AgNet DEMO

Category: VSCNews magazine

  • Capitalize on Conservation Funding and Enhance Produce Safety

    The Farm Innovation Project will deliver hands-on conservation and produce-safety training to growers.

    By Kristin Woods

    Conservation funding from the U.S. Department of Agriculture’s Natural Resources Conservation Service (USDA NRCS) can help growers implement good land stewardship practices in an economically sustainable way. While these practices may affect pathogen movement in the farm environment, they are not meant to reduce produce safety risk. Additional consideration must be given around how implementing specific practices could affect the safety of produce.

    MICROIRRIGATION

    The USDA NRCS Environmental Quality Incentives Program (EQIP) can provide cost-share reimbursement for the installation of microirrigation. This practice reduces overall water use compared to overhead irrigation by limiting water delivery directly to the roots of the plant and reducing evaporation. On some crops, microirrigation also reduces plant diseases caused by excess moisture accumulating on the leaves.

    From a food-safety perspective, microirrigation can reduce risk. For crops with the harvestable portion above ground, limiting water contact with that portion reduces the chance of pathogens from the water attaching to the surface of the produce. Additionally, the use of microirrigation can minimize the chances of water contacting produce by reduced splashing from the direct water to root application. If you are getting water from an open water source such as a pond, river or canal, the food-safety benefits are even greater since these water sources can be more likely to carry pathogens.

    When using surface water, a filter needs to be installed to prevent debris and solids from the water source from clogging irrigation lines. Because the use of water is reduced with microirrigation, this sometimes makes the use of novel methods for irrigation water treatment more feasible, such as UV light, which is more easily implemented with reduced flow volumes.

    ROTATIONAL GRAZING

    Growers operating diversified farms with both produce and animals can benefit from USDA NRCS EQIP and Conservation Stewardship Program (CSP) funds to help implement rotational grazing. While EQIP provides a one-time cost-share reimbursement, CSP provides ongoing payments based on the specific practices and the acreage that those practices are applied to.

    In the case of rotational grazing, EQIP might help with the upfront capital cost of cross fencing, while CSP helps a rancher enhance soil health and forage quality long-term. Animals can graze primary crop debris, graze cover crops and simultaneously apply organic soil amendments (manure) to a growing area. To maximize animal production and forage, carefully considering the number of animals and the available forage throughout the rotation is important.

    Because forage recovers faster when not overgrazed, land that is properly rotationally grazed can be more productive overall. For goats, rotational grazing also has the added benefit of helping reduce parasite loads, since the barber pole worm larvae, commonly affecting goats, resides primarily in the bottom three inches of grass.

    Implemented properly, rotational grazing can lead to more productive land.

    Whenever animals are present on a farm with fresh produce, there are additional food-safety concerns. Adherence to the National Organic Program 90/120 rule where manure is applied at least 120 days prior to harvesting crops where the edible portion of the crop has soil contact and 90 days prior to harvesting of other crops will reduce risk.

    Adjacent to animal production areas, you might also consider short vegetative buffers that will help reduce manure runoff into growing areas or water sources. Additionally, woody buffers may help with wind spread of pathogens and will provide habitat for pest predators and pollinators.

    CONSERVATION BUFFERS

    Conservation buffers are also supported by EQIP, CSP and several other USDA programs such as the Conservation Reserve Program, Wildlife Habitat Incentives Program and Wetlands Reserve Program. This broad support is due to the expansive benefits of conservation buffers to water quality, erosion preservation, and support for pollinators and insect predators.

    Conservation buffers are small strips of land strategically located to catch pollutants from entering water sources and to reduce erosion. According to NRCS, buffers can remove up to 50% of nutrients and pesticides from runoff, up to 60% of pathogens and up to 75% of sediment. Smart implementation also provides a diversity of habitat to support native plant, animal and microbial species, ultimately improving the environment for pollinators and pest predators. The ability of buffer strips to catch nutrient runoff and control erosion via wind spread and water runoff potentially reduces food-safety risk by reducing the physical movement of manure and general spread of pathogens in a farm environment.

    FARM INNOVATION PROJECT

    In December 2020, Alabama Extension, along with partners from the Deep South Food Alliance, Alabama A&M University, Fort Valley State University, Alcorn State University and the National Farmers Union, piloted a hands-on training program that will rollout across Mississippi, Alabama and Georgia this year. The program, geared toward small and limited resource growers, aims to improve farm viability by helping growers balance food safety and conservation concerns.

    Known as the Farm Innovation Project, the program will bring hands-on training on water conservation, water quality, soil health, rotational grazing and produce safety practices. It will also bring access to technology-based resources to farms and rural communities. Additionally, participants in the program will learn about USDA conservation funds available to help implement practices on their farms.

    To find out more about this project funded by the USDA National Institute of Food and Agriculture, go to aces.edu/farm_innovation.

    ACCESSING FUNDS

    The first step in accessing funds to implement conservation practices is to visit your local USDA Farm Service Agency (FSA) office to register and receive an FSA farm number. Once registered, visit your local NRCS office to learn about conservation programs in your area. Due to the pandemic, be sure to call ahead and make an appointment. More information on accessing NRCS programs can be found at nrcs.usda.gov.

    Kristin Woods is a regional Extension agent with the Alabama Cooperative Extension System.

  • Sneak Peek: May 2021 VSCNews Magazine

    By Ashley Robinson

    The future of weed control is here. The May issue of VSCNews Magazine provides the inside scoop on all things weed control.

    First up, Yiannis Ampatzidis, an assistant professor at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) at the Southwest Florida Research and Education Center (SWFREC) covers the future of precision weed control. Using artificial intelligence, Ampatzidis has shown that new spraying technologies are a significant improvement in efficiency and safety.

    Weeds are problematic throughout the entire year in Florida. Peter Dittmar, associate professor at UF in Gainesville, shares pre-emergent herbicides, post-emergent herbicides and nonchemical weed control for blueberries.

    In addition, Ramdas Kanissery, an assistant professor and Ruby Tiwari, a Ph.D. graduate student, both at the UF/IFAS SWFREC, discuss a pesky weed of vegetable production.

    Cutleaf evening primrose is an annual weed, or sometimes a biennial, commonly found throughout vegetable farms in Florida. The weed is a heavy seed setter and the seeds can remain viable in the soil for several decades. It creates a seed bank in the soil for future infestation if not managed properly. Together, Kanissery and Tiwari discuss management options.

    Switching gears, the 2021 Atlantic hurricane season is on the horizon, and now is the time to prepare. Pam Knox, agricultural climatologist at the University of Georgia, talks all things hurricane prep and recovery for fruit and vegetable growers.

    Lastly, in the Organic Corner column, Tiffany Bailey, owner, and Ida Vandamme, farm manager, at Honeyside Farms in Parrish, Florida, share their top secrets to successfully sell your products online.

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

    To receive future issues of the magazine, subscribe here.

  • Getting Bugs to Work for You: Biodiversity in Action

    Bees, flies and spiders are all attracted to floral resources and provide predation and pollination services in crop production.

    By Jason Schmidt, Carmen Blubaugh and William Snyder

    Before large monoculture agriculture became commonplace, farms had a bit of everything — from a vegetable garden and a fruit orchard, to a chicken coop and a honeybee hive, to a natural forest and even a lake or creek. These farms had rich and vibrant plant and animal life, healthy soils and good yields.

    In the last 80 years or so, farms have become larger, more uniform in crops, with higher inputs of water, fertilizer and pesticides — all to be able to get high-quality yields, feed a growing population and remain profitable. But another change is happening: our awareness that we need to restore some of that diverse farm life to sustain production.

    Biological diversity or biodiversity, the diversity of living things, has gained attention in the last decades due to the great value of many ecosystem services (i.e., natural ecosystem components that benefit humans) such as pollination and natural pest control. Building diverse, healthy and sustainable food production requires more than knowledge of pesticides, nutrients, irrigation and plant germplasm.

    Current messaging emphasizes “Protecting the life that sustains us” (the mission of the Xerces Society), and large global research teams are mobilized to evaluate the importance of biodiversity for crop production. A biodiversity-based economy places greater worth on biodiversity than just direct products. Conservation and restoration of landscapes is gathering interest as methods to provision biodiversity and associated ecosystem services.

    Could a field full of insects ever be a good thing? Maybe, if you are into “biodiversity-friendly” farming. For each pest, there are likely 1,000 species that are either beneficial or have an unknown role in agriculture. For the most part, having a field full of insects could be a good thing when there are many different types of insects. This is especially good if we see lots of bees, butterflies and predators, and a lot fewer pests damaging plants. Sadly, it is more common to hear about the bad bugs, especially when one species is having a tremendous impact on production.

    Generally though, more species provide more functions for a system. With diverse communities, there are many workers to do the necessary tasks (i.e., nutrient cycling, pollination, pest control, etc.) in the system. Having multiple species doing the same type of work can provide a back-up in case a player in the starting lineup goes down and a sub is needed. This is called resistance or ecological resistance.

    Planting wildflower strips along the edge of fields in marginal habitat not suitable for production can support diversity.

    Building diverse systems with many different species boosts resistance in the farming system because there is less risk to lose key functions like pollination and pest control. For example, growers are currently relying very heavily on one species of pollinator, the honey bee, to do a lot of work. Now that the honey bee is facing new parasites and other challenges, pollination is at risk.

    Another attribute of diverse systems is resilience. When things do go wrong or conditions change, diverse systems commonly bounce back quicker. Let’s looks at the steps growers can take to help restore and maintain biodiversity.

    STEP 1

    Plan for biodiversity during land conversion. Research has revealed that loss of diverse lands is likely one of the big drivers of biodiversity loss. We can tell this by using land cover maps to understand large patterns of habitat change. One clear pattern is that most (if not all) of the high-quality arable land is already in use, and in some areas, there is not much undeveloped land left to expand or we will be farming in wetlands, lakes, rivers or deserts.

    Habitat loss has become a strain on biodiversity because plant and animal species simply do not have places to live. Land-use analysis tells us that planning of any new land for conversion should also plan for providing permanent, non-cropping areas for buffering between waterways and other fields. These areas can be wetlands, stream edges, etc. The current rule of thumb, which requires a lot more study, is that 20% of land should be in non-cropping areas such as native forests and diverse wildflowers to buffer areas and provide food and shelter for biodiversity to prosper.

    STEP 2

    Grow fields with off-season cover crops to provide resources for aboveground and belowground diversity.During winter, when crop vegetation is dormant, habitat may be lacking in very large stretches of farmland. This means that valuable pollinators, parasitoids and predators have nowhere to dwell so they must rebuild their populations from scratch every year. Growing more green material builds a healthy insect and microbial community (which breaks down organic matter, brings nitrogen into the soil and improves soil structure). However, a soil left bare rapidly breaks down last season’s plant roots and releases carbon to the atmosphere instead of storing carbon and nitrogen for the next season. This results in a loss of valuable components of the nutrient cycle.

    Cover crops and mixed plantings can diversify production.

    The good news is that there are some simple, cost-effective ways to retain and build biodiversity aboveground and belowground. Cover crops (either single or mixed species) bring nitrogen and carbon into the soil and hold soil in place to reduce nutrient loss and erosion. They also provide habitat and food for species during times when the major crops are not growing in the field. Cover crops are an inexpensive solution to building soil organic matter, soil structure, and to feeding the invisible biodiversity of microbial (fungi, bacteria and algae) life.

    Researchers are just beginning to understand the complexity and dependency of the soil microbial community on cropping systems. Microbial life is incredibly diverse and very small. Biodiversity in soils can reduce vulnerability to extreme weather and to insect and pathogen attack by boosting plant defenses.

    Step 3

    SNAP to it! An acronym coined by Steve Wratten at Lincoln University in New Zealand is SNAP — provide shelter, nectar, alternative food and pollen. Habitat planning and restoring native habitat to agricultural landscapes can achieve SNAP conservation goals for the future of sustainable food and fiber production and help maintain valuable ecosystem services we depend on. Loss of habitat is a significant driver of biodiversity loss, so habitat management will help restore and sustain biodiversity in agricultural landscapes.

    So, what can we do? Practice integrated pest management and use pesticides only when there is evidence that they are needed (i.e., if scouting has shown the number of pests is over a harmful threshold). Practice crop rotation, diversify production with multiple crops, maintain permanent plantings of flowering plants in marginal areas of the field, and improve forest edges and buffers between agricultural land and waterways.

    Let’s SNAP our farms into rich, biodiverse lands to stimulate natural regulation of our food and fiber production ecosystems and to further agroecosystem tourism.

    Jason Schmidt is an associate professor, Carmen Blubaugh is an assistant professor, and William Snyder is a professor — all at the University of Georgia.

  • Shade Nets Show Benefits for Peppers

    Figure 1. Shade nets can prevent crops from receiving too much light.

    By Juan Carlos Díaz Pérez

    Vegetable growers know well about the importance of light to plants. Light is necessary for the process of photosynthesis through which plants convert light energy into chemical energy (sugars) needed for plant growth and development.

    LIGHT AND HEAT

    Light is electromagnetic radiation that comes from the sun. The portion of the electromagnetic spectrum that can be seen or perceived by humans, the “visible light,” is within 400 to 780 nanometers (nm). (A nanometer is a billionth of a meter.) Photosynthesis also occurs within this visible range.

    In addition to the visible light, infrared is an important region of the electromagnetic spectrum that is for plant growth. The infrared light covers the range from 780 nm to 1 millimeter. A little more than half of the electromagnetic energy received from the sun is in the form of infrared radiation. Objects such as plants, animals and the soil emit heat as infrared radiation.

    Heat is energy that flows because of differences in temperature. Although visible light and other electromagnetic radiations may produce heat, the majority of heat at the Earth’s surface is associated with infrared radiation. Thus, plant heat stress due to excessive light and temperature are related to high exposure to infrared radiation.

    Although not all scientists agree with the concept of global warming, most climate experts believe that Earth’s temperature has been increasing since the time of the Industrial Revolution. The rise in temperature affects agricultural crops and may increase incidences of pests and diseases. New pests and diseases have been detected in the last decades that have been linked, at least partially, to changes in climatic conditions.

    Vegetable crops are particularly sensitive to high temperature and high light intensity conditions. Vegetables typically require soil moisture availability to reach high fruit yield and quality. Under conditions of high light and high temperature, crops such as pepper plants show drought stress, reduced fruit yields and high incidences of fruit physiological disorders such as fruit sunburn and blossom-end rot.

    PROTECTIVE TOOL
    Figure 2. Bell pepper plants are grown under shade net supported with a metallic cable and posts forming a pyramidal structure at the University of Georgia in Tifton.

    Shade nets are a type of technology used extensively to protect vegetables and other horticultural crops from damage by high solar radiation, wind, birds and hail. Black nets are the most common and the least expensive (Figure 1).

    Shade nets help reduce the heat load on crops by absorbing a portion of the solar radiation (visible light and infrared) and may reflect or refract some of the radiation, depending on the color and chemical composition of the net. The percentage of the solar radiation reduced by the net (called the “shade factor”) may vary from as low as 15% to as high as 80%. The type of net shade factor to use depends on the crop.

    RESEARCH RESULTS

    A study at the University of Georgia (UGA) in Tifton was conducted to determine the response of bell pepper plants to nets with different shade factors. Bell pepper plants (cultivars Camelot, Lafayette, Sirius and Stiletto) were grown in the field following the recommendations of the UGA Extension Service. Plants were planted in the field during the spring season of two years.

    Table 1. Bell pepper fruit yield under field conditions in Tifton, Georgia, as influenced by shade factor of black nets. Values are the means of four cultivars (Camelot, Lafayette, Sirius and Stiletto).

    Plants were grown in unshaded conditions (0% shade factor) and under nets with 30, 47, 63 and 80% shade factors (Figure 2). Results showed that fruit marketable yield of the four cultivars was highest under nets with 30 and 47% shade factors (Table 1). The yield of nonmarketable fruit decreased with increasing shade factor, indicating that reduced light levels were associated with diminished incidences of fruit physiological disorders (sunburn). The fruit size also increased with higher shade levels. See doi.org/10.21273/HORTSCI.49.7.891 for a more detailed report of this study.

    In conclusion, shade nets with shade factors between 30 and 47% resulted in the following benefits:

    • Increased fruit marketable yield
    • Improved fruit size
    • Decreased incidences of fruit sunburn

    Juan Carlos Díaz-Pérez (jcdiaz@uga.edu) is a professor in the Department of Horticulture at the University of Georgia in Tifton.

  • Biological Control of Sweetpotato Whiteflies With Predatory Mites in Squash

    Adult sweetpotato whitefly Photos by L. Lopez

    By Lorena Lopez and Oscar E. Liburd

    The sweetpotato whitefly (Bemisia tabaci) is one of the most problematic pests in vegetable production in the world and it is a key pest in squash. Most significant damage caused by this pest is due to the transmission of viral diseases and its ability to rapidly develop resistance to pesticides.

    Sweetpotato whiteflies can develop from egg to adult in two to three weeks under optimal environmental conditions (77 to 91°F, 50-70% relative humidity). Adult whiteflies are ~0.03- inch-long, yellow insects with two pairs of iridescent white wings.

    Females can live up to 24 days and lay up to 300 eggs. Eggs are oval, pearly white to yellow, and darken as they mature.

    Whitefly nymphs disperse briefly within the same leaf and then attach permanently to the leaf while continuously feeding on its contents. Before turning into adults, nymphs are less flattened and have big red eyes.

    THE DAMAGE DONE

    Sweetpotato whiteflies are usually found living and feeding on the lower side of squash leaves. Nymphs excrete honeydew that accumulates on leaves, flowers and fruit when populations reach high numbers. This results in sooty mold (fungus) development, reduction in photosynthesis and fruit losses.

    A) Silvered squash leaves. B) Healthy fruit (top) and fruit with discoloration due to viral infection (bottom)

    Feeding of nymphs is also associated with the development of squash silverleaf disorder in pumpkins, winter and summer squash, and some types of butternut squash. Squash silverleaf causes the newly developing leaves to turn silver due to proteins in the nymph’s saliva. Decreased photosynthesis and yield reductions result from high silvering of the squash leaves.

    Additionally, sweetpotato whiteflies transmit multiple viral diseases to squash. These include cucurbit leaf crumple virus, cucurbit yellow stunting disorder virus and squash vein yellowing virus. Common symptoms of viral diseases in squash include plant stunting, leaf and fruit malformation, yellowing and discoloration.

    In Florida, squash is grown mostly during the fall from mid-September to mid-November. Some growers may also plant squash in the spring from mid-March to mid-April. It is common to have higher whitefly pressure during the fall compared to the spring season. The combination of whitefly-transmitted diseases with high pest infestations can cause up to 50% reduction in marketable yield during the fall compared with the spring season when fewer viral diseases and low whitefly infestation levels are observed. 

    WHAT TO DO

    The management of plant viruses is best achieved when resistant varieties are available. However, there are no squash varieties resistant to whitefly-transmitted viruses yet. Therefore, squash plant viruses are mainly managed by suppressing the vector.

    Sweetpotato whitefly populations are usually managed using insecticides that are applied on a weekly basis. However, the development of resistance against these insecticides is always a major concern. Entrust (spinosad) is a low-risk pesticide commonly used in vegetable crops, but it is not effective against whiteflies. Other low-risk pesticides such as M-Pede® (soap concentrate) or Azera® (azadirachtin + pyrethrins) are effective against whitefly populations and can be used together with biological control agents like predatory mites.

    A) Adult predatory mite (Amblyseius swirskii) females guarding eggs. B) Larvae (left) and nymph (right) of A. swirskii

    The predatory mite Amblyseius swirskii is an effective predator of major pests found in Florida squash including sweetpotato whitefly and thrips. A. swirskii feeds mostly on whitefly eggs and small whitefly nymphs. Data from University of Florida biological control field studies showed that the predatory mites released onto squash leaves can rapidly disperse to other plants and suppressed whitefly populations as early as four weeks after planting. Additionally, squash silvering can be significantly reduced when this predatory mite is released.

    Data from field trials also indicate A. swirskii can disperse regardless of the squash cultivar. Moreover, squash cultivars exhibit different levels of sweetpotato whitefly attraction and susceptibility to silvering. Gold Rush is a sturdy squash cultivar that showed fewer silvered leaves compared to high-yielding squash cultivars such as Zephyr and Cash Flow. Additionally, Zephyr and Cash Flow seemed more susceptible to squash silverleaf.

    Zephyr squash is very attractive to farmers and consumers due to its green-yellow tone, but it was observed to be highly attractive to whiteflies as well. This is probably due to the light green color of the leaves that make the plants easily detected by whiteflies.

    No significant reductions in yield were observed despite high levels of silvering. However, plants were observed to be stunted and deformed when infested with high numbers of whiteflies and in the presence of whitefly-transmitted viruses. Thus, early management of sweetpotato whiteflies is recommended to avoid risking fruit quality.

    It is important to combine the use of predatory mites with other practices such as intercropping flowering plants in row middles or at the edges of the squash crop to attract other predators and parasitoids that can complement the release of predatory mites. Additionally, low-risk pesticides can be used to lessen severe whitefly infestations three to five days before the release of the predatory mites. It is best to release the predatory mites early in the morning or late in the afternoon to avoid the hottest hours of the day, during days with low winds and when there is no forecast for rain.

    Lorena Lopezis a postdoctoral research associate and Oscar E. Liburdis a professor at the University of Florida in Gainesville.

  • Muscadine Grape: Key to Sustainable Florida Viticulture

    A fully mature cluster of black-skinned muscadine grapes

    By Manjul Dutt and Ali Sarkhosh

    Native to Florida and the southeastern United States, the muscadine grape (Vitis rotundifolia) is a lesser known relative of the European grape (descended from Vitis vinifera) that is popular worldwide for fruit consumption and wine production. A related species (Vitis munsoniana/Vitis rotundifolia var. munsoniana) is commonly present in the central and southern parts of Florida and is sometimes mistaken for muscadine grape.

    In Florida, wild muscadine grapes can be ubiquitous, with the vines growing happily among various oaks and other native trees. Sometimes, a few of them can reach several 100 feet in length, integrating well into the forest landscape.

    A young muscadine vineyard in Central Florida

    Wild muscadines were collected by settlers of the southeastern United States, and all commercial cultivated varieties have been developed from these collections. The first named muscadine variety, Scuppernong, was collected from a wild vine near the Scuppernong River in North Carolina.

    Muscadine grapes are low-maintenance crops that grow well in areas of high humidity and are tolerant to many insect and disease pests. Most commercially grown muscadines are highly resistant to Pierce’s disease. A minimal spray program with an occasional fungicide is required only in exceptionally wet years to control some fungal problems. Wasps can sometimes be a minor issue, building nests within the vines.

    IMPROVEMENT EFFORTS

    Muscadine improvement through selective breeding between good parents took place at the Agricultural Research Center in Leesburg, Florida. From 1959 onwards, several improved muscadine cultivar trials were initiated at Leesburg, and promising selections were subsequently propagated and evaluated at multiple locations (in North Carolina, Georgia and Mississippi) before release.

    Table 1. Muscadine varieties released by the University of Florida

    Since the late 1960s, muscadines have become commercially important in the South following the release of several Pierce’s disease-resistant cultivars with superior eating qualities from the breeding programs in Georgia, North Carolina and other southern states. The varieties released by the University of Florida (UF) are listed in Table 1. The groundwork for an active grapevine improvement program at UF was laid by the late John Mortensen, who joined the Leesburg Agricultural Research Center in 1960 and developed most of the UF-released varieties. Mortensen retired in 1991, and since then, there has been no active conventional breeding effort at UF.

    DESIRABLE TRAITS

    A prerequisite for commercial success in Florida is the resistance to Pierce’s disease. This bacterial disease results in grapevine mortality in susceptible cultivars. Pierce’s disease is spread by small insects called sharpshooters. Sharpshooters are widely present throughout the southern United States and are one of the primary reasons non-native grapes, such as the widely popular European wine grapes, cannot be grown successfully in Florida in the long term. Additionally, varieties must possess other fungal and bacterial disease tolerances to be successful in Florida’s heat and humidity.

    Some consumers who are not accustomed to muscadines do not like the typical muscadine aroma, which can be very different from that of vinifera grapes. Varieties with different aroma profiles could be successful. Varieties that have different flavor and aroma profiles will contribute to a growing niche market and popularize the grape to a wider audience. Furthermore, varieties that can mature over a longer duration from early summer to before the first frost are desirable to extend the harvest and marketing seasons.

    Varieties that produce fruits with a thin edible skin and crisp flesh are desirable and should preferably contain small/shriveled seeds or be seedless. Most commercial varieties are either black or bronze, but varieties with a wider range of colors are commercially desirable. An example of a muscadine that is neither bronze nor black is the newly released RubyCrisp cultivar from the University of Georgia. This cultivar, recommended for homeowners, is dark red in color.

    Muscadines are also highly perishable, which hampers their expansion to non-traditional marketing areas. Newer varieties with an enhanced shelf life can reduce perishability issues. Additionally, fruits should have a dry stem scar to prevent damage during picking and spoilage during storage and shipment.

    Muscadine grapes are notable for their high pigment and polyphenols content, especially those with a thick skin. Polyphenols are considered superfood components. In the human diet, these components can contribute to health and prevent disease.

    MARKETS AND VARIETIES

    As muscadines are tolerant to several common grape fungal and bacterial diseases, both commercial growers and homeowners can successfully grow muscadine grapes with a low input of pesticides. This is one of the main reasons for the popularity of muscadine as a sustainable fruit crop in the southeastern United States. The commercial acreage of muscadines in Florida is estimated to be 1,500 acres.

    In Florida, the most successful commercial plantings comprise large-fruited cultivars, such as Supreme for the fresh market, and high-yield cultivars, such as Carlos and Noble, for juice and wine production. U-pick operations are very common in fresh markets, and many growers market their products directly to consumers using roadside markets, farmers’ markets, local sales and other direct-to-consumer marketing strategies. Commercial muscadine vineyards that are based on juice or wine grapes generally offer on-site wine tasting.

    Manjul Dutt is a research assistant scientist at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center in Lake Alfred. Ali Sarkhosh is a UF/IFAS assistant professor in Gainesville.

  • Mite Management on Southern Highbush Blueberries

    Figure 1. Southern red mite adult female and male mating (top) and one egg (bottom). Photo by L. Buss, UF/IFAS

    By Oscar E. Liburd, Lorena Lopez and Doug Phillips

    Mites can cause significant damage on blueberry plants if not properly managed. Mite species that feed on southern highbush blueberries (SHB) include the southern red mite (Oligonychus ilicis) and the false spider mite or flat mite (Brevipalpus yothersi). The southern red mite is the primary mite pest feeding on blueberry plants in the southeastern United States and is common in fall and early spring. The false spider mite, first reported on SHB in 2016, is more common during summer months.

    SOUTHERN RED MITES

    In Florida, southern red mite populations increase under dry weather conditions with warm temperatures (60 to 86° F) and reach their peak during the fall. Their life cycle can be completed within two weeks under these conditions, and populations can double within five days with overlapping generations, increasing their potential for significant yield impact.

    Adults are similar in appearance to the red form of twospotted spider mites (Tetranychus urticae) and other red Tetranychus species, about 0.4 millimeter in length, red or brown to deep purple in color, with lighter colored legs (Figure 1). Females are slightly larger than males and have a more rounded body shape. Red to brown spherical eggs hatch into pale six-legged larvae. In the nymph stages, mites develop eight legs and are darker and larger.

    Figure 2. Female adult flat mite Photo by: R. Akyazi, University of Ordu
    FALSE SPIDER MITES

    False spider mites can complete their life cycle in about 19 to 20 days at around 77° F and 60 percent relative humidity. Adult flat mite females are flat and oval, approximately 0.3 millimeter in length, with red-orange coloring (Figure 2). Males and immature stages (larvae and nymphs) are similar in appearance and color pattern to the females but smaller. Eggs are bright red to orange and elliptical in shape.

    DAMAGE

    Southern red mites primarily live and feed on the lower side of SHB leaves. An accumulation of shed white skins can be observed when populations reach high numbers (Figure 3). Bronze coloring of leaves is the primary symptom accompanying southern red mite injury, with the intensity of bronzing increasing with the level of internal leaf damage (Figure 4). The southern red mite feeds on plant tissues by inserting its mouthparts into the leaf and removing cell contents, resulting in a decrease in the rate of photosynthesis.

    In SHB, leaves heavily infested with flat mites typically develop necrotic brown spots (Figure 5).

    Figure 3. Southern red mites shed their white skins on leaves. Photo by D. Phillips, UF/IFAS
    MONITORING

    In addition to differences in body shape and color, there are other distinctions between southern red mites and flat mites to consider when monitoring for these pests. Flat mites are smaller, move more slowly and are best observed with a hand lens or under a microscope. Southern red mites move more rapidly and can be observed with the naked eye on blueberry leaves. Southern red mites tend to feed over the entire surface of the underside of leaves and produce a web over the infested surface to protect them from predators. Flat mites typically feed near the midrib or secondary veins on the underside of leaves and do not produce a web.

    Mite populations tend to increase during hot, dry conditions. Frequent scouting for the presence of mites is recommended for early identification of infestations. Although southern red mites can be seen with the naked eye or a 10x hand lens, flat mites will need a higher magnification lens (20x) for identification.

    Typical symptoms of mite feeding (bronzed leaves for southern red mites and necrotic spots for flat mites) are also a good indication of mite infestations. However, monitoring for adults in addition to symptoms is important since by the time symptoms appear, infestation has already occurred and defoliation risk is increased.

    Closely examine the underside of leaves with the appropriate magnifying glass to look for adults, shed skins and webbing. Another way to scout for the presence of mites is to sharply tap the foliage onto a sheet of white paper to observe any adult mites.

    Figure 4. Bronze-colored blueberry leaves are associated with southern red mite damage. Photo by D. Phillips, UF/IFAS

    The pests favor dusty conditions, and drought-stressed plants can be more susceptible to infestations. In addition to supplying plants with sufficient irrigation, applications of water should be made regularly to roadways or other dusty areas during hot, dry periods.

    MANAGEMENT

    The flat mite is an important pest of citrus and its biology and ecological interactions have been studied in that cropping system, as well as most of the management techniques used for its control. Because it was only recently reported in blueberries, there are no established guidelines for the control of this mite in blueberry plantings. There is also no available information on miticide performance against flat mites infesting blueberries.

    The southern red mite is now an important pest in both protected and open-field SHB plantings. Three miticides — Magister (fenazaquin), Portal (fenpyroximate) and Kanemite (acequinocyl) — have recently been registered for use in highbush blueberries. These miticides target tetranychids and not specifically southern red mites, although Kanemite specifically mentions southern red mites on its label. The miticides control all developmental stages including larvae, nymphs and adults of southern red mites. In addition, Magister provides control of eggs by contact while controlling other stages by both contact and ingestion.

    Data from University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) 2020 field trials (where eight miticides were evaluated) indicate that Magister and Portal continue to be the best-performing miticides as shown in 2019 trials. Both products suppressed southern red mite populations and allowed bushes to recover from mite injury. Growers can only make one application per year using Magister and two applications per year with Portal. Kanemite was also effective at reducing southern red mites in 2020.

    Additionally, two sulfur-based products were evaluated in the 2020 field trials. Sulfur-CARB, a suspended sulfur soil amendment (elemental sulfur and molasses), is sometimes used for foliar applications to repel mites and insects. It provided good performance for control of mites only after a second application (14 days apart), as well as lower levels of bronzing at the end of the experiment. However, this product is not labeled specifically for southern red mites in SHB. Cosavet DF (sulfur) was not effective at reducing southern red mites.

    Figure 5. These necrotic brown spots on blueberry leaves are caused by flat mites. Photo by: R. Akyazi, University of Ordu

    Early identification of mite infestations and implementing management techniques before populations reach high numbers are recommended to avoid yield impacts. Although predatory mites have been an important tool that is used for controlling spider mites, to date they have not been successfully evaluated in blueberry systems.

    For more information, see UF/IFAS Electronic Data Information Source Publication ENY-1006, Mite Pests of Southern Highbush Blueberry in Florida (edis.ifas.ufl.edu/in1284).

    Oscar E. Liburdis a professor, Lorena Lopez is a post-doctoral research associate, and Doug Phillips is a blueberry Extension coordinator — all with UF/IFAS.

  • Sneak Peek: April 2021 VSCNews Magazine

    The April issue of VSCNews magazine explores biodiversity, conservation funding, watermelons and a variety of other topics.

    First up, an article by University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) professor Oscar Liburd and postdoctoral research associate Lorena Lopez, discusses how to control sweetpotato whiteflies with biological control agents like predatory mites in squash production.

    Conservation funding from the U.S. Department of Agriculture can help growers implement good land stewardship practices in an economically sustainable way. Kristin Woods, regional Extension agent in Alabama, shares how growers can capitalize on conservation funding and enhance produce safety.

    Manjul Dutt, a research assistant scientist, and Ali Sarkhosh, an assistant professor, both at UF/IFAS, collaborate about muscadine grape production. The authors discuss muscadine’s desirable traits, grapevine improvement efforts and more.

    Farmers realize the importance of biodiversity — the variety of plants, animals and microorganisms within an ecosystem, both above and below the soil to maximize the performance of their operation and to protect the environment. Researchers at the University of Georgia look at the steps growers can take to help restore and maintain biodiversity on their operation.

    The new Making Sense of Biologicals sponsored series of articles aims to educate growers on the diverse class of inputs known as agricultural biologicals. The April issue discusses how to enhance your crops with seaweed.

    The watermelon spotlight also returns to the April issue as growers are gearing up for harvest.

    Two growers, Carr Hussey and Bill Brim, shared their views on last year’s watermelon season and their expectations for this year.

    Also featured in the spotlight, AgNet Media’s Clint Thompson provides readers with the latest watermelon news, including whitefly management, improving flavor and National Watermelon Promotion Board appointments.

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

    To receive future issues of the magazine, subscribe here.

  • Effectively Managing Pests While Protecting Pollinators

    By Sylvia Willis, Amy Vu and Jamie Ellis

    Pollinators play an important role in the production of crops around the nation. Different crops rely on different techniques for pollination. Corn, for example, uses wind to carry pollen to female flowers, whereas watermelon depends on pollinators to deliver pollen. Pollinators include insects, birds and bats.

    Many fruits and vegetables result directly from pollinators such as honey bees. In apple, cranberry, melon, broccoli and almond production, honey bees are the most common pollinator. Honey bees are responsible for a significant portion of the world’s food production and contribute nearly $20 billion to the crop industry by providing pollination services all over the United States.

    In Florida, the hot, humid climate is ideal for crop production throughout the year, but this favorable environment also paves the way for various pests that negatively impact crops year-round. Growers use integrated pest management (IPM) to consider the risks and benefits associated with cultural, chemical, biological or physical control methods to combat pests. Typically, as a last resort, a chemical control is utilized to save a crop. When selecting a pesticide, growers should consider a chemical’s efficiency of pest control and potential impacts on pollinators when applied. 

    PESTICIDE EFFECTS
    Bee hives. UF/IFAS Photo by Tyler Jones.

    There are many factors that contribute to honey bee and pollinator stress, one being the use of insecticides. Effects of certain pesticides on bees can vary from no harm to acute harm (bee or single colony death) to chronic harm (altered bee behavior or physiology, reduced reproduction, colony decline or death). Suspected pesticide exposure is one of many biological and environmental factors associated with bee colony loss. Bees are likely exposed to pesticides outside the hive when foraging during the day. Plant foliage, pollen, nectar and soil can all contain potential toxins after direct application or drift from certain pesticides.

    Reading and properly interpreting pesticide labels and exposure warnings to honey bees and pollinators is vital. According to the Environmental Protection Agency, if a product is intended for foliar application to crops and contains a pesticide toxic to pollinators, the label must include appropriate cautions. Examples of bee and pollinator hazard warning statements are:

    • “This product is toxic to bees exposed to treatment and for more than five days following treatment.”
    • “Applications to all crops may be made at any time. Fenpyroximate is practically nontoxic to bees and wasps when used according to this label.”
    PROTECTION PRACTICES

    Protecting pollinators from pesticide exposure is on the forefront of many growers’ minds when considering pest control methods. For crops that require bees for pollination, it is in the best interest of the grower to protect bees. Without proper pollination, the grower’s crop production and yield are negatively impacted. There are a variety of best management practices that growers utilize every day to minimize impacts on honey bees and pollinators. These include:

    • Following the label – THE LABEL IS THE LAW
    • Obtaining a pesticide license to legally spray pesticides
    • Applying pesticides only when necessary
    • Employing IPM practices and using chemical control as a last resort
    • Spraying pesticides at night (label permitting) to maximize safety of honey bees and other pollinators
    • Utilizing target pesticide application such as injecting, rather than broad application
    • Selecting pesticides that require fewer applications, minimizing risk potential
    • Applying less toxic formulations and compounds
    • Developing a pest management plan that considers bee foraging during bloom
    • Understanding a crop’s pollination requirements to minimize exposure
    • Planting beneficial plants along field edges to provide additional resources for honey bees and other pollinators
    • Maintaining a good relationship with beekeepers and notifying them in advance of an application
    • Consulting with fellow producers, beekeepers and Extension professionals for recommendations
    EXTENSION’S ROLE

    Through services and educational efforts offered by Extension services, growers are provided appropriate tools to combat pest issues while also protecting pollinators, the environment and human health. Extension provides educational classes to enhance grower knowledge of pollinator protection on topics such as IPM (i.e. monitoring techniques, pest and plant knowledge, and pesticide selection) and best management practices regarding pest control.

    If pesticide application is necessary, Extension provides the training, testing and necessary certifications required to apply pesticides legally. In addition, Extension highlights up-to-date pollinator protection label changes during trainings and classes. Additional efforts of Extension agents and specialists include providing updates throughout the growing season to inform producers on potential pest issues, pesticide recommendations, and notifying producers of possible impacts on pollinators of certain products. 

    Understanding the importance of pollinators on the food system has brought increased awareness for pollinator protection programs and trainings. Growers can make a difference by making informed decisions to select and utilize chemicals with pollinator protection in mind. By building positive relationships between beekeepers and growers, an open dialog of communication can be established. As a result, growers can rely on Extension services when questions on chemical safety regarding honey bees and other pollinators arise.

    See Minimizing Honey Bee Exposure to Pesticides at edis.ifas.ufl.edu/pdffiles/IN/IN102700.pdf for more information on sustainable production practices and guidance on risk-reducing strategies to protect honey bee and pollinator populations.

    Sylvia Willis is the University of Florida (UF) Institute of Food and Agricultural Sciences Extension agriculture agent in Suwannee County. Amy Vu is an Extension coordinator and Jamie Ellis is the Gahan endowed professor, both at the UF Honey Bee Research and Extension Laboratory in Gainesville.

  • Regenerative Agriculture on the Rise

    By Sarah Bostick

    Regenerative agriculture is fast becoming a buzz phrase in America. You may have heard about it on the news, in feature films or in farmer forums online. You may have seen the words “regeneratively grown” on a box of mac and cheese, a tub of yogurt, a container of oatmeal or even a case of beer.  

    DEFINING THE TERM

    But what is regenerative agriculture? There is not one single working definition of regenerative agriculture, but at its core is the idea that virtually all agricultural farmland in the world has been damaged over time and that growers can actively improve the health of the land.

    Regenerative agriculture is best thought of as a collection of land management practices that restore soil health. The list of land management practices generally includes the use of diverse cover crops, managed grazing, the creation of on-farm fertility, no or minimal use of pesticides and synthetic fertilizers, and no or minimal tillage.

    INSIDE THE SOIL

    We often think of soil as simply soil, but soil is actually a very complex system. If you pick up a handful of healthy soil, approximately 45 percent of the volume is mineral (sand, clay or silt), 25 percent is water, 25 percent is air, and 5 percent is organic matter. Organic matter is a small part of most soil, but the services it provides to your farm are vast.

    Organic matter is anything that is or once was alive. Organic matter is the part of soil that most effectively captures and holds nutrients, prevents erosion and lessens the impacts of both flooding and drought. Organic matter is what makes soil the most biologically diverse ecosystem on the planet. It is also the part of soil that captures and holds carbon.

    It is this last bit — carbon capture and storage — that has caught the attention of people from every walk of life and recently put agriculture on the big screen.

    In the book “Soil as World Heritage,” soil scientists estimate that since the start of agriculture, approximately 320 billion tons of soil carbon have been lost worldwide from clearing land for agriculture. That is equal to the weight of 107 billion standard-sized pickup trucks.

    According to the book, most agricultural soils worldwide have lost 12 to 16 tons of carbon per acre. That’s equal to 25 to 75 percent of what existed before the land was first cleared.

    Where does soil carbon go when it is released? It goes back into the atmosphere in the form of carbon dioxide.

    Tillage releases carbon stored in the soil back into the atmosphere. By minimizing tillage and focusing on building organic matter, soil can store the huge quantities of carbon that plants pull out of the atmosphere through photosynthesis.

    The higher the organic matter level in the soil, the more carbon it is storing. According to Paul Hawken’s book “Drawdown,” for every 1 percent increase in soil organic matter, about 8.5 tons per acre of carbon are stored.

    Most of the attention that regenerative agriculture is receiving boils down to the idea that agriculture can be a powerful force in removing the top greenhouse gas (carbon dioxide) from the atmosphere.

    Farmers are clearly seeing the benefits. An estimated 108 million acres of farmland worldwide currently practice regenerative agriculture, according to “Drawdown.”

    If you are interested in learning about regenerative agriculture directly from farmers who practice it, here are a couple videos to get you started:

    REGENERATIVE ORGANIC CERTIFIED

    As of fall 2020, there is a new certification: Regenerative Organic Certified (ROC; regenorganic.org). The certification is overseen by a nonprofit organization called the Regenerative Organic Alliance. Rather than creating a different set of rules and regulations, ROC certification is based primarily on ensuring that a farm has a collection of other certifications.

    The three pillars of ROC are soil health, animal welfare and farmworker fairness. The soil health pillar requires that farmers be U.S. Department of Agriculture Certified Organic. The animal welfare and farmworker fairness pillars are proven through certifications such as Animal Welfare Approved and Food Justice Certified.

    CONCLUSION
    Regenerative agriculture doesn’t have a clear-cut definition, but it does have a growing following amongst both farmers and consumers. Regenerative agriculture is not an all-or-nothing concept. As you learn more about it, you might start with giving just one of the ideas a try. Regenerative agriculture is a process of learning what works on your unique piece of land.

    Sarah Bostick is a University of Florida Institute of Food and Agricultural Sciences sustainable agriculture Extension agent in Sarasota.