AgNet DEMO

Category: VSCNews magazine

  • Nematodes: Hidden Enemies of Asian Vegetable Growers in Florida

    By Mengyi Gu, Hung Xuan Bui and Johan Desaeger

    If you happen to travel around Wimauma, Florida, you will see many plastic tunnels and may wonder what they are. Asian farmers (mostly Vietnamese) are using those plastic tunnels to grow a wide variety of specialty Asian vegetable crops.

    Root-knot nematode galls on pumpkin roots

    There is a high demand for these vegetables from northern cities such as New York and Chicago, especially during the winter. In the United States, the demand for ethnic and specialty vegetables is rapidly increasing, and Asian vegetables have become one of the most popular specialty crops. The growing population of Asians, the blooming ethnic cuisine restaurants, and the demand from American consumers for Asian vegetables in their diet has boosted Asian vegetable production in Florida.

    The climate in Florida is very favorable year-round for growing many of the popular Asian vegetables. According to the 2019-20 Vegetable Production Handbook of Florida, currently more than 40 Asian vegetables are grown on 8,000 acres across Florida (with an increase of more than 3,400 acres over the past years). Some of the most common Asian vegetables grown in Florida include bok choy, long bean, bitter gourd, Thai basil, Malabar spinach, water spinach and mizuna.

    Recommendations for weed, insect and disease management in Asian vegetables have been published in the handbook. However, nematode management recommendations for these specialty vegetables are not available, and few growers are even aware of the existence of nematodes in their fields. Also, most of these ethnic farms are typically small (less than 50 acres), and many of them do not have pesticide licenses due to the language barrier. Because of this, these farmers tend to be isolated and have limited access to pest and disease management information.

    WHAT WAS FOUND

    During the past year, postdoctoral associates from the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Gulf Coast Research and Education Center (GCREC) nematology laboratory led an effort to visit some of the ethnic vegetable farms in Wimauma. The objective was to learn more about the crops that are grown and if nematodes are a problem. Most farmers were unaware of a nematode problem, but results indicated that five of the six surveyed farms did have visible nematode damage in the form of stunted and chlorotic plants. A total of 16 different vegetables were sampled, mostly leafy, but also some fruiting and root vegetables (Table 1).

    Table 1. Plant-parasitic nematodes found on different ethnic Asian vegetables grown in Florida

    Root-knot nematodes were the most commonly found and appeared to cause the most damage. Other potentially damaging nematodes that were found were sting, stubby root and lesion nematodes. While it is not known how much damage nematodes cause on these farms, Thai basil, pumpkin, Malabar spinach, Indian taro, sweet potato, jute, bitter gourd, luffa and Chinese eggplant showed visible aboveground symptoms, such as leaf yellowing and wilting.

    Plant-parasitic nematodes are microscopic roundworms that feed on living plant tissues. Most nematode species feed on the belowground parts of plants like roots and tubers, although some species feed on aboveground plant parts, which can sometimes be seen on strawberries in Florida. There are no typical aboveground symptoms of nematodes feeding on roots, and often their damage may be misidentified with other causes such as nutrient or water deficiency, or diseases related to bacteria or fungi (stunting, wilting and yellowing).

    It is estimated that global agriculture production loses more than $100 billion annually due to nematode damage. In Florida, year-round warm weather and high humidity create a perfect habitat for many plant-parasitic nematodes, and nematode damage can be very severe, especially in sandy soils.

    NON-CHEMICAL CONTROLS

    Since most Asian vegetable crops do not have a pesticide label, growers must rely mostly on non-chemical nematode management methods. Sanitation should always be the first recourse against nematodes.

    Growers should select sites with no or low nematode populations and avoid the introduction of nematodes into the field. It may be tedious, but it is important to clean farm equipment before and after working in different fields.

    A common way that nematodes are introduced into fields is through infected plant material (transplants or tubers). While it is generally difficult to recognize whether plant material is infected with nematodes, in the case of root-knot nematodes, the presence of galls or knots on roots of transplants or tubers is a telltale sign. However, nematode galls can easily be overlooked when they are small or when roots are covered with soil. For most other nematodes, no real diagnostic root symptoms can be observed on planting material, and proper diagnosis will need to be done at a nematology lab.

    Frequent applications of organic amendments (animal and green manures, compost, etc.) will increase soil organic matter and microbial activity while stimulating natural enemies that may reduce the damage caused by plant-parasitic nematodes.

    Crop rotation with nematode poor-host plants could be another option for Asian vegetable growers, but not enough is known now on nematode host status of Asian vegetables to make good recommendations. Planting cover crops in between vegetable crops is a widely adopted nematode-management strategy. For managing root-knot nematodes, sunn hemp and sorghum-sudangrass are recommended as cover crops since they are known to be poor hosts.

    The GCREC laboratory can help growers identify if they have nematode problems in their fields. Soil and root samples can be submitted to the laboratory free of charge. For more information, contact hungbui@ufl.edu (English or Vietnamese) or gumengyi@ufl.edu (English or Chinese).

    Mengyi Gu is a postdoctoral associate, Hung Xuan Bui is a postdoctoral research associate, and Johan Desaeger is an assistant professor — all at the UF/IFAS GCREC in Wimauma.

  • The Challenges of Controlling Silk Flies in Florida Sweet Corn

    Corn silk fly maggots injure sweet corn silks and kernels. Photo by Julien Beuzelin, UF/IFAS

    By Julien Beuzelin

    Corn silk flies are the most damaging insects of sweet corn in southern Florida. Adults of three species(Euxesta stigmatias, Euxesta eluta and Chaetopsis massyla) are commonly observed in commercial fields where they lay eggs on sweet corn silks. Maggots feed on silks and kernels before leaving the ear and falling onto the soil surface, under which they pupate. Adults emerge from the soil ready to mate and lay eggs within days, thus completing the pest’s life cycle.

    Corn silk fly maggot infestations and associated injury are responsible for crop losses every year, particularly in the spring. Losses occur because a small proportion of sweet corn loads might be rejected, but also because growers forgo harvest of portions of fields and sometimes entire fields when infestations are expected to lead to load rejections. These losses occur in spite of intensive pest management. In addition, corn silk flies have become increasingly challenging to manage over the past 20 years.

    Research conducted at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has focused on determining why corn silk flies are challenging to control and on developing improved management tactics.

    PYRETHROID RELIANCE AND SUSCEPTIBILITY

    Pyrethroids have become the cornerstone of corn silk fly management because effective alternatives in other insecticide classes have been phased out. Chlorpyrifos, methomyl and spinetoram also play a role currently. However, chlorpyrifos, which might lose its registration in the near future, can only be applied at a reduced rate within 21 days of harvest when sweet corn is susceptible to flies. In addition, methomyl has limited residual activity, and spinetoram is extremely expensive. Thus, chlorpyrifos and methomyl are frequently co-applied with pyrethroids to increase efficacy, and spinetoram is seldom used.

    Corn silk fly control is challenging because available insecticides are effective only if the insects are exposed to sprays or treated surfaces. Thus, only adults are the targets of management. Maggots and pupae are protected within ears and under the soil surface, respectively. Female adults escaping insecticide control or moving into sweet corn fields from adjacent habitats can lay eggs on susceptible ears, resulting in maggot infestations that cannot be further controlled.

    Repeated use of a single insecticide mode of action may lead to the development of insecticide resistance in pest populations. Therefore, pyrethroid resistance is a concern and may contribute to difficulties in controlling corn silk flies.

    Graduate student Eric Schwan Resende at the UF/IFAS Everglades Research and Education Center in Belle Glade has recently developedan adult vial assay for corn silk flies. This method involves coating the inner surface of small glass vials with a pyrethroid and introducing adults into the vials for 24 hours to record mortality as affected by different insecticide concentrations. It has been used to determine pyrethroid susceptibility for populations occurring in Florida sweet corn fields.

    Seven corn silk fly populations collected in sweet corn fields of the Everglades Agricultural Area and Homestead region in 2020 were evaluated using beta-cyfluthrin as a representative pyrethroid. The LC50, which is the estimated concentration killing 50 percent of the population, was determined for each population.

    In the laboratory, researchers are studying corn silk fly adults in vials to learn the effects of insecticide ingestion. Photo by Victoria Dunkley, UF/IFAS

    Two E. stigmatias populations from non-treated experimental fields had LC50s of 0.4 and 0.8 microgram (µg) per vial. Four E. stigmatias populations from commercial fields had LC50s between 1.5 and 3.5 µg per vial. One E. eluta population from a commercial field had an LC50 of 0.2 µg per vial. In addition, one E. eluta population maintained in the laboratory and serving as susceptible reference had an LC50 of 0.02 µg per vial.

    These results provide further evidence that E. eluta is more susceptible to pyrethroids than E. stigmatias. Thus, management should be more aggressive if E. stigmatias is present. Results suggest that E. stigmatias populations in non-treated fields are more susceptible to pyrethroids than populations in commercial fields that were intensively treated with insecticides. However, there is little variability in E. stigmatias pyrethroid susceptibility among populations in commercial fields. Thus, difficulties in controlling E. stigmatias are likely the result of high population levels, environmental conditions and the selection of less susceptible individuals in field populations.

    THE SEARCH FOR ALTERNATIVES

    Laboratory protocols were developed in 2020 to determine corn silk fly mortality associated with contact and ingestion exposure to insecticides including non-registered active ingredients. Preliminary experiments using E. eluta adults showed that whereas pyrethroids are effective via topical exposure, alternatives including neonicotinoids, diamides, abamectin and indoxacarb do not cause observable lethal effects. Via ingestion of insecticides at 1 percent of high field rates, the non-registered neonicotinoids thiamethoxam, clothianidin and dinotefuran caused 60 to 90 percent mortality.

    Although results need to be confirmed, these experiments show that potential alternatives to pyrethroids are not effective via topical exposure. However, some neonicotinoids are effective via ingestion. Thus, these insecticides cannot be direct replacements for pyrethroids, but they should be considered with baits forcing corn silk fly ingestion of insecticides.

    CONCLUSIONS

    High levels of pyrethroid resistance do not appear to be the main reason why corn silk flies are extremely challenging to control under current sweet corn production conditions. However, observations suggest reduced susceptibility in commercial field populations. Thus, adult vial assays are a newly developed method that will be used routinely to test field populations and monitor for pyrethroid resistance.

    With large corn silk fly populations building up, additional insecticides and new modes of insecticide delivery are needed. The use of baits and neonicotinoids have potential to control silk flies and will be further evaluated. In addition to insecticides, UF/IFAS entomologists will continue studying corn silk fly ecology, in particular the role of habitats adjacent to sweet corn fields to reduce or even prevent adult movement from adjacent crop and non-crop habitats.

    Acknowledgments: Corn silk fly research is partially supported by Florida Department of Agriculture and Consumer Services Specialty Crop Block Grants. Crop consultants and Dak Seal (UF/IFAS Tropical Research and Education Center, Homestead) assisted with insect collections.

    Julien Beuzelin is an assistant professor at the UF/IFAS Everglades Research and Education Center in Belle Glade.

  • Sneak Peek: March 2021 VSCNews Magazine

    The March issue of VSCNews Magazine targets the best pest management practices for growers.

    Asian vegetable production is blooming in Florida. As the industry flourishes, so are nematodes. Since most Asian vegetable crops do not have a pesticide label, researchers from the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) investigate non-chemical nematode management methods to control the pest.

    Mites can cause significant damage on blueberry plants if not properly managed. The southern red mite and false spider mite can wreak havoc on southern highbush blueberries throughout the Southeast. A team of UF/IFAS researchers address these pests and proper management tactics.

    Corn silk flies are the most damaging insects of sweet corn in southern Florida. Julien Beuzelin, an assistant professor at the UF/IFAS Everglades Research and Education Center, reports on his latest research.

    Lastly, pollinators play an important role in the production of crops around the nation. Florida’s hot, humid climate is ideal for crop production year-round. Unfortunately, this favorable environment paves the way for various pests. When using chemical controls, it’s important to consider the potential impacts on pollinators. Researchers at UF/IFAS address how to effectively manage pests while protecting pollinators.

    Find all these articles and more, coming soon in the next issue of VSCNews magazine.

    To receive future issues of the magazine, subscribe here.

  • Onion Disease Management in Georgia

    Bacterial streak and bulb rot caused by Pseudomonas viridiflava. A: Foliar symptoms include water-soaked lesions and collapsed leaf tissues. The corrugated appearance is due to protruding veins in leaves. B: A blue-green appearance is occasionally observed in post-harvest rots caused by this pathogen.

    By Bhabesh Dutta

    The climate prevalent in the Vidalia onion zone (southeastern Georgia) is conducive to many diseases. Among the diseases, those that are caused by bacteria and fungi are the prominent ones. Some of the diseases caused by water molds or oomycetes (Pythium damping-off and downy mildew) can also be seen periodically. Based on my experience as a vegetable Extension pathologist and onion disease specialist in Georgia, I generally see a seasonality to some of the important diseases. This article covers points that relate to disease seasonality and management.

    SEPTEMBER/OCTOBER PROBLEMS

    Onion seeds are sown around mid-September to early October on seedbeds. Some of the diseases that are normally seen during this period are Pythium damping-off and foliar blight caused by Xanthomonas leaf blight and Pantoea sp.

    Bulb rot symptoms of sour skin on onion. Photo credit: David B. Langston, University of Georgia, Bugwood.org

    Fungicides labeled for onion are effective against Pythium and can be used as a soil application according to the label. Use of optimum watering and avoiding seedbeds in low-lying areas of the field can also help in managing this disease.

    In terms of bacterial blights in seedlings on seedbeds, some growers use copper-based bactericides that are effective. Normally, nature takes its own course. When these seedlings are transplanted in the field, carry-over bacterial disease issues from seedbeds are seldom seen. This is in part due to the cooler conditions that are prevalent during December and January, which these bacterial pathogens do not prefer.

    Onion seedlings are transplanted after Thanksgiving or in late November and continue until mid-December. Diseases are not so common during these months; however, Vidalia onion growers use a preventive spray of broad-spectrum fungicides that provides a general level of protection against foliar fungal pathogens.

    Foliar symptoms of yellow bud disease on onion include intense chlorosis on emerging leaves and severe blight on the older leaves. Photo credit: Ronald D. Gitaitis, University of Georgia, Bugwood.org
    JANUARY/FEBRUARY DISEASES

    Fungal diseases are rare during December and January, but some bacterial diseases like bacterial streak and bulb rot (causal organism: Pseudomonas viridiflava) and yellow bud (causal organism: Pseudomonas coronafaciens) can be observed in late January to late February. Use of copper-based bactericide spray, optimum nitrogen fertilization and optimum irrigation generally help in managing these diseases.

    WHAT TO WATCH FOR IN MARCH

    As the temperature becomes moderate in March, along with frequent rainfall, Botrytis leaf blight (causal organism: Botrytis squamosa) and purple blotch (causal organism: Alternaria porri) can be observed. Stemphylium stem blight (causal organism: Stemphylium vesicarium) can also be seen in fields that are infected with either of these fungal pathogens. In general, Stemphylium sp. appears to be a weak pathogen under Georgia conditions, and it generally follows after Botrytis leaf blight, purple blotch or other diseases. A comprehensive fungicide program [as recommended by University of Georgia Cooperative (UGA) Extension] beginning in early March until harvest maturity (mid-April) effectively manages these three fungal diseases.

    During the same time, the dreadful downy mildew disease (causal organism: Peronospora destructor) can also occur. Downy mildew is sporadic but aggressive. This disease is favored by prolonged leaf moisture and cooler night temperatures.

    The fungicides that are labeled for use on onion against downy mildew are either moderately effective or less effective. Rotation of some of the moderately effective fungicides from different modes of action can help. Management practices that reduce prolonged leaf moisture and promote aeration can also help. The Vidalia Onion & Vegetable Research Center and UGA Extension specialists provide weekly forecasts of conditions that are conducive for downy mildew. These weekly alerts help onion growers to preventively spray against this pathogen.

    Symptoms of slippery skin include white and bleached leaves (A) and soft-rot symptoms in bulbs (B). Photo credit: Howard F. Schwartz, Colorado State University, Bugwood.org

    Bacterial diseases appear to be prevalent and problematic during the third week of March to harvest (late April) and can carry-over to storage (cause post-harvest losses). Some of the important bacterial diseases that Vidalia onion growers encounter are center rot (causal organism/organisms: Pantoea species complex), sour skin (causal organism: Burkholderia cepacia) and slippery skin (causal organism: Burkholderia gladioli pv. allicola). Sour skin and slippery skin are generally observed around harvest maturity.

    Some of the minor bacterial diseases that can also be seen around harvest maturity are Enterobacter bulb rot/decay (causal organism: Enterobacter sp.), Rahnella bulb rot (causal organism: Rahnella sp.) and Pectobacterium soft rot (causal organism: Pectobacterium sp.).

    Center rot outbreaks in Georgia generally coincide with the prevalence of thrips, which usually appear in late March and continue to increase in population throughout the rest of the crop growth period. Pantoea sp. can be acquired and effectively transmitted by thrips and hence, it is postulated that center rot appears in the Vidalia onion region when both thrips and Pantoea sp. are present together. Pantoea sp. can also be seed-borne, but its importance in disease outbreak may not be significant.

    The bacterium is also present on asymptomatic weeds as an epiphyte, and in most of the cases, the bacterium in non-pathogenic. However, some of the Pantoea sp. on weeds can be pathogenic on onion seedlings/plants. As far as management of this disease is concerned, an effective weed and thrips management program along with a bactericide spray (program during susceptible onion growth stages) can effectively reduce the incidence and severity of disease in foliage and bulbs.

    Onion bulbs reveal damage by infection with Enterobacter cloacae. Photo credit: Howard F. Schwartz, Colorado State University, Bugwood.org

    Sour skin and slippery skin management are quite challenging; in most cases, use of a bactericide program does not seem to effectively manage these diseases. Crop rotation may provide a limited benefit, but due to the pathogen’s natural widespread prevalence in soil, real benefits of this cultural practice are hard to achieve.

    Soil amendments with solarization, biofumigants and biocontrol also provided limited benefit, especially for sour skin. The UGA Extension Bulletin on bacterial disease management recommends avoiding overhead irrigation near harvest time. Another critical recommendation is harvesting onion at the optimum level of maturity followed by field curing for a minimum of 48 hours. Infected bulbs should be graded and discarded prior to storage with other healthy appearing onions. Evaluation of cultural practices, nitrogen fertilization, irrigation regimes (type, frequency) and post-harvest treatments are underway with support from the U.S. Department of Agriculture National Institute of Food and Agriculture Specialty Crop Research Initiative (2019-51181-30013) and the Vidalia Onion Committee grants. Production practices that generally reduce weeds, thrips and/or other insect pests, preventing injury to the foliage/bulb, avoiding over-irrigation, along with diligent use of a fungicide and bactericide spray program will help manage these diseases.

  • Choosing Cover Crops for Nematode Management

    Sunflower in the foreground and sunn hemp in the background

    By Johan Desaeger

    Cover crops are one of the more practical options for nematode management as their use is already common practice for many growers. The subtropical climate in Florida and the southeastern United States allows growers to plant crops year-round, and cover crops have been an important component of Florida’s agro-ecosystems since its early days of agriculture.

    Until the 1930s, velvetbean was a popular summer cover crop in Florida due to its nitrogen contribution. However, around the 1950s when chemical fertilizers and pesticides became widely available, cover crops became less common. Currently, the most planted summer cover crops in Florida are sorghum-sudangrass hybrids, sunn hemp (Crotalaria juncea) and cowpea (Vigna unguiculata). 

    SUMMER COVER CROPS

    Sorghum-sudangrass is a tall annual grass that is quite competitive against weeds. Leaf tissue of sorghum-sudangrass contains dhurrin, a cyanogenic glucoside that releases hydrogen cyanide upon degradation in the soil. While many varieties suppress root-knot nematodes (RKN) — by far the most damaging nematodes in Florida vegetables — sorghum-sudan is a good host to sting and stubby root nematodes. Sting nematodes are a major problem in Florida strawberries.


    Sunn hemp is a tall, rapid-growing legume that is widely grown in tropical regions as a green manure. In Florida, Tropic Sun sunn hemp produces high amounts of biomass. Its ability to fix nitrogen permits vigorous growth, even in sandy soils with low levels of nitrogen. Sunn hemp is well known to be a poor host to RKN and also to sting nematodes. However, it is a good host to lesion nematodes. Sunn hemp also contains alkaloids in its tissue, and both its leaf and root residue have nematicidal activity.


    Cowpea is a good fit as a summer cover crop for Florida growers. Unfortunately, cultivars like Iron Clay, which is the most common in Florida, is a good host to most species of RKN. Cowpea nematode susceptibility is greatly influenced by cultivar and composition of the nematode population. For example, while Iron Clay is a good host to most RKN species, California Blackeye No. 5, Tennessee Brown and Mississippi Silver are poor hosts to RKN. Both Iron Clay and Mississippi Silver can be good hosts for sting nematodes. In addition, cowpea is susceptible to southern blight, to which many Florida vegetables are also susceptible.

    WINTER COVER CROPS

    Common winter cover crop species include winter rye, oat, crimson clover, hairy vetch and several Brassica species such as mustard. These have varying effects on nematodes, but generally, when a susceptible crop is grown after them, nematode numbers quickly rebound.  Brassica plants like mustard and radish are also known to have biofumigant properties. This is due to the glucosinolates (sulfur-containing compounds) that they contain. Upon degradation, glucosinolates hydrolyze into several volatile compounds, including isothiocyanates (the active component of metam-based soil fumigants) and mustard oils.

    MIXING AND USE

    Cover crops can be sown as a monoculture or as a mix of multiple species. Mixing cover crops with opposing nematode host status can have benefits in terms of nematode management. Previous cover crop experiments by the author in Kenya, involving a mixture of good RKN hosts with poor hosts similar to sunn hemp, created a more diverse nematode population, reduced nematode damage and increased yield of an RKN-susceptible crop in rotation.

    The lack of nematode-specific data combined with the multitude of RKN (more than 15) and other nematode species in Florida warrants exploring the host status of cover crops (including cultivars) to each species of root-knot nematode. This is tedious work that takes time. However, such information would help growers to select appropriate cover crops, including mixtures that are tailored according to the resident nematode population of a field. 

    Properly managed, cover crops improve soil quality and health. They may impact soil nematodes in different ways, by limiting nematode reproduction during cover crop growth in the case of poor hosts, and by directly killing them via production of nematicidal compounds following incorporation of the biomass. In addition, by increasing soil organic matter, which is especially important in the poor sandy soils typical of Florida, cover crops can improve soil health by stimulating biological control organisms that are natural enemies of nematodes.

  • Tools to Solve Tomato Pathogen Problems

    Root samples of the rootstock Solanum sisymbriifolium (left) and Roadster tomato (right) are from a field infested with southern root-knot nematode M. incognita. Galls produced by the nematode are visible on the tomato root, while the rootstock root is free from nematode damage.

    By Abolfazl Hajihassani

    Tomato is the most economically important vegetable crop in the United States and has a history of heavy dependence on pesticides.

    PATHOGEN PAIR

    Root-knot nematodes and southern blight disease are among the most damaging pathogens of tomato. Pre-plant soil fumigation is often, but not always, effective at minimizing yield losses due to soilborne nematode and fungal pathogens. The fumigant 1,3-dichloropropene is only effective against nematodes and is not effective against soilborne fungal diseases. In contrast, the nematicidal efficacy of the fumigant chloropicrin is not the primary reason for its application against nematodes, as it mainly has fungicidal activity.

    Fumigants for control of these pathogens are diminishing due to environmental concerns and increasing regulations and restrictions on the use of these chemical treatments. Therefore, alternative control strategies have been extensively investigated over the past decade. Grafting tomato onto rootstocks with resistance to multiple root-knot nematode species combined with application of non-fumigant nematicides could offer effective management strategies that would provide growers with additional tools for managing root-knot nematodes. Moreover, using resistant rootstocks is one of the most effective methods to manage southern blight disease.

    Using a three-year award funded in 2019 by the U.S. Department of Agriculture National Institute of Food and Agriculture Methyl Bromide Transitions program, the University of Georgia (UGA) is investigating the effectiveness of a rootstock (Solanum sisymbriifolium) in managing root-knot nematodes and southern blight disease of tomato. Replicated field trials under experimental and commercial production conditions in Georgia are underway.

    Root-knot nematodes (Meloidogyne spp.) are tiny parasites that feed inside roots, induce galls (which contain nematode eggs) and disturb water and nutrient uptake from the soil into the plant, thus reducing crop yields. Root-knot nematodes cause approximately $15 million in damage annually to U.S. tomato production.

    In Georgia, five species of root-knot nematode are among the most important problems in tomato production. Tomato varieties with resistance to the most common species of root-knot nematodes (M. incognita, M. arenaria and M. javanica) have been released in the past, but these cultivars often lack resistance to other nematode species like M. enterolobii and M. haplanaria and to southern blight disease. Heirloom cultivars are particularly ­sensitive.

    Southern blight, caused by the fungus Athelia rolfsii, is a necrotrophic pathogen commonly found in many areas of the southeastern United States. Tomato plants infected with A. rolfsii wilt permanently in soil with a high level of pathogen inoculum, resulting in significant economic losses to growers.

    Roadster tomato grafted onto the rootstock Solanum sisymbriifolium (left) and non-grafted tomato (right) in the field are infested with southern blight. More than 80 percent of the non-grafted plants were dead by the end of the growing season.
    ROOTSTOCK TO THE RESCUE

    Grafting onto rootstocks resistant to southern blight can reduce the disease incidence and increase yield. Currently, the Maxifort rootstock, which carries resistance to southern blight, is commercially available. It also contains the Mi-1 gene that confers moderate resistance to species of M. incognita, M. arenaria and M. javanica.

    In UGA greenhouse studies, S. sisymbriifolium was challenged with M. incognita, M. arenaria, M. haplanaria and M. enterolobii. Results showed that it confers a high level of resistance to all four root-knot species. These results were also confirmed in microplot and field experiments using M. incognita species. The data suggest the importance of using S. sisymbriifolium as a resistant rootstock for effective management of these devastating nematodes in infested tomato fields.

    However, since grafted tomatoes are more expensive than non-grafted ones, growers will probably want to use rootstocks with resistance to multiple pathogens to minimize the production costs associated with application of multiple pesticides. Using a field study conducted in the summer of 2020, S. sisymbriifolium rootstock was found to be resistant to A. rolfsii. Field plots grown with tomato grafted on therootstock had significantly fewer dead plants compared to plots transplanted with non-grafted tomatoes.

    The next step in the research studies will be to evaluate the combined use of grafting and nematicides and/or fungicides to manage effectively both root-knot nematode and southern blight in tomato. Efforts will also include a cost-return analysis of the control practices developed in this project to compare with growers’ practices for disease management.

  • Cultivating a New Generation of Farmers

    An increasing number of today’s growers are first-generation farmers like Ida Vandamme. Photo by Sarasota Headshots

    By Sarah Bostick

    Every five years, the U.S. Department of Agriculture’s National Agricultural Statistics Service conducts a census. The 2017 Census of Agriculture captured in numbers what we see happening all around us: Farming is changing.

    GREENER GROWERS

    One of the most notable changes is that a growing number of farms in America are run by new and beginner producers — those who have operated a farm for fewer than 10 years.

    As of 2017, more than a quarter of all producers in America had farmed for 10 years or less. In 2017, there were 908,274 new and beginning farmers producing on over 193 million acres of land. In Georgia, Florida and Alabama, the percentage of beginning farmers is even higher than the national average: 33, 31 and 30 percent, respectively.

    This growing demographic of new farmers is also younger than the average farmer in America: 46.3 years old compared to 57.5 years old. Nationwide, 26 percent of beginning farmers are under the age of 35 compared to only 8 percent of all U.S. farmers.

    New farmers are much more likely to operate a small acreage farm. Beginning farmers are also significantly more likely than the average American farmer to work off-farm, earn the majority of household income from off-farm jobs, have a higher debt-to-asset ratio and have a higher expense-to-sales ratio. 

    Another reality is that beginning farmers are more likely to be first-generation farmers. For as long as humans have farmed, knowledge and land have been passed down from one generation of a family to another. That time-honored tradition is changing.

    The National Young Farmers Coalition (NYFC) is a non-profit organization with a mission of supporting young beginning farmers. In 2017, with the help of 94 partner organizations, NYFC surveyed 4,746 farmers across the nation. The survey (see www.youngfarmers.org/wp-content/uploads/2018/02/NYFC-Report-2017.pdf) showed that 75 percent of the respondents under the age of 40 did not grow up on a farm.

    So how is the next generation of farmers learning to farm?

    There are countless ways that organizations and individuals are creatively helping new farmers learn. Some of those ways are through incubator farms, farmer training programs, farm apprenticeships, conferences, farmer-to-farmer networks, and college and university student farms.

    INTERNING AND VOLUNTEERING

    In 2016, I was managing the University of Florida’s Field and Fork Farm and Garden program. The program provides an accessible place for students to get their hands dirty and learn to grow food. The program offered a dozen internships each semester, with many more applications than positions. A bright-eyed sophomore named Ida Vandamme applied that fall.

    I still remember Vandamme’s interview. She met us in the carrot field and we showed her how to weed. Without hesitating, she started the delicate work of hand weeding a 150-foot bed. While working together, we asked her formal interview questions. She didn’t skip a beat. She was clearly a natural at thinking, talking and doing at the same time — a skill that is essential in farming.

    Most students, including Vandamme, did not get an internship that year. We encouraged them all to volunteer that semester and apply next year. Vandamme took that advice to heart. She became one of the most consistent volunteers, happily harvesting cucumbers and stringing tomatoes while asking an endless stream of questions. She wanted to know how the things she was learning in plant science and sustainable food production classes related to what she was experiencing on the farm. Vandamme got the internship the next year and worked with Field and Fork until graduating in 2018.

    TRANSFER OF KNOWLEDGE

    One of the first farmers I met when I started my job as the sustainable agriculture Extension Agent in Sarasota County was Tiffany Bailey, a fifth-generation farmer and owner of both Bayside Sod Farm and Honeyside Farm, which produces vegetables. She grew up operating tractors, fixing machinery and understanding how to manage an agricultural business. In my first conversation with Bailey, she told me that she feels privileged that she grew up knowing how to farm and had a family farm to take over when her dad retired. She realized that most young people who want to farm start from scratch and she wanted to find a way to help change that for someone.

    Tiffany Bailey (left), owner of Honeyside Farm, makes it a priority to give her farm manager, Ida Vandamme, hands-on training. Photo by Sarasota Headshots

    A few months later, Bailey decided that it was time to train someone else to run Honeyside. She wanted Honeyside to grow and knew that she didn’t have enough time to do it herself. She decided to hire a farm manager. One of the people who applied for the job was Vandamme.

    When asked how qualified she was for the farm manager job that she has now held for a year and a half, Vandamme bursts into laughter and says, “Not at all!” Bailey knew that Vandamme wasn’t an experienced farmer. But she didn’t see this as a bad thing; she saw it as an opportunity.

    Bailey said she decided to take a chance on hiring Vandamme to manage her farm because “It is important to think about the responsibility that you have as an agriculture leader. You get to positively impact someone’s life. It doesn’t always work great. You have good days and bad days. But at the end of the day, the thanks you get from the people you have empowered to learn to grow food is amazing.”

    Hiring Vandamme forced Bailey to get all the details out of her head and create systems that other people could easily plug into. “If only you know how to do everything, you can’t grow and you can’t further your impact,” says Bailey. “You are going to stay where you are.”

    Bailey has some advice for established farmers who want to be part of training the next generation of farmers: The transfer of technical knowledge has to be hands-on. “Keep it teachable and keep it repeatable,” she advises. What doesn’t work is thinking that everyone is going to be good at doing everything from the get-go — that take times.

    Vandamme has some advice, too: Aspiring farmers can’t be scared to take the leap when an opportunity presents itself. For Vandamme, applying for a job managing a 10-acre vegetable farm was her big leap.

    “Coming to Honeyside is the best thing that has ever happened to me,” says Vandamme. “I think I won the lottery with Tiffany.”

    For Vandamme, a young first-generation farmer, the hardest thing to learn about managing a farm has been putting all the little pieces together into the big picture. Bailey is committed to helping her with this process.

    An increasing number of today’s growers are first-generation farmers like Ida Vandamme. Photo by Sarasota Headshots

    Vandamme dreams of owning her own farm someday. Land access is the No. 1 barrier to farming for young farmers, and Vandamme is no exception. Bailey hopes that Vandamme stays with Honeyside for a long time. But she knows that Vandamme will probably move on someday — either to start her own farm or work on a larger farm. Bailey hopes that by the time Vandamme moves on, she will leave with the skills she needs to succeed as the next generation of farmers.

    Farming in America is changing. Farming was once something that the younger generation learned from their parents, just as land was passed down through the generations. As more and more farm kids grow up and leave the farm, that generational knowledge is being lost. But it doesn’t have to be lost, and you can be a part of making sure that deep agricultural knowledge is passed on. I encourage new and established farmers to reach out to one another in the great American tradition of cultivating the next generation of farmers.

  • Imperfect Competition Yields Profitable Market Opportunities

    By Kimberly L. Morgan and Jessica Ryals

    Photo credit: © Foap.com / stock.adobe.com

    In nearly all introductory economics courses, the agricultural industry serves as the primary example of a “perfectly competitive” market structure. In theory, farmers are not able to set prices for their products, and instead “take the price” offered by market buyers. To achieve profitability, a grower works year-round to find ways to reduce costs, such as growing a single crop or renting more land, to take advantage of management expertise and investment in equipment.

    Let’s look at the other side of the profit equation to explore opportunities for Florida’s small- and medium-sized farmers to find ways to improve revenues. We can do this by identifying markets where they have some measure of influence on market prices.

    We describe markets in which firms may offer their products by setting their own prices as “imperfectly competitive.” Why are markets considered imperfect? What does this mean to farmers and buyers? What are the added costs and benefits related to stepping into imperfect markets?

    Successful ventures into imperfect markets are motivated by the farm manager’s decision to intentionally focus on solving the why lurking behind a customer’s buying decision. For example, why do we eat turkey on Thanksgiving, and maybe Christmas, but rarely during the rest of the year? Are there a lack of turkeys at other times of the year? Why can my class of college freshman rattle off the names of more than 10 apple varieties, but struggle to identify which nuts are picked off trees versus harvested from the ground? In this article, we highlight the power of marketing management to communicate and deliver added value to customers, which can result in higher farm revenues.

    DEFENSIBLY DIFFERENTIATE

    When farmers find ways to invest in marketing activities, intentionally carve out a targeted segment of buyers, and invest effort in building long-term relationships with customers, they become “defensibly differentiable.” The defensibility results from the ability of the farmer and the customer to nurture this relationship over time. The differentiation is built around the needs and wants unique to the target market and known only to involved parties. Higher profits are driven by tracking the marketing costs and setting prices to capture improved revenues that reflect the value of this shared information.

    To make money, farmers need to track customer data because it serves as the market feedback needed to make decisions to build their defensible market strategy. Prices tell the buyer what the farmer has invested in supplying the food and communicate why the food serves as the best choice to meet the buyer’s needs.

    The consumers’ actions up to and including the decision to buy the food informs the farmer about why that item is their preferred choice. Armed with this data, the farmer discovers the answers to the economic questions of what to produce, for whom, how much and when. This keeps customers returning to the farmer while also attracting others with similar demands. Empowered with market intelligence, farmers can make annual production and marketing decisions to protect their clients from competitors and cultivate their share of the target market.

    Why would a farmer be willing to invest in understanding individual food buyers’ wants and needs and setting their own prices? The food system works the way it does because it has proven to be efficient and effective over time. Keeping up with every person’s tastes and preferences is an impossible task for a single farmer. Identifying a market segment of buyers who are willing and able to spend their food dollars on a specific set of food products requires committed effort and the ability to react quickly in response to dynamic situations and unexpected events.

    As experienced farmers know, acquiring the necessary knowledge of market trends to communicate a “price story” requires time, effort, and perhaps, additional risk to the farm business. Added marketing costs and regulatory requirements beyond the farm gate, which include packing, storage, distribution, shipping, etc., must be factored into the pricing strategy.

    BUILD CONNECTIONS ONLINE
    The Southwest Florida Fresh website helps consumers find local producers.

    The key element that is driving opportunities for farmers to compete in imperfect markets is access to relatively cheap technology. Online platforms such as Facebook, YouTube and Instagram are useful to build connections that shrink the distance between farm and customers. Farmers can use these platforms to position their farm story and attract the attention of key influencers.

    Farmers can also share their relationships with their extended networks, which capitalizes on their investment in these promotional tools. Once a marketing campaign has begun, marketing managers can collect data generated by social media platforms, internet orders and mobile purchasing apps. This can capture real-time market reactions to messages aimed at communicating the value of product offerings.

    The Southwest Florida Fresh (swflfresh.com) website was created by the University of Florida Institute of Food and Agricultural Sciences in response to the devasting impacts of Hurricane Irma (2017), and more recently, the COVID-19 pandemic, on Florida’s southwestern farmers. The platform reduces distribution complexities and provides a regional brand for local producers, while meeting customer expectations for fresh local produce available at convenient venues. With consistent branding aimed at sharing each individual farm story, customers will continue to recognize and seek out your farm products across market outlets.

    SUMMARY

    Imperfect markets offer farmers improved profit margins, driven by the ability to set prices, based on knowing why people buy. Remember, that first customer costs a lot of money and time to attract, and data gathered along the way is valuable information. Long-term profitability for farmers who defensibly differentiate their food offerings is reliant on building loyalty and trust with customers, finding ways to encourage them to spend more at each visit, and incentivizing them to share their experiences with their friends and family networks.

  • Enterprise Planning Budgets for Growers

    © Wayne Smith

    By Kimberly L. Morgan and Tara Wade

    Wanna go fishin’? Have you ever wondered why we don’t ask who wants to go catching fish?

    Entrepreneurial adventures in farming may be compared to the distinction between fishing and catching any fish at all, regardless of hours spent throwing out a line, varying techniques, bait types, pole qualities and past experiences at previously abundant locales. Similarly, the farm financial planning process tends to be viewed as murky and mysterious. As a result, financial planning is often underutilized and misinterpreted. This is especially true when farmers are looking to make changes in existing operations or venturing into new enterprises.

    While financial documentation is viewed as a tedious task, it is the bedrock of any decision about farming.  Further, any future financial decisions should be made in tandem with production, marketing, legal, regulatory and human resource management to ensure all departments are considered prior to the investment.

    Business risks are defined as “uncertainty that matters.” This article highlights key aspects of the enterprise budget useful to address and mitigate the uncertainties that are inherent to entrepreneurial pursuit of farming for profits.

    Enterprise budgets are long-run planning tools. They differ from other budgets, such as income and cash flow statements, balance sheets and owners’ equity statements, which are used to study past farm financial performance. Enterprise budgets give farmers the numbers needed to make timely allocations of resources (land, labor and capital) specific to growing conditions that capture the feasible production and marketing costs and revenues.

    USEFUL FEATURES

    A key benefit to the enterprise budget is the ability to assess the opportunity costs, captured as interest paid on operating costs. Economic opportunity cost measures the entrepreneurial value of the enterprise by calculating what farmers must give up to get what they want the most.

    One alternative to borrowing annual operating capital and paying a 6 percent interest rate on the loan is to invest those dollars and earn a 6 percent return. The interest rate on the operating loan is charged to the enterprise in the budget to ensure the farmer is recovering this cost. Knowing what they are giving up allows farmers to make informed decisions on whether to choose a new enterprise.

    The University of Florida provides online tools to help growers with budgets.

    The enterprise budget contains another valuable risk mitigation tool: It allows farmers to examine whether they can stretch their resources into a new venture. Fixed costs, also described as ownership costs, represent long-term expenses that must be paid every year regardless of what commodity is produced or if any are produced at all. A fixed-cost charge in the form of returns to overhead and farm management is represented by a percentage of total operating costs. This percentage captures returns to the farmer’s own long-term investment of their expertise and efforts into this enterprise. Economics tells us there is no such thing as a free lunch, and this is the only financial tool that reminds the farmer to make sure any new activity results in a paycheck to cover their own involvement with the enterprise.

    A motivating factor for tackling a new enterprise is the desire to find new ways to use existing resources that are costing the business money yet sit idle all or part of a year, such as equipment, buildings or irrigation systems. The enterprise planning tool allows a farmer to adjust the variable (operating) and fixed (ownership) cost numbers to represent their existing resources and expenses. This can easily be done by utilizing information/numbers from the farm’s historical financial statements.

    Another valuable feature of the enterprise budget arises when farmers choose to spend time studying and learning how to utilize the tool to plan for future profits. Specifically, annual updates to the budgets capture information related to changes in input prices and/or technology.

    Examples of changes to input prices important to the farm budget are fuel or fertilizer costs resulting from adjustments in trade, labor or regulatory policies. Similarly, changes in technology such as new equipment features and/or availability can significantly impact overhead/fixed costs. Moreover, predicted yields may be changed to allow for varying physical conditions across the state, such as soil health and weather patterns that are specific to a farm location. Estimated costs of materials may be adjusted to capture savings from purchasing inputs in bulk for use across other farm activities or sharing packing and harvesting costs through cooperative arrangements.

    Estimated revenues are based on average market prices and can be altered to accurately identify prices received by an individual farmer year over year at each market outlet. This includes sales made through a broker, at a roadside stand or online farmers’ market, or via direct marketing connections like restaurants or retailers.

    From the viewpoint of an economist, assessing benefits resulting from the investment in a new enterprise extends beyond the explicit gains in profit. Farmers are often motivated by the implicit gains in managing business risks that may be achieved when adding a new enterprise.

    For example, the ability to employ labor year-round may ensure continued access to staff. This reduces the time and stressors related to attracting and training new people repeatedly, while building trusting relationships between owners and employees. This extends to finding ways for the next generation to stay on the farm through expansion into enterprises that provide the foundation for a long-term career in the family business.

    INTERNET RESOURCE

    To help organize the math behind these economic choices, the University of Florida Institute of Food and Agricultural Resources (UF/IFAS) provides enterprise budgets for a variety of Florida-grown commodities. These decision tools are built collaboratively with economists, horticulturists and farmers who share lifetimes of experience from the fields to provide a baseline of inputs and outputs for an operation.

    Visit fred.ifas.ufl.edu/extension/commodity-production-budgets for more information and to access the UF/IFAS Commodity Production Budgets. These tools will help you assess your farm’s readiness to capture your next entrepreneurial field of green. Available enterprise budgets include potatoes, strawberries, tomatoes, green peppers, watermelons, sweet corn, cabbage, tropical fruit, beef cattle and forages, tropical ornamentals, tropical vegetables, citrus and cucumbers.

  • Sneak Peek: February 2021 VSCNews Magazine

    By Ashley Robinson

    The February issue of VSCNews Magazine explores a variety of topics, including America’s changing farming landscape, onion disease management tips, nematode management strategies and tools for tomato production.

    Every five years, the U.S. Department of Agriculture’s National Agricultural Statistics Service conducts a census. The 2017 Census of Agriculture captured in numbers what we see happening all around us: farming is changing. Sarah Bostick, a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) sustainable agriculture Extension agent in Sarasota, Florida, shares how the industry is working to cultivate the next generation of farmers.

    Southeastern Georgia’s climate is conducive to many Vidalia onion diseases. Bhabesh Dutta, an associate professor and Extension vegetable disease specialist at the University of Georgia (UGA) in Tifton talks about disease seasonality and management strategies.

    Johan Desaeger, an assistant professor for UF/IFAS, is featured in the Organic Corner. According to Desaeger, cover crops are one of the more practical options for nematode management. He discusses various cover crops and their benefits.

    Additonally, Abolfazl Hajihassani, an assistant professor and Extension specialist at UGA, provides readers with tools to solve tomato pathogen issues.

    Finally, readers will get an inside look at the recent virtual Southeast Regional Fruit and Vegetable Conference from AgNet Media’s senior multimedia journalist Clint Thompson. The 25th annual event provided a unique educational experience, as the event was moved to an online format amid COVID-19 concerns. Thompson shares some brief summaries from a few of the educational sessions offered during this year’s event.

    If you would like to receive future issues of VSCNews magazine, click here.