Policies and regulations can impact a farmer’s ability to make a living. The 2020 Florida, Georgia and Alabama legislative sessions have officially wrapped up, and the June issue of VSCNews magazine will tell readers how agriculture fared in each state.
Adam Basford, director of state legislative affairs for Florida Farm Bureau, discusses the successes and progress that has been made this legislative session.
Mary Ann Hooks, director of governmental affairs with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), gives an update on how the UF/IFAS budget fared this year.
Georgia Lawmakers pressed the pause button on the 2020 legislative session due to COVID-19.
Georgia Agribusiness Council President Will Bentley discusses the Ag bills that were still in play when the session paused.
Furthermore, Ashley Robinson, AgNet Media communications intern, dives deeper into the Alabama session based on an interview with Leigha Cauthen, executive director of the Alabama Agribusiness Council.
Farmworker safety is also highlighted in the June issue. Amy Wolfe, president and CEO of AgSafe, discusses precautions that farm owners and managers should implement to ensure the safety of their farmworkers as the industry navigates through the COVID-19 pandemic. However, Wolfe warns not to trade out one risk for another. On top of additional COVID-19 precautions, growers shouldn’t overlook other tried-and-true general farm safety measures.
Hemp interest is still strong in the Southeast. Clint Thompson, AgNet Media multimedia journalist, looks at the impacts of COVID-19 on the hemp industry. Thompson also addresses the rules and regulations for producing hemp in Florida, Georgia and Alabama.
Lastly, Jaya Joshi, a postdoctoral associate at UF, discusses the future of meeting the demand for meat with plant proteins. According to Joshi, there is rising interest among consumers who want to eat less meat and dairy and more fruits and vegetables without compromising their protein intake. Plant-based protein may be the answer for these individuals.
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Since its first detection in 2008, spotted-wing drosophila (SWD) has emerged as a devastating pest of berry and cherry crops throughout the United States.
IDENTIFICATION AND DEVELOPMENT
Male SWD have dark spots on the outer margins of their wings. Female SWD have saw-like ovipositors used to cut the skin of ripe or ripening fruit and deposit eggs inside the fruit (Figure 1).
Figure 2. Spotted-wing drosophila damage progression in blueberry
Larvae feed inside the berries and develop through three stages within the fruit, causing it to degrade (Figure 2). Larger larvae are visible to the naked eye, and if they are detected in the fruit, distributors may reject contaminated loads of fruit. SWD injury also increases the risk of damage by other pests and fungal infections.
In regions with mild winter climates (e.g., Georgia, Florida and California), SWD adults can be captured in traps year-round and can infest ripe fruit. Females lay over 300 eggs that develop to adult flies in eight to 10 days during the growing season, completing several generations per year (Figure 3). High populations build up over a short period of time. A wide host range, fast generation time, ability to lay eggs directly into the fruit, and larvae being sheltered from insecticide applications while feeding inside the fruit make this pest a challenge to manage.
Figure 3. Spotted-wing drosophila life cycle
CONTROL COMPONENTS
A multi-regional team of researchers I lead has investigated behavioral, cultural, biological and chemical strategies to effectively control SWD. This team was funded by the U.S. Department of Agriculture National Institute of Food and Agriculture through the Organic Agriculture Research and Extension Initiative (Project # 2015-51300-24154 and 2018-51300-28434). Based on the team’s findings, SWD control programs should consist of three major components: 1) monitoring and identification, 2) preventative tactics such as exclusion, sanitation, frequent harvest intervals, pruning, mulching and resistant varieties and 3) curative tactics such as the judicious use of insecticides.
While a number of insecticides provide good SWD control in conventional production systems, organic management of SWD is really challenging. However, the research team developed a list of National Organic Program-approved insecticides that can be used to control SWD. Although insecticides are typically needed to maintain fruit quality on commercial farms, organic growers should integrate cultural, physical, behavioral and biological tactics into their SWD management programs as much as possible to help ensure effective control and prevent insecticide resistance development.
10 TIPS
Based on research findings, implementation of the following strategies is recommended to effectively control SWD and protect fruit.
Planting regionally appropriate early-ripening varieties and varieties with thicker-skinned fruit can help decrease the chances of SWD infestation.
SWD adults are very sensitive to desiccation (drying out) and do not perform well at high temperatures and low humidity. Heavy pruning of blueberries will allow more light to penetrate through the canopy, which may lower humidity and increase temperature leading to less SWD infestation.
SWD larvae often emerge from fruit to pupate in a suitable protected place, usually under the soil surface. Using black plastic weed mat as mulch on the ground provides an effective barrier that prevents larvae from pupating underneath the soil surface, reducing SWD survival in the field.
Physically excluding SWD from the crop is very effective in preventing SWD infestation. Timely installation of insect netting to high tunnel infrastructure (side walls and ends of tunnels) provides a physical barrier to SWD.
Over-ripe and damaged fruit act as a reservoir for SWD and other pests in the field. Do not leave waste piles of fruit in the open. They should be bagged, burned or frozen. If bagging the fruit, use a clear trash bag and leave it in the sun for at least 48 hours to kill the larvae.
SWD has a broad host range and will infest other non-crop plants, especially those that produce small fruits. A list of plants that can serve as SWD hosts is available at https://bit.ly/2JeVDwd. If these alternate plant hosts are present on the edge of the field, removing them could decrease the onset and severity of the SWD infestation.
Ripe berries serve as a strong attractant for SWD. Frequent harvesting of the ripe fruit will decrease risk of SWD infestation in the fruit.
Once SWD is detected in traps, insecticide applications need to be made to protect fruit from SWD infestation. Conventional management programs rely on the frequent use of pyrethroid, spinosyn, organophosphate, carbamate or diamide insecticides. Of these chemical classes, only the spinosyn insecticide spinosad is approved for use in organic systems. This means that other non-chemical control measures must be implemented to control SWD in organic berries. Among the organic insecticides, Entrust (spinosad) is the most effective but must be rotated with other insecticides to decrease resistance development and meet current label requirements. Products that can be used in a rotation program with Entrust include Pyganic, Grandevo, Venerate and Azera. Agricultural sanitizers such as Jet-Ag and OxiDate 2.0 used in tank-mix or rotation with insecticides also show some promise for use in organic integrated pest management programs.
Spray coverage and timing of applications are critical to achieving good control. Sprayers should be calibrated at least annually, and appropriate spray volumes used to achieve excellent coverage. Initial research suggests that SWD are more active in the field during cooler parts of the day, in the morning and at dusk. Targeting sprays during these times may increase efficacy. When bees are present in the crop, avoid insecticide applications. If control is needed, use insecticides less toxic to bees and do not spray when they are active.
After harvest, cool fruit as soon as possible to maintain quality. Cooling the fruit to 35°F for three days has been shown to kill SWD larvae. If fruit is sold directly to consumers, advise them to keep it in the refrigerator. Freezing the fruit will kill eggs and larvae of SWD.
SUMMARY POINTS
In a nutshell, controlling SWD requires a rigorous, persistent and diverse management plan. Using as many control techniques as possible will help to reduce SWD infestation. Continue to evaluate your management program by monitoring SWD populations. Sample ripe and ripening fruit regularly to determine whether your management program is working and respond in a timely manner if needed. Always stay informed of your regional SWD pressure and new management techniques by contacting your local research and Extension personnel and utilizing the resources recommended by them.
Figure 1. Roots of blue lupin (left) and sunn hemp (right) are infected with Meloidgyne arenaria root-knot nematode and stained with acid fuchsin. Nematode galls and egg masses are visible on blue lupin, indicating its susceptibility to the nematode. In contrast, sunn hemp-infected roots are gall-free with a few egg masses, suggesting that it is a poor host for M. arenaria.
By Abolfazl Hajihassani and Josiah Marquez
Multiple cover crops are excellent candidates for vegetable growing systems in the southern United States due to their ability to fix nitrogen, build and maintain soil organic matter, and suppress soilborne pathogens, nematodes and weeds. In addition, cover crops can be a valuable strategy for improving microbial diversity and soil health when properly implemented.
There is plenty of evidence in scientific literature to support positive effects of certain cover crops in management of plant-parasitic nematodes. The key to success is understanding the factors that drive variation. Though suppressive cover crops will not eliminate nematodes from soil, they may reduce their population densities enough to allow proper production of susceptible vegetable crops in infested fields.
In Georgia, multiple root-knot nematodes (Meloidogyne spp.) are widely dispersed in the southern part of the state where they cause severe yield losses particularly in cucurbits, eggplant, tomato and pepper. During a survey in 2018 for nematodes in commercial vegetable-growing regions in southern Georgia, root-knot nematodes were found in approximately 67 percent of fields.
In the Southeast, chemical control is the most predominant approach for managing Meloidogyne spp. in intensive cultivation systems of vegetables.
However, certain summer cover crops, including sunn hemp (Crotalaria juncea), sorghum-sudangrass (Sorghum bicolor x S. sudanense) and velvetbean (Mucuna pruriens) have been implicated in reducing population densities of root-knot nematodes in soil. In Georgia, despite long growing seasons, the practice of growing two to three crops on the same piece of land often leaves a narrow window for the use of cover crops.
COVER CROP CULTIVAR CONSIDERATIONS
Many summer cover crops are susceptible to nematodes, resulting in an undesired population increase in soil during the growth of crops. To avoid this, cover crop species or cultivars that are poor hosts (resistant) to nematodes should be recognized.
In an attempt to find alternatives for control of root-knot nematodes in vegetable production systems, a series of greenhouse experiments was conducted in 2019 at the University of Georgia Tifton campus. The goal was to identify cover crop species/cultivars with potential to prevent the reproduction of M. javanica, M. incognita and M. arenaria. The cover crop susceptibility/resistance was characterized by evaluating root galling and egg-mass index.
Results exhibited that different cover crops respond differently to infection by root-knot nematodes. For example, certain nematode-infected cover crops produce both galls and egg masses on roots, whereas others may only induce either galls or egg masses (Figure 1). M. javanica, M. incognita and M. arenaria aggressively reproduced on blue lupine (Lupinus perennis), hairy vetch (Vicia villosa) and cowpea (Vigna unguiculata). These plants were highly susceptible to these nematode species.
Cover crops that were highly resistant across all three Meloidogyne species include velvetbean, marigold (Tagetes sp.) and sesame (Sesamum indicum). Resistance to parasitic nematodes is characterized as the ability of a plant species to prevent root-knot nematode development or reproduction.
The reproduction of these nematode species on sorghum-sudangrass and sunn hemp varied from susceptible (good host) to highly resistant (nonhost) plants. For example, an unspecified cultivar of sunn hemp was susceptible to M. arenaria and resistant to both M. javanica and M. incognita.
KEY POINTS
In summary, proper selection of a cover crop plays a key role in control of root-knot nematodes. It is important to note that a cover crop species may not provide resistance to all species of root-knot nematodes. In addition, all cultivars of the same cover crop may not create equal levels of nematode control.
Figure 2. University of Georgia researchers are studying the effects of sunn hemp and tillage practices on soilborne diseases, nematodes and weeds. Sunn hemp is harvested and chopped followed by tilling the residue into the soil.
Special attention to the presence of other plant-parasitic nematodes in soil is also necessary when planting a cover crop. Past research has suggested that Meloidogyne-resistant cover crops may support the reproduction of other nematode types in the soil. If vegetable growers think they are having issues with nematodes, soil samples can be analyzed at nematode diagnostic services to determine the types/species of nematodes and their population density for proper selection and management of cover crops to meet goals.
Other key factors to get the optimal benefits of cover crops are planting time, seeding rates and termination (mowing) times. Currently, field research (Figure 2) is being conducted in southern Georgia to determine the effect of spring and summer planting of sunn hemp for optimal biomass production and its influence on nematodes, weeds and soilborne diseases. The goal is to examine the effects of cover crops alone or in combination with tillage practice or chemical control approaches for effective management of plant-parasitic nematodes.
Industrial hemp samples at the Everglades Research and Education Center. Photo taken 11-07-19.
Just past the midpoint of a pilot project to study if industrial hemp grows well in Florida, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers are already looking ahead to see what more they can learn.
The UF/IFAS Industrial Hemp Pilot Project team of scientists is engaged in a two-year research project started with hemp plantings in the spring of 2019. A report on the project’s findings will go to the Florida Legislature at the project’s completion but are heading out to growers in the state interested in industrial hemp.
“Our call to action is to help growers and investors make an informed choice whether to take a chance on hemp and how to grow it,” said Zachary Brym, assistant professor of agronomy at the UF/IFAS Tropical Research and Education Center (TREC) in Homestead and research lead for the pilot project. “The fact remains that Florida is an entirely new environment for industrial hemp.”
Among other research objectives, UF/IFAS scientists are working to identify varieties suitable for growing in Florida and develop management practices and cropping systems that are economically sustainable. They’re also identifying risk factors such as insects, disease and the invasive properties of hemp.
“The long-term goal of the project is to produce hemp crops in an environmentally conscious and socially responsible way while maximizing both plant health and yield,” said Brym.
PRELIMINARY FINDINGS
As the UF/IFAS Industrial Hemp Pilot Project team begins its second year of studies, researchers are warning growers of potential challenges that can affect the crop’s chances of success.
“Be cautious,” said Brym. “There remains a conspicuous lack of consistent science and support for genetics and management practices of hemp for Florida. Our work from 2019 looked at 45 or so varieties across the state. We cannot yet name any variety that did everything a farmer needs to grow a marketable product. We did see some hemp grow well in our trials, so we have something to work with.”
According to Brym, some varieties do not match the amount of daylength in the regions tested and flowered too soon. Some showed extremely high variability in growth and productivity. Many exceeded the 0.3 percent total delta-9 tetrahydrocannabinol (THC) limit at harvest.
“Each of these preliminary findings point to a risk for farmers,” said Brym. “I am also concerned about the risk to the environment.”
Reliable or consistent science-based information on fertilizer and irrigation needs for the plant do not yet exist.
“I worry that farmers will apply too much fertilizer or irrigation,” said Brym. “Our early work also begins to confirm the risk of hemp to escape from cultivation through errant seed banks and dispersal.”
Brym stressed the preliminary nature of these results and the opportunities to improve the outlook in the second year of the project. Given the need for more information and consistent results, scientists, like Brym, seek support for continued research.
“I hope that folks see the value in our preliminary findings. It’s important to report what we see from the science for better or worse,” Brym shared. “There’s a lot more work to be done.”
TRIALS AND EXPANSION
As part of the project, UF/IFAS established variety trials representing various uses (fiber, grain and CBD) from regions of origin throughout North America, Europe and Asia.
The trials were planted outdoors at three UF/IFAS research locations including the TREC in South Florida, the Agronomy Forage Research Unit in Hague and the North Florida Research and Education Center in Quincy. The first locations represented the broad range of environments, climates and farming regions of Florida. They provided the ability to assess the genetics, management practices, cropping systems and potential risks of growing in those regions, said Brym.
An invasion risk assessment at the Bivens Arm research site, located near UF’s main campus in Gainesville, has been assessing natural conditions and habitats where hemp might establish and spread outside of cultivation. The study looks at the risk of any hemp plants becoming invasive threats to Florida’s landscapes.
According to Brym, research has expanded with industrial hemp currently being grown at eight permitted UF/IFAS locations. Cultivation now includes greenhouse propagation as well as outdoor planting. Following the initial screening of varieties, additional trials were planted to improve seed emergence, pre-plant seed treatments, herbicide control and soil drainage.
What started with a core team of seven faculty members from three departments and the College of Pharmacy has expanded to 20 faculty members from a greater variety of disciplines.
Researchers from the expanded team looked into the basic physiology of hemp in a controlled environment and monitored for pests and diseases on hemp outdoor trials. Their involvement was critical when two propagation greenhouses went under quarantine for pests that appeared on transplants from outside of the state after initial delivery inspections.
“We can thank the continued industry support and investments that helped us meet our research milestones. Our research efforts to date have made great strides in making information available to this emerging industry,” said Brym. “We’re geared up to complete the pilot project in 2020 and look forward to continued engagement with the industry.”
Integrated techniques are needed for fusarium wilt management.
By Nicholas S. Dufault
It has been more than 120 years since an unknown watermelon wilt disease was observed to cause heavy losses in the southern United States. The re-emergence of this disease, identified as fusarium wilt (FW) caused by the fungus Fusarium oxysporum f. sp. niveum (Fon), has led to a need for alternative control practices.
MANAGEMENT STRATEGIES
Numerous FW disease management strategies have been developed such as fumigation, long-term (>7 years) crop rotation, delayed planting, grafting and host resistance. This article will briefly discuss the pros and cons of current management techniques and explain how improved diagnostics with a better understanding of risk is important for future management of FW.
The techniques listed above can all be effective at managing FW. However, inconsistent results related to fumigation as well as delayed planting in Florida have led to a need to further investigate when and how to implement these management options. Grafting and cultivar resistance both provide effective control of Fon, but cost or mixed pathogen populations can impact their usefulness, respectively.
For example, the deployment of a resistant cultivar, even if it is not specific to all the races in the field, can result in less wilting than cultivars without resistance. The effectiveness of this technique is increased when the predominant pathogen present is the same race as the resistance trait. Unfortunately, there are times when the Fon population present in the field is not affected by resistance, which leads to significant wilting and losses.
NEW TOOLS AND MORE KNOWLEDGE NEEDED
Thus, deployment of new resistance sources is needed in combination with more accurate pathogen diagnosis techniques. Integrating these techniques, as well as others, will likely provide more consistent results for disease management. Finding the optimum integrated technique will require more information about the pathogen and disease risk.
To improve risk assessment for FW, a bioassay is being assessed that can help detect the pathogen in the field after a long rotation. In addition, a climate/risk index tool is being developed to determine FW risk. These tools can provide further insights into the risk associated with FW but should only be considered as decision support aides and not prediction tools. The effectiveness of these tools will be improved by better documenting the Fon genotype present within a given field.
Research currently being conducted across the Southeast is focused on expanding the understanding of the pathogen’s genetics. This genetic information can also be used to improve the understanding of the FON races and maybe even provide insights into what makes the pathogen virulent. As further information is gained about the pathogen’s genetics, it can be combined with breeding programs to focus on these virulence traits and used to improve disease diagnostic methods in the field and on the seed.
Substantial progress has been made on understanding FW management. Unfortunately, no single method has proven to be completely effective or economically feasible for disease control. Improved knowledge about the pathogen’s genetics will be critical to implementing proper integrated management techniques as well as accurately assessing disease risk related to field history, climate and diagnostics.
The May issue of VSCNews Magazine targets the best pest management practices for growers.
Researchers from the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) are already looking ahead and making plans to see what more can be learned about growing hemp in Florida, as they reach the midpoint of their pilot project. Lourdes Rodriguez, a public relations specialist for UF/IFAS Communications, provides a progress update of the UF/IFAS Industrial Hemp Pilot Project and future plans.
In the Southeast, chemical control is the most predominant approach for managing root-knot nematodes in vegetable production systems. However, multiple cover crops are excellent candidates for managing nematodes. Abolfazl Hajihassani, an assistant professor and Extension specialist at the University of Georgia (UGA), and Josiah Marquez, a UGA plant pathology graduate student, address considerations of selecting the cover crop cultivar best suited to your production.
Since its first detection in 2008, spotted-wing drosophila (SWD) has emerged as a devastating pest of berry and cherry crops throughout the U.S. Ashfaq Sial, an associate professor in the Department of Entomology at UGA, gives 10 of his best tips to effectively control SWD while protecting your fruit.
In addition, Hugh Smith, a vegetable entomologist at the UF/IFAS Gulf Coast Research and Education Center in Wimauma, Florida, provides readers with strategies to effectively manage diamondback moth larvae. Diamondback moths, which feed on plants in the crucifer family, develop resistance to insecticides very easily.
Finally, in the From the Back Forty column, growers can find information on relief efforts in the agriculture industry in light of COVID-19. Organizations such as American Farm Bureau and Florida Department of Agriculture and Consumer Services are working diligently to bring some relief to US farmers.
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Phytophthora fruit rot has been a concern for watermelon growers not only in Georgia but also in other states that grow watermelon. No single measure has been shown to suppress the disease consistently and effectively, especially when environmental conditions are favorable for disease development.
Compared to other watermelon diseases, this disease is difficult to manage and strictly requires an integrated management program. Unlike on other cucurbit hosts (squash and cucumber, for example), phytophthora symptoms often appear on fruit and not on foliage. However, research indicates that all growth stages and plant parts are susceptible to infection.
In watermelon, fruit symptoms are quite common. Some of the common symptoms that can be observed on fruits are irregular to round, water-soaked lesions that become brown. As the disease progresses, concentric rings of pathogen sporulation may appear within a lesion.
Lesions can appear on the upper and/or lower surfaces (contact with the soil) of fruit. As the pathogen is soilborne, symptoms on the lower surface are quite common. Symptoms on the upper surface are presumed to be related to the dispersal/spread of the pathogen from contaminated soil. Under favorable conditions, complete rotting of fruit is common.
Phytophthora capsici can survive in soil or in host plant debris by means of thick-walled spores (oospores). Researchers have associated irrigation from contaminated pond water with P. capsici outbreaks in watermelon and other vegetable crops in Georgia.
The pathogen has two mating types (A1 and A2). Both mating types are necessary for oospore production. Presence of both mating types in vegetable fields is not uncommon in Georgia, which makes management more difficult. Spread of the pathogen is aided by zoospores, which are asexual spores that can swim in free moisture in the soil or on the plant surface and can infect the host. Zoospores are formed in specialized saclike structures called “sporangia” that can also spread by wind-blown rain and be carried through water.
Resistant watermelon varieties are not available. As a cultural control, it is recommended not to use retention pond water for irrigating watermelon crops. It is also advised to have good drainage in watermelon fields, which is sometimes difficult to achieve.
A preventive fungicide program is the key to get ahead with this disease. A fungicide program comprised of Presidio, Orondis Gold, Revus and Elumin may help.
Downy mildew has been a sporadic issue in watermelon as its incidence varies from year to year in Georgia. Unlike classical angular leaf spot symptoms that are observed in cucumber, symptoms on watermelon can be difficult to diagnose. Symptoms may start as irregular yellowish to brown spots that gradually become necrotic and often appear on upper surfaces of leaves. Lesions are often visible near the crown. As the disease progresses, necrotic lesions may appear on both sides of the leaf.
This disease can spread rapidly, aided by high humidity and wind-driven rain. Severe defoliation can be seen if timely management practices are not employed. Fruit rot due to sun scalding soon follows.
Resistant varieties are not commercially available. Crop rotation is impractical as the inoculum doesn’t survive locally in Georgia and arrives from Florida via wind current or any kind of weather events.
A preventative fungicide program is the key to get ahead with this disease. A fungicide program comprised of Ranman, Orondis Ultra, Revus and Elumin may help. Chlorothalonil (Bravo) can be used as a protectant until fruit set.
1) A bumblebee and sweat bee forage on the same flower, Cosmos sulphureus. 2)Sweat bees (Lasioglossum spp.) are so small they often go unnoticed. Sixteen species of these bees were collected visiting watermelon. 3) The Southern plains bumblebee (Bombus fraternus) is a frequent watermelon and wildflower pollinator on farms in South Carolina.
By Mimi Jenkins
A resilient and stable pollinator community includes a diverse suite of pollinators with a range of nesting habits, foraging behaviors and activity periods. These different behaviors and traits complement each other and can buffer against any year-to-year fluctuations or environmental changes that affect species differently.
BEYOND HONEY BEES
In many pollinator-dependent crop systems, honey bee colonies are brought onto the farm to provide the pollination services necessary to produce the crop. In the case of watermelon, a monoecious plant with separate male and female flowers that make it entirely dependent on pollinators to set fruit, using honey bee hives to pollinate the crop is widely recommended for growers to achieve high yields. While honey bees are an important agricultural pollinator, especially for industrial scale farms, considering alternative pollination sources that already exist in the natural environment helps buffer against ongoing honey bee losses and the rising cost of renting honey bee hives.
Wild native bee communities rely much more on the natural habitat of an area than honey bees because of their different nesting habits and because they are not actively managed by humans. Wild bees require habitat that provides food (flowers) and shelter (nesting materials and proper soil/environmental conditions). Other pollinating insects, such as flies and butterflies, share the need for floral resources with bees but many do not have a nest, and others require certain plant hosts or prey in their larval stage.
The flowering period of the wildflowers in this South Carolina strip began in May before watermelon bloom and lasted long after watermelon was done flowering, into August.
Implementing on-farm enhancements such as wildflower strips is one way to increase the availability and diversity of food resources for pollinators beyond the crop bloom period. Traits that should be considered for wildflowers in farm fields include: drought-tolerance, native to eco-region, fast germination rates, hardiness, difference in flowering period, length of flowering period and attractiveness to a variety of pollinating insects.
RESEARCH RESULTS
In a study I conducted from 2016 to 2018, the number of visits to watermelon was significantly higher for one group of pollinators (sweat bees in the genus Lasioglossum) when wildflowers were in a watermelon field compared to fields without wildflowers. These small, metallic grey-green bees nest underground and do not forage more than a few hundred meters from their nest.
In addition, the overall biodiversity of the pollinator community was higher in watermelon fields with wildflowers strips, with nearly twice the number of pollinator species collected on watermelon fields with wildflowers compared to control fields. The mean number of watermelon pollinating species per field was 15 species, and the mean number of total pollinators (including wildflower pollinators) per field was 24 species.
More than half (64 percent) of the watermelon pollinator species collected were also collected visiting one or more of five wildflower species in the study. This demonstrates that social colonies of bees, solitary bees and other insects like syrphid flies and butterflies utilize the multiple floral species as resources on the watermelon field in addition to the crop flowers when they are available. In fields with wildflowers, we also observed and collected a wide range of pollinators and insects that do not visit watermelon flowers but visited the wildflower species, such as several swallowtail butterfly species, cleptoparasitic bees and sunflower bees.
In conclusion, when wildflowers and weedy flowers are available on the farm landscape, a more diverse community of beneficial insects is supported. This community included declining species like Monarch butterflies, the American bumblebee and the Southern plains bumblebee as well as parasitic and predatory flies and wasps that can control crop pests.
At the 2019 Florida Ag Expo, visitors gathered at the Gulf Coast Research and Education Center (GCREC) for a trade show and field tour. Students and faculty from the University of Florida (UF) set up an Asian vegetable display that was visited by approximately 75 growers, educators, students and Extensions agents. Visitors conversed with students, read a flyer, took an identification quiz and watched a cooking video featuring Asian vegetables. They also had the opportunity to speak with UF associate professor Guodong Liu, who has dedicated much of his time toward exploring how to grow Asian vegetables.
Yanlin Wang, a UF graduate student, presented research on nutrition of Asian vegetables. She determined optimal fertilization of conventional luffa and long bean to be 150 and 200 pounds per acre of ammonium nitrate, respectively. Luffa was on display as well as nine other vegetables.
Luffa grows well in Florida because of the heat and moisture (Herklot, 1972; Purseglove, 1968). The two typically grown species are smooth (Luffa aegyptiaca) and ridged (Luffa acutangular). Mature fruit can be made into a fibrous sponge, and immature fruit are rich in minerals (phosphorus and potassium) and vitamins A and C (U.S. Department of Agriculture-Agricultural Research Service). The young leaves, flowers and buds can be eaten (Xie et al., 2016). Luffa has been used medicinally to treat diabetes and reduce risk of heart disease (Schilling et al., 1981).
Tong hao is an annual that grows highly branched foliage. It is slightly aromatic and has high quantities of beta carotene and antioxidants. It can be used culinarily, ornamentally or as green manure.
Nappa cabbage is a mild elongated Chinese cabbage also known as wong bok (meaning yellow white) because of its typical yellow heart. It is an incredibly healthy vegetable that is an excellent source of folic acid, vitamins (A and B) and calcium (Mendes de Lira et al., 2015).
Daikon radish is a mild Japanese radish with diuretic properties. Daikon radish forms a large taproot and dense foliage which may help reduce weed pressure. It decomposes quickly, releases nutrients and opens channels in the soil from decomposing roots, indicating cover crop potential (Gruver et al., 2016; Weil et al., 2009).
Yu choy is a cool-season leafy annual with slender, pale green stems. It is typically harvested after one month, but harvest time may vary. Yu choy has high concentrations of antioxidants and mineral nutrients (Kamarudin, 2012). The leaves, stems and flowers are all edible and taste peppery and sweet.
Shanghai bok choy has a light-green stem with smooth, spoon-shaped leaves. This crop can be grown in most parts of Florida year-round (Stephens, 1994). Harvest typically occurs after 30 to 45 days, and bitterness may develop if left in the soil too long (Tay and Toxopeus, 2016).
Bitter melon is a vine from south Asia that has spread through the tropics and subtropics (Hossain et al., 2006). It grows rapidly, so trellis-support is recommended. Immature fruit tastes pleasantly bitter and is an excellent source of vitamins (A, B and C) and minerals (calcium, phosphorus, potassium and iron). Chinese bitter melon tends to be smoother and less bitter than Indian bitter melon. Bitter melon also has medicinal benefits like lowering blood sugar (Zhang et al., 2018).
Kabocha is a winter squash that grows best in well-drained soil with organic matter (Liu et al., 2017; Purdue Extension, 2014). The yellow-orange flesh is sweet, starchy and firmer than common pumpkin. The seeds can be roasted and taste like pumpkin seeds.
Long squash is an herbaceous vine that needs trellis support. Long squash is a good source of vitamin C and potassium and has anti-inflammatory and cardioprotective effects. While not edible, the mature fruit can be used as containers, musical instruments or fishing floats.
Chinese eggplant is a perennial typically grown as an annual. It is long and has thin skin and few seeds. Chinese eggplant has been used medicinally for its antioxidant properties and for symptom reduction of toothaches, sores and intestinal disorders (Moore, 2007).
Asian vegetables grow well in Florida and have high market potential. John Sykes, a potato farmer with more than 1,000 acres of land, now grows Asian vegetables. He sees a market for them throughout the United States and in Canada.
