The Steinernema scapterisci insect-parasitic nematode in the juvenile phase can infect and kill insects in the Orthoptera order, such as grasshoppers and crickets. Photo by David Cappaert, Bugwood.org.
Nematodes. Those microscopic, worm-like creatures that enter or attach themselves to crop roots, pierce root tissue, suck up root juices, and destroy crop yields.
Roots of a pepper plant infected by southern root-knot nematodes (Meloidogyne incognita) have extensive gall damage. Photo by Scott Bauer, USDA Agricultural Research Service, Bugwood.org.
But did you know, plant-parasitic nematodes are only a very small fraction of the nematodes living in your soil? And did you know most nematodes are harmless to crops – and many are even beneficial?
Although the threat of plant-parasitic nematodes damaging your crops is a concern, if a few important agricultural principles are followed – such as carefully designed crop rotations and building soil organic matter content – nematode-induced yield losses can be drastically reduced, while supporting nematode populations that will actually benefit your crops.
Nematodes are most abundant in the upper-most soil horizons, where up to 10 million individual nematodes can live per 10 square feet of soil. They subsist mostly in water-filled pore space near organic matter and plant roots.
Because of the havoc they can cause, plant parasitic nematodes, such as root-knot nematodes, have been the species most widely studied by scientists. But there are many other types of nematodes less studied, generally classified by their mouthparts and diet. Some strictly feed on either fungi or bacteria, while others are predatory, relying on other nematodes or protozoa for their diet; and others are omnivorous, able to feed on fungi and bacteria when their preferred prey is scarce, or conditions are unfavorable.
Light tillage, especially coupled with soil conservation practices and use of cover crops, can increase organic residue decomposition by bacteria and bacterial feeding nematodes, leading to more plant available nutrients for the season. Photo by Anthony LeBude, NC State University, Bugwood.org.
Different types of nematodes play different roles in a soil system. In row crop systems, maintaining a diversified food web through soil conservation and organic matter additions can support nematode populations that actually enhance nutrient mineralization and plant nutrient availability. This is especially beneficial in farming systems reliant on organic nutrient sources, as bacterial feeding nematodes consume nitrogen-containing bacteria and release excess nitrogen as plant available ammonium (NH4+). Nematodes can also rejuvenate old bacterial and fungal colonies and spread these microorganisms into organic residues whose nutrients may otherwise remain immobile and unavailable to plants.
Although overly intensive tillage can disturb the soil food web, properly managed tillage can actually promote healthy soil ecosystems. Light soil disturbances – especially coupled with compost and manure additions – increase the availability of organic residues to be consumed by bacteria, which in turn stimulate bacterial feeding nematodes, leading to a net increase of available nitrogen for plant uptake. And although fungal feeding nematodes are more abundant in no-till and perennial agricultural systems, bacterial feeding nematodes are better at releasing plant available nitrogen than their fungal feeding counterparts.
Thousands of Heterorhabditis bacteriophora insect-parasitic nematodes emerging out of a wax moth cadaver, ready for use as a biological control to protect crops from pests such as weevils, beetles, and flies. Photo by Peggy Greb, USDA Agricultural Research Service, Bugwood.org.
Another type of nematode that can be beneficial to farming systems is the insect-parasitic bacterial feeding nematode. These nematodes, such as the species Heterorhabditis bacteriophora and Steinernema scapterisci, have mutualistic relationships with bacteria, in that both the nematode and bacteria rely on one another to reproduce and grow. In their infective juvenile stage, these specialized nematodes carry within their intestines specific bacteria. The nematodes can penetrate the body of many insect hosts, such as cutworms, mole crickets, citrus weevils, sawfly and fungus gnat larvae, and many more depending on nematode species, and release the bacteria into the insect’s body cavity where it multiplies to the point of killing the insect. This allows the nematode to develop into an adult inside the insect’s body and reproduce new juveniles, which emerge from the cadaver to search for a new host. Thousands of nematodes can be produced from just one infected insect host. These types of nematodes are even available commercially as a biological insect control, most commonly applied to moistened fields as liquid suspensions at a rate of about one million per acre, depending on the crop. As they are living organisms, care must be taken not to kill the nematodes with excessive pressure, temperature, agitation, or sun exposure. It is also important to select the correct nematode species to match target insect pests.
A white grub larva infected by a Heterorhabditis bacteriophora insect-parasitic nematode next to two healthy white grub larvae for comparison. Photo by Whitney Cranshaw, Colorado State University, Bugwood.org.
Predatory nematodes have biological control capabilities as well, in that they can regulate populations of other nematodes – bacterial and fungal feeding – and most importantly, root-eating plant parasitic nematodes. And as part of any healthy soil food web, there are a wide variety of natural enemies that help keep in check nematode populations, such as predatory micro-arthropods and nematode ensnaring fungi. Agricultural systems designed to support a healthy soil ecosystem can therefore more successfully defend against plant parasitic nematodes and other crop diseases and pests. They can also facilitate enhanced nutrient cycling, which supports plant nutrient uptake, leading to overall healthy crop growth.
Tractor front loaders make turning large amounts of compost possible for farmers. Photo by Turkey Hill Farm.
International Compost Awareness Week is May 6-12 this year. This educational initiative, promoted by the Composting Council Research and Education Foundation, was started in Canada in 1995, and has continued to grow in popularity as communities, businesses, municipalities, schools, and organizations celebrate the benefits of compost and composting. But perhaps the most important people involved in composting are the farmers who produce compost to grow the food we eat.
Compost can be produced and used on the farm as a valuable soil amendment, capable of providing not only a source of slow-release nutrients for crops, but also a way to improve soil structure, increase soil moisture-holding capacity, promote biological activity to enhance plant nutrient availability, suppress weeds, and even help combat some plant diseases.
Farmers can source compostable materials from many businesses, including fish waste from seafood markets. Photo by Turkey Hill Farm.
Although creating on-farm compost can take a lot of time and energy, it can be worth a farmer’s effort, if it keeps soil fertility costs down. One way many farmers produce enough compost to meet their fertility needs is to collect waste products generated by their surrounding community. If a system for collection and transportation can be developed, and non-compostable waste can be excluded, farmers can use waste from grocery stores, restaurants, food processing facilities, breweries, seafood markets, horse stables, dairy operations, and chipped trees collected by power line crews as they clear encroaching tree canopies.
Once a farmer has secured sources for compostable materials, next comes the step of mixing the materials to generate heat, up to 140 degrees Fahrenheit. Fortunately for the farmer, microorganisms do most of the work in the decomposition process. But it is the farmer’s responsibility to provide enough – and the proper balance of – air, moisture, and nitrogen and carbon-rich food to fuel the aerobic microbial oxidation process. The volume needed to generate favorable composting conditions can be anywhere from about one cubic yard up to 40 cubic yards, depending on these factors.
This is why farmers, who depend on compost to supply a majority of their crops’ nutrient needs, often rely on a dump trailer and tractor front-end loader to move compost ingredients, turn compost piles, and spread the finished product on row beds. With experience, farmers learn the correct ratio of ingredients, proper volume and porosity of their piles, when temperatures plateau and piles need to be turned, and when the compost is finished and ready for use.
Spreading compost on crop rows provides a source of nutrients, improves soil structure, increases soil organic matter content, suppresses weeds, and provides many other benefits. Photo by Turkey Hill Farm.
High quality finished compost typically has an organic matter content of about 50 percent, a carbon to nitrogen ratio of around 20:1, near neutral pH, low soluble salts, and is free of weed seeds and plant phytotoxins. Compost nutrient content by volume is relatively low, and availability can vary greatly depending on soil and climatic conditions, so it is important for the farmer to monitor crop nutrient requirements and use additional amendments as needed. But when compost is used as a long-term strategy for improving soil health and building soil organic matter, its benefits can be appreciated for generations.
Interested in learning more about compost? Leon County Extension is hosting a “Got Compost?” workshop May 8, 6:00 p.m. to 8:00 p.m. EST, in celebration of International Compost Awareness Week. This workshop is tailored more for home-composters, but will also touch upon ways to up-scale compost production and will discuss small farm compost production strategies. To find out more and to register, visit the Leon County Extension Eventbrite Page.
Additionally, the Red Hills Small Farm Alliance – a non-profit organization of over 50 farmers within a 100-mile radius of Tallahassee – is promoting International Compost Awareness Week on its website and Facebook page. If you utilize compost on your farm, upload a short compost video to the Red Hills Small Farm Alliance Facebook Page for a chance to win a $50 gift certificate to the Red Hills Online Market.
Sally Waxgiser sells Sally’s Old Fashion Jams and Jellies in Jackson County utilizing the guidelines of the the Florida Cottage Food Law, which was approved by the legislature in 2011. Photo credit: Doug Mayo
Under the Cottage Food Law in the state of Florida, individuals can sell certain foods they produce in unlicensed home kitchens, if the food has a low risk of foodborne illness, as outlined in Section 500.80 of the Florida Statutes. These food products must be sold within Florida, they cannot be sold wholesale, and they must be properly packaged and labeled. Although products can be served as free samples for tasting, the samples must be prepackaged.
The label on Cottage food must include the name and address of the Cottage food operation, the name of the product, the ingredients in order by weight, the net weight or volume of the product, allergen information, nutritional information if a nutritional claim is made, and the following statement, “Made in a cottage food operation that is not subject to Florida’s food safety regulations.”
Recently, the Cottage Food Law was amended to include two important changes. These updates, which took effect July 1, 2017, increase the annual gross sales of cottage food products allowed under the law from $15,000 to $50,000, and make it possible for the producer to sell, offer for sale, and accept payment over the Internet, if the product is delivered in person directly to the consumer, or to a specific event venue.
As listed on the Florida Department of Agriculture and Consumer Services (FDACS) Cottage Food website, the following foods fall under the Cottage Food Law:
Loaf breads, rolls, biscuits
Cakes, pastries and cookies
Candies and confections
Jams, jellies and preserves
Fruit pies and dried fruits
Dry herbs, seasonings and mixtures
Cereals, trail mixes and granola
Coated or uncoated nuts
Vinegar and flavored vinegars
Popcorn and popcorn balls
For more information, please visit the FDACS Division of Food Safety website, and read their latest fact sheet called, Florida Cottage Food Guidance.
If you are a produce farmer, you should have heard about the Food Safety Modernization Act, or FSMA, by now. This act, which was passed in 2011, is considered the largest update to food safety regulation in over 80 years.
The proposed produce safety rule under the FSMA is very robust, establishing the minimum standards for worker training, health and hygiene, agricultural water use, animal soil amendments, on-farm domesticated and wild animals, equipment, tools, buildings, and sprout production. But just who does the new food safety rule affect?
First, the rule does not apply to produce that is not a raw agricultural commodity, or commodities the Food and Drug Administration (FDA) has identified as “rarely consumed raw.” Secondly, if your farm has an average value of produce sold of $25,000 or less within the previous three years, you are also exempt.
Fresh cucumbers, for example, are considered a raw commodity. But cucumbers that will undergo further processing, such as for pickling, would be eligible for exemption from the produce rule. Photo by Molly Jameson.
If you do produce an agricultural commodity in which the rule applies, and the value of your produce sold is over $25,000, it is still possible that your farm might be exempt from most of the requirements. For instance, if the average annual monetary value of food sold directly to qualified end-users was more than the average annual value of the food sold to all other buyers within the previous three-year period, you meet the first half of exemption eligibility. A “qualified end-user” is considered the consumer of the food, or restaurant or retail food establishment, located within the same state as the farm that produced the food (or no more than 275 miles).
If you meet the above exemption eligibility standards, you must also meet the second requirement. That is, the average annual monetary value of all food sold during the three-year period must be less than $500,000, when adjusted for inflation.
Not sure if you are exempt? View the chart developed by the FDA: Standards for Produce Safety – Coverage and Exemptions/Exclusions for Proposed 21 PART 112.
Whether you will be exempt from the FSMA produce safety rule or not, it is always a good idea to follow good agricultural practices and to have a farm food safety plan. To learn more about food safety on the farm, view the University of Florida IFAS document Food Safety on the Farm: An Overview of Good Agricultural Practices.
The UF/IFAS Small Farms Academy is offering a Building Your Own Farm’s Food Safety Manual Workshop in Tallahassee to help growers develop their own food safety manuals. This workshop is tailored to fresh fruit and vegetable farms, fields, or greenhouses, and is partially supported by a grant through the Florida Specialty Crops Block Grant program from the Florida Department of Agriculture and Consumer Services.
The registration fee is $35 for the first person representing a farm, and $15 for an additional attendee from that farm. The workshop is limited to 20 farms on a first come, first serve basis.
The workshop will take place at the Amtrak Station, County Community Room, 918 Railroad Ave, in Tallahassee, FL, on Tuesday, May 23, 8:00 a.m. to 4:00 p.m. Register on Eventbrite by following this link: https://farmfoodsafetymanualworkshop.eventbrite.com
Please note, this class will help you develop your farm’s food safety manual, but it does NOT fulfill the new FDA FSMA one-time training requirement.
Hosting a farm tour is an excellent way to connect with customers. Photo by Molly Jameson.
One excellent way to increase farm sales is to host a farm tour. In 2013 the Florida Legislature passed Senate Bill 1106, protecting farmers and ranchers from liability as long as activities are directly related to agriculture. This has opened up many opportunities for Florida farmers and has given citizens access to local farms where they can explore and meet the farmers where they work every day. Farm tours give the public the opportunity to not only see where their products originated, but also how they were produced and what farming techniques are actually used. This can help strengthen the relationships you have with customers, help you reach new customers, and make your farm stand out and be remembered.
Discuss all aspects or your farming practices, including cold protection, irrigation, and soil management. Photo by Molly Jameson.
One important aspect of planning a farm tour involves marketing. How will you let potential visitors know about your tour? If an organization, farm, or other entity organizes a farm tour event in your area, definitely take advantage of the opportunity. Often all you will need to do is complete an application providing a description of your farm and its amenities, and organizers will market the farm tour for you. If you live in an area without an established regional farm tour event, consider organizing one yourself or ask your local extension office for guidance and support. When advertising for your tour, include information on what visitors should bring, such as hats, sunscreen, water, and closed-toe shoes, as well as what not to bring, such as pets.
Once you have decided to host a farm tour, you then need to think about what you will discuss with your visitors. Remember that many people touring your farm may know very little about farming and will be interested in every aspect of your practices. Consider discussing your methods of fertilization, soil management, crop varieties, irrigation techniques, planting and harvesting schedule, equipment and tools used, and insect and disease management. Discuss with visitors what makes your farm unique, your experience as a farmer, where you sell your products, how you get your products to market, and your involvement within the community.
Allow visitors to tour as many areas of the farm as possible. Photo by Molly Jameson.
On the tour, include as many areas of your farm as possible, including fields, pastures, barns, packing sheds, greenhouses – and even beehives and compost piles. Set up a farm stand to give customers the chance to buy your products on site. If possible, include hands-on activities and demonstrations as part of your farm tour, such as sample tastings, weed and pest identification, or a harvesting demonstration.
Remember to use signs to direct visitors to parking, restrooms, where the farm tour starts, and other important information. You may want to consider offering light refreshments and water for your visitors. Also give your visitors clear safety instructions before entering an area, and post a sign about agritourism liabilities, as detailed in Florida Senate Bill 1106. You can purchase these signs from the Florida Agritourism Association website.
When concluding a farm tour, make visitors aware of your website and encourage them to follow you on social media. It is also beneficial to ask your participants for feedback about what they liked and didn’t like about the tour, so you can make improvements for future tours. Finally, take the time to reflect on the success, and think about what you could change to make your next farm tour event even better!
For additional information on this topic, utilize the following UF/IFAS Publication links: