McCray. 2010a. Sulfur distribution and transformations in Everglades Agricultural Area soils as influenced by sulfur amendment. Soil Sci. 175:263-269.
Ye, R., A.L. Wright, J.M. McCray, K.R. Reddy, and L. Young. 2010b. Sulfur-induced changes in phosphorus distribution in Everglades AgriculturalArea soils. Nutr. Cycl. Agroecosys. 87:127-135.
New Strawberry Released
by Vance M. Whitaker
In April, 2011 the ‘FL 05-107’ strawberry was released through the IFAS cultivar release committee (Fig. 1). This achievement was the result of work by several faculty members from IFAS and other institutions. The cultivar was jointly released by breeders Dr. Vance M. Whitaker and Dr. Craig Chandler. Dr. Natalia Peres and Dr. Bielinski Santos performed disease screening and horticultural evaluations respectively. Dr. Charlie Sims provided flavor and postharvest evaluations along with Dr. Anne Plotto (USDA-ARS, Winter Haven) and Dr. Cecilia Nunes (USF Polytechnic-Lakeland). Dr. Kevin Folta also provided DNA marker data.
Figure 1. ‘FL 05-107’ tested in a high-tunnel environment during the 2010-11 season.
During the 2010-11 season, UF cultivars ‘Strawberry Festival’ (2000) and ‘Florida Radiance’ (2008) comprised 50% and 20% the approximately 9,000 acres in Florida respectively. ‘FL 05-107’ combines the early yield of ‘Radiance’ with some of the plant durability and post-harvest qualities of ‘Festival’ and is expected to find a niche in the industry. Yields and fruit size of this new cultivar are comparable to ‘Radiance’.
‘FL 05-107’ has a few unique aspects compared to recent UF strawberry releases. During the 2009-10 season ‘FL 05-107’ had an average sugar/acid ratio of 13.1-14.5, which is significantly higher than that of the current cultivars and results in a distinctively sweet flavor. In addition, the external color of the fruit does not darken significantly as temperatures rise, maintaining its attractive appearance throughout the season. It also has a more compact plant architecture, possibly allowing for greater planting densities.
Large-scale commercial trials totaling approximately 400,000 plants will be conducted beginning in fall, 2011 with full commercial availability by fall, 2012.
CENTRAL FLORIDA FARMER’S MARKETS
By Dr. Richard Tyson, Extension Agent IV, rvt@ufl.edu
There are over 20 farmer’s and community markets in and around the Orlando, FL area. These markets are open one day each week with some evening market venues. Given the market schedules it would be possible to sell products every day of the week except Tuesdays in Central Florida. The downtown Lake Eola market and several of the evening markets combine festival style events such as beer fests that can really liven up the venue.
Farmer’s markets provide an opportunity for small farmers and market gardeners to sell their fruits and vegetables, herbs, plants, and related products and advertise themselves and their businesses to the general public. Most long term successful vendors have off market sales to restaurants and food coops specializing in locally grown products with some utilizing on-farm consumer supported agriculture. Thus contacts made at the markets can often lead to additional opportunities. Farmer’s and community markets have a number of advantages and disadvantages.
Some advantages are:
- Usually no long term contracts are required which allows marketers to sell seasonal produce without the infrastructure commitment required for normal businesses operating year-round.
- They provide a place for networking that can lead to off-site sales during other times of the week to restaurants, grocery stores, roadside markets or to the general public.
- They provide an outlet for the sale of off-grades of produce which the general public will purchase but cannot be sold to restaurants or grocery stores which usually require the highest visual quality produce.
Some disadvantages are:
- Marketers must comply with the rules and requirements of the markets which may vary depending on the jurisdiction (county or city) and the market manager’s own preferences.
- Weather in Florida can be unpredictable and putting up with adverse conditions at open air markets which reduces turnout can be expected from time to time with subsequent variability in income.
- Loading and unloading produce, plants, and farm products can be physically demanding and requires able bodied individuals.
Before committing to a farmer’s market, its best to spend several days there gauging the size of the crowd and their willingness to purchase products. Look for vendors selling similar products that you may offer. Don’t make long term commitments unless you are certain a particular market will be a good fit. For more information about farmer’s markets in the Orlando area, contact the market managers supervising the individual markets listed below.
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2012 Fresh Vegetables Outlook
John J. VanSickle, Professor of Food & Resource Economics Dept., UF/IFAS
The fruit and vegetable industry has often been the focus of U.S. policy makers in charge of nutrition programs to encourage consumers to eat more of our product for diet and health purposes. We might question the success of those programs given the apparent decline in demand that has occurred over the last 10 years. Figure 1 shows the per capita consumption trends for fresh, frozen and canned vegetables from 1980 through a predicted consumption level for 2011. It is troubling that from 1970 to 2000 vegetables enjoyed a boom in consumption and offered plenty of opportunity for those growers producing for the U.S. market. Since 2000, the market has been declining (figure 2). This decline in consumption growth cannot be attributed to the decline in the economy that started in 2008. This decline in consumption started long before the recession of 2008-09. So what is responsible for the decline in demand? Demand is driven by two primary factors, population and income. The U.S. Bureau of Census reports that U.S. population grew 9.7% over the decade from 2000-2010. That growth implies that our market grew 9.7% if per capita consumption stayed the same. Per capita consumption for fresh market vegetables (excluding potatoes, sweet potatoes, dry peas and lentils and dry beans) actually fell 2.8% while canned and frozen vegetables declined 2.9% and 4.2%, respectively. Overall, per capita vegetable consumption including potatoes, sweet potatoes, dry peas and lentils and dry beans, fell 7.1% since 2000.
Part of the means to survival in the vegetable business comes from being able to increase prices when costs go up. The producer price index (PPI) measures the cost of growing vegetables relative to a base period which is 1982 for figure 3. The cost of producing vegetables increased significantly over the decade of the 2000’s, especially the early half of this decade. The producer price index for vegetable growers increased 29.6% in the 2000s relative to the 1990s. The price received index (Price) in figure 3 is a similar measure for the unit value received by growers of fresh vegetables relative to the base period of 1982. Price increased only 28% in the 2000s, meaning growers lost ground since calendar year 2000 relative to returns in the 1990s. As if that was not enough, demand in the 2000s also declined, meaning growers were not offsetting increased costs with larger markets or increased prices.
What the data do suggest is that consumers are shying away from vegetables as prices increase. Figure 4 shows the per capita consumption of vegetables since 2000 compared to the consumer price index for vegetables. It is noteworthy that we have seen a decline in consumption as prices have increased. We have not had the luxury of an expanding demand to offset the higher costs experienced by growers. Consumers are backing away from vegetables as prices increase.
What is the outlook for Florida vegetable growers? Policy makers recognize the benefits to consumers eating more whole grains and fruits and vegetables. The USDA ChooseMyPlate program (http://www.choosemyplate.gov/) calls for increases in consumption of fruits and vegetables, telling consumers to make half their menu out of fruits and vegetables. At the same time, concerns over food safety and sustainable production practices have increased costs to U.S. growers more than to our international competitors. Imports are securing an ever increasing share of the U.S. market for vegetables, accounting for 24.3% of the U.S. market for fresh vegetables in 2010. Those increases in market share are at the expense of U.S. growers who command less of a shrinking market for fresh market vegetables. Increasing costs in the face of increasing imports have created difficulties for U.S. growers. Increasing costs have also resulted in increased prices to consumers, pricing many consumers out of the market for fresh fruit and vegetables.
Markets need to return growers to the better times growers experienced prior to calendar year 2000. Grower profit margins are likely to get squeezed further before we see consumers regain their desire for fresh fruit and vegetables and grow this market. We have to get a handle on increasing costs in order to hold the line on consumer prices and grow the demand structure for vegetables. Until production costs can be better controlled, growers will continue to struggle to stay in business. That is not likely to change in the near future barring some type of production disaster experienced in some competing area of the world. Research and development needs to be increased for purposes of controlling costs and increasing demand. The last 10 years have seen increasing prices for vegetables stem any possible growth in consumption that might have occurred. There are pockets of success in the industry. Some of those include blueberries, peppers and fresh tomatoes other than field grown large round tomatoes. As we move into writing a new Farm Bill in 2012, policy makers are likely to cut budgets for many farm programs to bring more fiscal responsibility to the Federal government. If that translates into fewer dollars for research and promotion for vegetables, then this tide of declining returns is likely to continue over the longer term. The advantage this industry holds is that diet and health concerns have led to a call for increased consumption of fruits and vegetables. But consumers are becoming more cost conscience as threats on our economy persist. A recovery in our economy will help the demand for vegetables, but true recovery will require more. It will require more efficient producers with even better products.
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