Solar Cropping System grant announcement

UVM EXTENSION EARNS GRANT TO STUDY SOLAR CORRIDORS ON FARMS Burlington–University of Vermont (UVM) Extension recently received a $68,438 grant from the U.S. Department of Agriculture’s Natural Resources Conservation Service to work with farmers interested in trying “solar corridors” in their corn silage fields. The project will be led by Dr. Heather Darby, a UVM Extension agronomist based in St. Albans and head of the UVM Extension Northwest Crops and Soils Team. Over the past decade, the team has worked with farmers to adopt cover cropping projects across the state. This new research project will further enhance the conservation benefits of cover crops on Vermont farms.

Solar corridor cropping systems use wide-row spacing of narrow, single or twin rows of corn to create a corridor between rows. This practice maximizes the amount of sunlight reaching the cover and corn crops, which can increase the yields of both. This type of cropping system also allows crops to grow throughout the year, which contributes to soil carbon storage, thus keeping carbon dioxide out of the atmosphere. In addition, better cover crop establishment aids water quality by increasing ground cover and holding soil in place to reduce nutrient runoff into lakes and streams.

Darby and her team will work with farmers to implement this new practice and develop practical and suitable recommendations for the Vermont landscape. Results will be shared at UVM’s No-till and Cover Crop Symposium, the Northeast Cover Crop Council annual meeting, Franklin Grand Isle Farmer’s Watershed Alliance meetings and on-farm field days, including UVM’s annual Northwest Crop and Soils Field Day.

More information about the research and outreach work of the Northwest Crops and Soils Team can be found at

Frost Seeding

Spring is right around the corner, but it might not be too late to think about forage improvements! Frost seeding is a simple practice that can help improve pasture and hay field yield, quality, and composition over time. The general principle of frost seeding is to broadcast forage seed onto pastures or hay fields in early spring when the ground freezes at night and thaws during the day. The time is now! Below are some helpful tips to make your frost seeding a success.

Expectations- Frost seeding will not look like a new seeding. New plants will grow over time and hard seed may sit around for a while until conditions are right. The first year you may not notice a huge difference but frost seeding a little bit each year around your farm can help maintain stands and avoid the need to do costly and extensive reseeding.

Limit competition– Frost seeding will be more successful where the seed can easily reach the soil surface. Fields that have a lot of bare ground showing or where you have grazed or mowed very short, will be more successful than fields with a lot of residue covering the ground.

Be ready to go when the conditions are right– At this time of year, fluctuations can happen quickly. Be ready. Walk your fields and decide which are the best candidates for frost seeding and what you’d like to seed (more on species selection below). When the snow is gone or mostly gone and the ground is freezing at night but thawing during the day, you should frost seed. Sandy soils that don’t heave and shrink under these conditions are generally poor candidates for frost seeding.

Species selection– To be ready when the weather is ready, you must select your species and purchase seed ahead of time. Frost seeding is more successful with legumes and grasses that can germinate quickly in cool temperatures. Red and white clovers are generally the most successful legumes while perennial ryegrass and orchardgrass are relatively successful grasses. Seeding rates of recommended species can be found in the table below.

Equipment– Frost seeding is often done with seeders mounted on ATVs, or a tractor mounted or hand held broadcast seeder. When frost seeding with a broadcast seeder, make sure to first determine the effective seeding width to avoid possible overlap of seed. Although not always necessary, a disk or cattle can help incorporate the seed into the soil. A no-till drill can be used but this will increase the number of trips across the field.

More information on frost seeding can be found at

Happy seeding!

Evaluating the Sensory Characteristics of Organic Grassfed Milk

By Roy Desrochers, Heather Darby, and Sara Ziegler

In the food and beverage industry, marketing and sales can get you first time buyers. However, product sensory quality — specifically aroma and flavor — are what drives repeat purchases and creates sustained market share. Simply put, food and beverage products that best meet consumer expectations for smell and taste sell better. Despite the rapid expansion of the grassfed milk industry in the last few years, little is known of the sensory characteristics and consumer preferences for grassfed milk. To address this, researchers from the University of Vermont, University of New Hampshire, and the USDA Agricultural Research Service (ARS) were awarded a USDA Organic Research and Extension Initiative grant to explore many aspects of grassfed dairy production in the U.S. One of the goals of the research is to gain a better understanding of the sensory quality of grassfed milk, and which factors at the farm level influence the presence and intensity of milk aroma and flavor characteristics preferred by consumers. And while we are still analyzing the results, at least one general finding stands out so far: There is a lot of variability in the aroma and flavor of grassfed milk products.

The research team is using a three-phase approach, each working at a different level within the grassfed milk value chain, to address these objectives: 1. Evaluate, characterize, and document the variability of grassfed milk aroma and flavor available to consumers in the U.S. market. 2. Evaluate and document the sensory characteristics of grassfed milk collected on-farm. 3. Define and quantify consumer overall liking for the aroma and flavor of grassfed milk samples representing a range of aroma and flavor quality.

What are sensory characteristics? Sensory characteristics are grouped into aroma and flavor. Aroma is what you smell when you sniff with your nose. Flavor includes everything you perceive when you put a product in your mouth, such as what you taste on your tongue, what you smell in your nose, and how it makes your mouth feel. Your tongue detects five basic tastes using its taste buds: sweet, sour, salty, bitter and savory (umami). Everything else that you think you taste in your mouth is actually flavor compounds that travel from your mouth to your nose through the back nasal passage. You can try this at home by simply holding your nose while you taste a food product. While holding your nose, you will be able to taste any of the five basic tastes present, but nothing else. When you let your nose go, you will taste (actually smell) the rest of the flavor. Mouthfeels are exactly what the term implies, which is how your mouth feels during and after consuming a product. For example, your mouth might feel dry when eating bread, or you may pucker when you drink a sour lemonade. In the case of milk, you will often experience a fatty or creamy coating inside your mouth.

Objective evaluation: Although laboratory analyses may be able to measure something like the pH or salinity of a sample, they cannot accurately measure the wide range of aroma and flavor a human can perceive. Therefore, the type of sensory evaluation in this project requires using humans as an objective analytical instrument. To evaluate samples objectively, tasters are trained using known reference standards to identify aromas and flavors on a standard, seven-point intensity scale: 1- No smell or taste, 2- Very slight smell or taste, 3- Slight smell or taste, 4- Slight-to-moderate smell or taste, 5- Moderate smell or taste, 6- Moderate-to-strong smell or taste, and 7- Strong smell or taste.

Trained tasters evaluate samples using the intensity scale to measure the following aroma and flavor attributes: Total intensity of aroma: The overall intensity of smell (aroma) of the sample. Balance: The harmony of the flavor. If individual flavors stick out and are easy to detect, the flavor is not balanced. Fullness: Fullness is a measure of the complexity of flavor. If the product tastes simple and thin, it is not very full. Total intensity of flavor: The overall intensity of taste of the sample. Five basic tastes: The intensity of sweet, salty, sour, bitter and savory taste on the tongue. Mouthfeel: The overall intensity of mouthfeel regardless of the type. This may be a mouth coating, dryness, salivation, etc. Others: The overall intensity of other notes detected that do not belong in one of the previous categories. Aftertaste at one and three minutes: The overall intensity of taste, regardless of what it is, left in your mouth at one and three minutes after your last sip. Others at one and three minutes: The intensity of other tastes in the sample at one and three minutes after the last sip. Mouthfeel at one and three minutes: The overall intensity of mouthfeel at one and three minutes after your last sip.

A panel of trained tasters used this approach to evaluate organic grassfed milk products purchased at supermarkets and grocery stores. In total, the trained tasters evaluated 35 milk samples representing the spring and fall seasons, three major milk companies, and three regions of the U.S. Although we are still analyzing results, so far we have learned: • Grassfed milk aroma and flavor vary between regions. • Grassfed milk aroma and flavor vary between seasons. • There is variability in grassfed milk aroma and flavor between milk companies. • There is variability in grassfed milk aroma and flavor within each milk company.

Again, these aroma and flavor differences were found in retail milk that had been both pasteurized and homogenized. This indicates there might well be major differences found in the bulk tanks of different farms. Recently, our project team began evaluating the aroma and flavor of grassfed milk samples collected directly from farms. So far, sensory analysis has been conducted on 31 milk samples from 29 farms in Vermont and New York. A second round of milk samples will be collected in the winter of 2021 to assess seasonal differences in milk aroma and flavor.

Although the study is yet to be completed, thus far we’ve seen that the range of sensory qualities collected on grassfed farms is similar to the supermarket samples. These findings are encouraging, as they indicate a possible opportunity for improvement by linking on-farm factors to grassfed milk sensory quality. For instance, it is very possible that specific grassfed feeding strategies can be developed with the idea of improving and maintaining the reliability of aroma and flavor qualities. We hope to initiate the consumer testing aspect of the project in late 2021. This testing will establish a specific sensory quality index that we can assign to all on-farm milk samples. We will then be able to correlate these against the farm factor data we are collecting to determine which factors and practices aid milk sensory quality.

We will continue to share results as they become available. Please feel free to reach out if you have any questions or feedback: contact Heather Darby at or 802-524-6501. This work is supported by OREI Project no. 2018-02802 from the USDA National Institute of Food and Agriculture.

Roy Desrochers heads up the sensory panel at UVM Extension and has over 37 years of experience working with food and beverage companies around the globe on issues relating to aroma and flavor.

Dr. Heather Darby is an Agronomist and Nutrient Management Specialist at UVM Extension where she leads agronomic research, outreach, and education programs on a wide variety of crops and cropping systems.

Sara Ziegler is a research specialist at UVM Extension focused on forage production and grass-based dairy systems.

Pasture, Rangeland, and Forage Insurance

Here is information shared by the RMA program and a link to a USDA news release about a public comment period on Pasture, Rangeland and Forage Insurance. The comment period is open until November 5, 2020. Comments can be submitted via email to or by mail to Director, Product Administration and Standards Division, Risk Management Agency, United States Department of Agriculture, P.O. Box 419205, Kansas City, MO 64133-6205.

Questions? Please contact Jake Jacobs, email: or message phone line: 802-656-7356 Website:

Be on the Look Out!

Hemp Diseases Creeping into Fields Across Vermont

Following are pictures of Septoria.

As the weather cools, rains, dews and fogs are becoming more common and diseases are on the rise. In the past couple of weeks, the UVM Hemp team has been scouting fields in the state and noted Alternaria and Septoria foliar leafspot diseases and Powdery mildew on plants. The foliar leafspots start low in the plant as small discreet circular spots (often with advancing yellow margins) that can coalesce over time and result in defoliation. The spores from these pathogens are rain splashed or blown throughout the foliage with each rain or wetting period. As air circulation becomes poorer in bushy mature plants, leaves are slow to dry off, increasing infection. Plastic mulches can help retain soil moisture and prevent spore splash up to the lower leaves early in the season. In one field, a Vermont grower used mulch both in the rows AND the alley ways, and no foliar leafspots were noted during scouting last week. This extra protection may have reduced humidity and helped minimize the incidence of leafspots. Although leafspots rarely kill a plant, they increase plant stress, reduce vigor and can negatively impact yield depending on their severity.

Powdery mildew is another foliar fungal disease that is becoming common in some fields now. This pathogen’s spores results in the characteristic white powdery coating on the foliage. This disease can be managed with applications of potassium bicarbonates and the horticultural oils. Again, repeat applications are necessary to keep foliage and buds protected. Below are pictures of Powdery mildew.

Fungicides may be necessary at this point in the season to protect the foliage and flower buds from further infection. Fungicides would also help protect buds from botrytis blights as the season progresses. Fungicide options in Vermont are limited to Bacillus spp. (Double Nickel, Serenade); Streptomyces spp. (Mycostop, Actinovate); several mineral or plant oils; hydrogen dioxides and peroxides, Regalia™, potassium bicarbonates, etc.

See link for the full list of what is allowable in the state:

These materials are applied as ‘protectants’ and would need to be reapplied on a regular basis until harvest. As with any pesticide, read the product label carefully and follow the instructions listed on the label.

Are you in need of additional feed? It’s time to think about cool season annuals.

Hot, dry conditions this season have made for some nice hay making weather, but poor hay and pasture yields. Many farmers are already looking at having to feed some of the stored forages they’d typically feed this winter to get by. Furthermore, as much of our region is experiencing this droughty weather, finding quality stored feed this fall or winter will likely be challenging and costly.

Planting cool season annuals such as annual ryegrass, oats, pea, winter grains, and brassicas, can help extend the grazing season, give perennial pastures a rest, and help ensure your stored feed stocks are adequate. Cool season annuals can be both harvested for storage and grazed in the late fall. The sooner you plant cool season annuals, the more time they will have to establish and produce biomass. In Vermont, this typically means planting these around mid-August.

Annual Ryegrass

Annual ryegrass is a fantastic fall forage. It establishes quickly and is very palatable for grazing. Annual ryegrass can produce about 0.5 ton of dry matter per acre in our region if sown by late August. The seed is typically quite inexpensive compared to winter grains or brassicas making it a very affordable way to boost fall grazing and/or feed stores. Annual ryegrass can be drilled at a rate of 20 to 30 pounds per acre at a depth of ¼ to ½ inch.

Cereal Grains – Winter grains are also great options for fall forage. Winter triticale, wheat, and rye can produce large quantities of biomass in the fall prior to going into dormancy for the winter. They can also provide early spring forage that can be harvested or grazed prior to planting corn or soybeans. Oats are another annual forage option. They can also be planted in the fall but will winterkill in northern New England. Forage specific varieties are available. These tend to have wider, more palatable leaves but also tend to be more expensive than grain varieties.

Grains may be seeded with a grain drill into a well-prepared seed bed or seeded with a no-till drill at a rate of 125 to 150 pounds at a depth of about 1 inch. Plant these winter grains as early as possible to maximize fall forage production. Grains planted later than mid-September will not yield much, if any, forage this fall. For more information on managing winter grains for forage see the following fact sheet:

Brassicas – Forage brassicas, such as turnips, kales, and radishes, can provide plenty of high quality fall forage. They may be seeded alone or in combination with other annuals, and they can yield 1500 to 2000 pounds of dry matter per acre. Brassicas are highly digestible and therefore, need to be grazed with caution to avoid bloating. Animals should only be allowed to graze brassicas for short periods of time and given adequate fiber. Brassicas can be drilled at a rate of about 6 pounds per acre at a depth of ¼ to ½ inch. 

Other Species and Mixtures – Forage peas can also provide significant biomass and quality forage with high protein and fiber digestibility. Forage peas grow more upright and are more productive than winter peas. However, they tend to do best in combination with a taller grass they can hold on to like oats. Oat/pea mixtures grow very rapidly and can produce 1.5-2.0 tons of dry matter per acre. The addition of the peas can decrease the overall fiber content, increase protein, and increase fiber digestibility and palatability. However, it will only increase to a point and the forage pea seed can be costly so don’t overdo it! Decent yield and quality can be obtained using a 50:50 or 60:40 oat:pea mixture seeded at about 100 lbs per acre and a depth of 1-1.5”. Whenever planting legumes, don’t forget the inoculant for optimal N fixation.

Brassicas can also be used in combination with cereal grains or annual ryegrass and, like forage peas, will increase the fiber digestibility of the mixture. Brassica seed is very small, so only a few pounds are needed per acre when mixing with grasses.

Legumes such as clovers and vetches can also be included in mixtures, however they tend to grow more slowly than the other species mentioned and therefore won’t provide a lot of forage this fall. Sometimes they may be added into other cover crop mixtures intended to overwinter and growth the following season. Consider your goals and if these fit into your system before you add the extra expense to your forage mixture.

For More Information – For current research on using cool season annual forages, see our recent reports:

Determining the sex of hemp plants

Hemp grown with the purpose of maximizing cannabinoid and terpene content is done exclusively with female plants to maximize quality and yield of flower material. With male plants present in this type of production system, pollen will be produced and fertilize female flowers. This will result in plants focusing more energy towards seed production, resulting in diminished quality and cannabinoid content. In order to prevent this, it is important to frequently scout and rogue male plants from fields.

Scouting and removal of male plants should begin at the 4-6 week mark and continue throughout flowering as needed. In order to determine the sex of a plant, look along nodes of individual plants where side branching occurs to observe the formation of male or female flowers (Image 1, above). This may be easier with a hand lens and pre-flowers may initially be covered by a sheath at nodes. Pulling this back during this period may reveal a cluster of male flowers or female flower. Female flowers will first become apparent by the formation of the pistils, which look like two small white hairs emerging from nodes. As these mature they will begin to die back and turn brown. These are the portions of the female flower that are receptive to pollen produced by male flowers. Male flowers will begin forming at nodes in clusters (Image 2). These will initially look like small capsules encased by the male flower sepal before opening. After opening, pollen bearing anthers will begin to mature and develop pollen for dispersal by wind. Pollen from hemp plants has the potential to travel 5km or more with individual plants producing as many as 350,000 individual pollen grains or more.

  • With the potential for a single male plant creating such massive amounts of pollen, removal of undesirable males from a flower production system becomes crucial to maintain a high-quality crop. Males may be present even while growing hemp from feminized seed (though the chance is far less with most feminized seed producing 99% females) and male flowers may develop when plants are grown under stressful conditions resulting in hermaphroditic plants. Now’s the time to start scouting your crop for male and hermaphroditic plants and ensure you end up with the best crop possible. Time to go rogue!

2020 Cover Crop Assistance Applications

The deadline for 2020 cover crop assistance applications has been extended to AUGUST 7, 2020. Applicants are advised to apply online when able to do so if you have not done so already.

Apply Now The payment rates vary by practice type (information and payment rates) and applications are due for each practice at least 30 days prior to implementation. There is a maximum of $8,000 available per farm operation from July 1, 2020 through June 30, 2021. Farm operations that meet the threshold for the Required Agricultural Practices are eligible to apply; operations must be in good standing with water quality regulations (do not owe the Agency of Agriculture, Food and Markets any funds, and are not in final order in enforcement) in order to receive financial assistance.

Cover crop payments for 2020 and recommended planting dates and seeding rates are detailed here: Broadcast or Interseeded method with a payment rate of $30 / acre, plant by October 1st at a seeding rate (may vary) of 100 lbs per acre for Winter Rye; Drilled or Otherwise Incorporated methods with a payment rate of $45 / acre, plant by October 15th at a seeding rate (may vary) of 75 lbs per acre for Winter Rye; and Helicopter Seeded method with a payment rate of $35 / acre, plant by October 1st at a seeding rate (may vary) of 100 lbs per acre for Winter Rye. NOTE*The recommended seeding rate will vary for alternative cover crop species and mixes. You should contact your local agronomist or crop consultant for comparable cover crop soil coverage rates when planting cover crops with a mixture of species and varieties.

The Agency advises farmers to plan ahead as best as possible for implementation of agronomic practices, especially when seeking financial assistance. Any applications that request funding for a specific practice are only eligible for funding as detailed on their application and grant agreement.

If you have specific questions about practice eligibility, or how the FAP program works, you can contact Clark Parmelee at 802-661-8284 or learn more on the FAP program webpage.

If farms need assistance on their applications, please contact me at the phone number below so we can help! Kindly, Nina Gage 802-622-4098 Vermont Agency of Agriculture Food and Markets Water Quality Find us on social media:

The European Corn Borer in Hops and Hemp

As the production of hemp and hops grows in the northeast, pests such as the European corn borer (ECB), Ostrinia nubilalis, are increasingly problematic for these crops. As the name suggests, ECB are a major pest of corn, though they can be damaging to hundreds of plants. The ECB caterpillars feed on and weaken plant stems, which can cause them to break, ultimately reducing quality and yields. If corn planting is delayed, ECB may shift to alternate hosts. Depending on the year, farmers have reported varying degrees of damage. Crops located near corn fields can be at higher risk. It is important to understand the lifecycle of the ECB, so proper monitoring and control measures can be put into place to minimize crop damage.

Scouting – Growers should monitor their crops for corn borers eggs beginning in early spring. Regularly scouting your crop is a cheap and easy way to monitor pest populations and potential problems that may arise. The ECB can easily be managed in their egg and larval stages, but once the caterpillars enter the stem or bine, they are more difficult to deal with. To scout your hemp and hop plants, examine the top and bottom of the leaves, on low and high portions of the plant stems. Choose random plants throughout your fields and hop yards to gain a representative view of the entire planting.

The ECB moth flights in June and August can also be monitored using pheromone-baited Scentry Heliothis net traps. Place two traps at least 50 feet apart along the edge of your field or hop yard, with the bottom of the trap above the top of grassy weeds, no higher than 4 inches above the vegetation. Avoid placing them over bare ground. Because there are two strains of ECB found in New England (New York strain and Iowa strain), bait one trap with a lure for each. Be sure to check the traps once or twice per week, and replace lures every other week. Several states in the Northeast maintain ECB monitoring networks geared towards sweet corn production (for example NY:, PA:, so you can get a general idea of when the ECB flights are occurring in our surrounding region. However, ECB distributions are notoriously patchy, so it is important not to become over reliant on data from other states, or even regions within states.

For more information on the Life Cycle and Management of corn borers, please read the European Corn Borer fact sheet found on our web site –

Watch out for Slugs!

The cool and damp start to the season we’ve had not only impacts the germination and growth of young corn and soybean plants, it also can leave them vulnerable to pests like slugs. Fields with heavy residue from weeds or cover crops, especially no-till fields, are at higher risk of harboring slugs. This is due to the residue covering the soil surface holding in moisture and cooling its temperature, creating an ideal habitat for slugs. Research in PA has shown soil temperatures to be 1.3 to 4.3 degrees cooler when planting into high cover crop biomass (Reed et al., 2019).

Adult slugs typically lay egg masses in the fall in the soil. However, some may hatch and overwinter as adults laying eggs in the spring. Mild winters and high residue can provide extra protection, leading to increased populations the following spring. Juvenile slugs hatch in mid-spring, typically in May in northern regions, and begin feeding within a couple weeks. The slugs continue to feed on crop foliage and other residue throughout the summer and typically are mature enough to lay eggs by the fall.

Seedling defoliation from slugs can happen very quickly given the right conditions. Therefore, it is important to scout fields even before the crops begin to emerge. Look for slug eggs on the soil or residue that look like very small pearly orbs (Image 1). Juvenile slugs look just like adult slugs but are very small (Image 2).

Image 1 (left). Slug eggs. Image 2 (right) Juvenile slugs. Source:

As soybeans emerge, slugs may feed on the cotyledons causing irregular shaped holes (Image 3). As the plants grow, damage can be seen on the leaves (Images 4 and 5).

Image 3 (top image). Slug damage to soybean cotyledon.Source:

Image 4. Slug damage on young soybeans.  Source: 

Image 5. Slug damage on young corn. Source: Sara Ziegler, UVM Ext.

Because the growing point of a young corn plant remains under the soil surface and protected by the leaf whorl for some time, corn often is able to outgrow early slug damage. However, in soybeans, where the growing point is above ground and exposed to slugs, damage can be severe if it occurs at the right time and slug pressure is high. Scouting can help inform the grower as to relative slug pressure and can identify a serious problem early, allowing for replanting if necessary. Slugs are most active at dawn and dusk when moisture tends to be high and temperatures are cooler. Because the eggs and juveniles are so small, care should be taken to look very closely under residue and on and around seedlings. Unfortunately, there currently are no economic thresholds for slugs on either corn or soybeans to use as guidelines when scouting.

Management tactics for slugs are limited and may not fit within some cropping systems. However, there are some simple cultural practices that may help. Tillage can bury eggs and destroy slugs, however, obviously this is at odds with the goals of no-till cropping systems and will not be an acceptable control method. Within no-till systems, it may be possible to adjust equipment to provide better residue management (i.e. row cleaners) and can help dry and warm the soil allowing for faster crop growth. Additionally, ensuring that the furrow is closed can help as an open furrow can allow slugs to travel more easily from one plant to another. Spiked closing wheels can help close the furrow and disrupt slug travel patterns between plants. Another alternative may be shifting planting dates. Planting earlier when slugs have not yet hatched may allow for the crops to emerge and grow to a point where they can overcome the later heavier slug pressure. If planting prior to slug hatch is not possible, later planting dates may be considered when temperatures are warmer allowing for faster germination and growth to outpace the slugs. Although it seems counter intuitive, using untreated seed may help combat slug populations. One of the major natural enemies of slugs are ground beetles. These insects are sensitive to neonicotinoids found in corn and soybean seed treatments such as Cruiser (thiamethoxam) and Poncho (clothianidin). Using these seed treatments when there isn’t a pest problem in the field can lead to a secondary outbreak in slugs due to harming the natural enemy population. Preliminary research at Penn State by entomologist John Tooker, has also suggested that cover cropping may actually decrease slug populations. Having a cover crop of cereal rye or clover in the field provides the slugs an alternative and perhaps preferential food source over your crop. Additionally, having a cover crop provides habitat for natural enemies like the ground beetles that can help control the slug population.

If all else fails, there are two chemical slug control options: metaldehyde and iron phosphate. Metaldehyde causes the mucus-producing cells within the slug to burst, causing death. Products typically contain 3-4% metaldehyde and are mixed with a food-based carrier to bait the slugs into ingesting the chemical (Image 6).

Image 6. Slug baits containing iron phosphate or metaldehyde Source: Hollingsworth et al., 2013

Iron phosphate causes slugs to cease feeding causing death in a matter of days. Similar to metaldehyde products, iron phosphate is typically mixed with food-based bait carriers. Iron phosphate is less effective and more expensive than metaldehyde,Wawtch but is approved for use in organic systems. When using either product it is important to apply the material evenly to provide the best control. Continuing to scout following an application can help you determine if the control is working. These chemical controls also do not harm natural enemy populations as seed treatments can.

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