Horticulture News

MycoApply-Article-Banner-800x450

Is Treating with MycoApply® Mycorrhizae Cost Effective in a Greenhouse or Nursery?

By Blair Busenbark, Sales and Commercial Marketing Manager

When I visit a greenhouse or nursery and share with professional growers the value mycorrhizae can offer them in their operation, it often comes down to two simple questions:

“Can my nursery or greenhouse simply add MycoApply® into our production protocol?”

-and-

“What is the value proposition for the use of MycoApply® mycorrhizae?”

Since MycoApply® mycorrhizae can be included in the production process in a variety of ways, the first question is often quickly resolved. We offer both granular and powder mycorrhizal inoculants can be incorporated in a growing media. This can be done by the grower directly, or the incorporation can be done at a commercial soil mix supplier. Often the option that makes sense in many commercial operations is to apply our suspendable powder mycorrhizal inoculant product options as a liquid drench. For some growers the drench can be applied in the planting line, or once the plants are placed in the greenhouse. Smaller growers have adopted the use of a plug dip to apply the liquid mycorrhizal suspension. This method works for growers that bring in most of their plant material in plug or propagation trays. Bare root transplants can also be dipped. The versatility of applications allows the inclusion of mycorrhizae in most production protocols to be seamless.

The issue of grower profitably has been in the forefront recently, since Dr. Charlie Hall completed a research study for AmericanHort. In the 2018 article titled, “An Index of Prices Paid by Growers in the Green Industry”, Dr. Hall summarized “The cost of producing nursery and greenhouse crops is about 1/5th higher in 2017 than it was in 2007.” This would not necessarily be of such importance if it were not for the fact that the green industry has held prices to their customers relatively flat over the same period of time. The combination of these factors has reduced the overall profitability of the ornamental horticulture growing industry. Growers have responded to this by trying to reduce costs, and if possible, raise prices.

Now you are probably wondering how mycorrhizae fit into this economic discussion? Before I connect the dots, I need to quickly review the documented benefits of mycorrhizae for plant growth and performance. Close to ninety five percent of all plants form relationships with mycorrhizae. In nature it is a survival response. Mycorrhizae provide a major benefit when they become associated with a plant: they expand the root mass of the plant. This expanded root mass comes from the development of a hyphal network of microscopic mycelium in the soil, which is attached to the plant’s root system, and becomes a living extension of the roots. The increase in root mass helps the plant in two major ways: First it allows the plant to be more effective in the uptake and utilization of nutrients. And secondly, the larger root mass increases the efficiency in the uptake and utilization of water.

These two major benefits from the use of MycoApply® mycorrhizae reverberate into a collection of benefits for the grower, the retailer, and ultimately the end user, whether they are a landscaper or a home gardener. These benefits vary depending on the grower and their customer base. Some of the more common benefits from mycorrhizal usage in a greenhouse or nursery are:

  • Improved water uptake by the plant leads to reduced water stress and wilt during production and at retail. This results in less plant loss, higher plant grade out, and improved retail shelf life.
  • Increased efficiency in the uptake of nutrients results in a higher utilization of the fertilizer you apply, reduced N and P runoff, temporary fertilizer reserves (part of the mycorrhizae structure) during time of shortage, and the ability to transform nutrients into a usable form for the plant. This results in the potential to grow with less fertilizer, less environmental issues, and improved retail shelf life.
  • Reduced crop time is often reported by growers that use mycorrhizae, as the increased root mass allows the plant to focus on its primary objective of flowers, yield, and/or maturity. This results in lower production costs and improved profitability.
  • More saleable plants is a key benefit from mycorrhizae use, with less loss during production, improved crop uniformity, and reduced transplant shock as you bump plants up to larger containers. This results in higher plant grade out and improved profitability.
  • Enhanced shelf life at retail, as plants come off the truck looking better, with nutrient and water reserves stored in the mycorrhizae improving plant appearance, and reducing transplant shock experienced by the end user. This results in better retail performance, fewer product returns, and increased customer/end-user satisfaction.
  • Bolstered overall plant health. Mycorrhizae are not an EPA registered product (and therefore make no claims regarding disease or pest resistance), but we all know that if a plant has better roots, it is a healthier plant, when the plant is less stressed, it becomes less susceptible to plant diseases and insect issues. University research also supports mycorrhizae positively improving a plants ability to repel root diseases.

After reviewing the major benefits from the use of mycorrhizae, it can be complex from a grower’s perspective to put an exact dollar value on those benefits. But the evidence is clear that the benefits can be significant, and those same benefits can have a significant positive impact on a nursery or greenhouse operation’s financial bottom line.

So you are probably asking yourself: “How much does it costs to use mycorrhizae?” Before I answer that question, I need to review two factors that impact the financial model for mycorrhizal use. First, once a plant is treated and colonized by the mycorrhizal fungi, the mycorrhizae will remain with the plant’s root system for the rest of the plant’s life. Until recently, most of the mycorrhizae used in greenhouses and nurseries was incorporated in a finishing mix. However, the most cost-effective and grower-beneficial practice is actually to introduce the mycorrhizae at the time of propagation. Since dosage is based on soil volume, applying mycorrhizae in the plug or propagation tray makes the most financial sense since that is when the soil volume is the smallest. Second, it typically takes eight weeks for the benefits of mycorrhizae to more easily be recognized by the grower. If you start the clock at the time of seeding or propagation, then the relationship can start in a smaller soil volume, and once established, the mycorrhizae stays with the plant as it is moved to a larger soil volume container. And it is here in the larger soil volume that the benefits of mycorrhizal usage become more and more apparent.

With all of the above information presented, I can now get to the cost of application. The cost of application for a plug or propagation tray varies based on which tray is used and application method is chosen. The cost for the grower ranges from $0.03 to $0.10 cents per tray to treat with mycorrhizae. When you start to divide the cost per tray by the number of plants per tray, the cost per plant is often less than 1/10th of one cent to treat a single plant. That cost is a pretty small price to pay considering the potential plant performance benefits and input reductions outlined in this article.

In summary, for a grower to maximized the benefits and minimize the costs, it is best to treat plants with mycorrhizae during their plug or propagation stage. Inclusion of mycorrhizae in a production protocol is an important tool for growers to use to reduce their costs and strengthen their bottom line.  With all of this information, it is easy to conclude that yes, it is cost-effective to utilize this technology, and the returns far outweigh the costs.


ProGibb-TO-Article-Banner-v1.1

ProGibb® T&O: Use of Gibberellic Acid in Ornamentals, Cut Flower, and Turf

Gibberellins

Gibberellins (or gibberellic acids; GAs) are a family of compounds based on the ent-gibberellane molecular structure that possess plant growth regulating activity. GAs are known to be regulators of many phases of higher plant development, including seed germination, stem growth, induction of flowering, pollen development and fruit growth. At present, there are 136 GAs, designated GA1 through GA136 that have been identified from 128 different species of vascular plants, and also from 7 bacteria and 7 fungi.

GAs were first isolated and identified in Japan in 1926, as a metabolic by-product of the plant pathogenic fungus Gibberella fujikuroi. The presence of GAs in this fungus leads to the extensive growth of infected rice plants. Thus, from the time of their discovery GAs were known to be effective in promoting stem elongation. In nature, GAs are synthesized in rapidly growing regions of the plants, i.e., young tissues of the shoot and developing seed.

For commercial use, GAs are produced in large industrial scale through fermentation. The most commercially available gibberellin is GA3. The beginning of commercial production of GA3 dates back to the 1950s when research on the use of plant growth regulators was booming. The most studied effect of gibberellins at that time was growth promotion and stem elongation (Fig. 1).  Since then, several other effects of GAs have been identified and commercialized.

ProGibb Fig. 1
Fig. 1.
Repeat applications of gibberellic acid cause stem elongation in brassica plants; left plant treated with GA3 and plant on the right was untreated (photo ca. 1957, Michigan State Univ.)

Physiologically, a major function of gibberellins in higher plants can be generalized as stimulating organ growth through enhancement of cell elongation and, in some cases, cell division. In addition, gibberellins promote certain developmental switches, such as between seed dormancy and germination, juvenile and adult growth phases, and vegetative and reproductive development. In this last case, gibberellins may promote the vegetative or reproductive state, depending on species.

ProGibb T&O

ProGibb T&O is a liquid plant growth regulator with 4% GA3 as active ingredient. ProGibb T&O can be used to manage important plant growth developmental processes in both organic and traditional greenhouse and nursery production. ProGibb T&O is registered for use in every state of the US. The product is OMRI-listed and approved by the USDA for use in organic production. ProGibb T&O is registered for use in several ornamentals, cut flowers and turf. The various ornamental uses, crops, use rates and application timings are summarized in Table 1 below. The most important effect of GA3 in these crops is the increase of flowering. In most cases, plants require cold (dormancy) or use changes in day-length (photoperiod) as cues for the initiation of flowering. Gibberellins have been shown to act as secondary messengers in these processes and external application of GA3 can substitute these environmental stimuli.

Table 1. Registered Uses of ProGibb T&O in Ornamental Crops

Use objective Crop/Variety Rate (ppm a.i.) Application timing
Break flower dormancy (as a partial replacement of cold treatment) Azalea 250-500 Applications begin after plants have received 3-4 weeks of chilling. For three consecutive weeks apply a single foliar application.
Inhibit flower bud initiation during vegetative growth Azalea 100-750 Apply a single foliar application beginning 2-3 weeks after each pinch. Continue applications on a weekly basis for 1-2 weeks after the first application.
Increase flower number per rhizome/tuber Calla lily 500 Soak rhizome/tuber for 10 min prior to planting.
Substitute chilling requirements and increase bloom size Camellia 2% solution Remove the vegetative budimmediately adjacent to or below the floral bud. Place a single drop of solution to the vegetative bud scar.
Increase flower number and flower size Geranium 1-5 Apply a single foliar application when inflorescence first begins to show color.
Flowering advancement Geranium 5-15 Apply a single foliar application when first bud set is noted.
Elongate peduncle Pompom Chrysanthemum 25-60 Apply a single foliar application 9-12 weeks prior to expected date of sale.
Accelerate bloom and increase the number of flowers per plant Spathiphyllum 150-250 Apply a single foliar application to the flower buds 4-5 weeks after initiation of short days.

ProGibb T&O is also registered for use in cut flowers (Table 2). The main purpose of application is the promotion of stem elongation and increase in the number of flowering stems. These characteristics are of high ornamental and economic value of cut flowers. The active ingredient, GA3, increases stem elongation through the elongation/enlargement of plant cells.

Table 2. Registered Uses of ProGibb T&O in Cut Flowers

Use objective Crop/Variety Rate (ppm a.i.) Application timing
Promote stem elongation and break dormancy Aster 50-100 Make 1-3 applications during the early vegetative period. Apply when plants are 2-6 inch tall. Keep applications 2-3 weeks apart.
Accelerate plant growth, increase number of flowering stems, increase flower number and uniformity Baby’s Breath (Gypsophila) 150-500 Apply 3-4 applications at 4 weeks of growth (after pinching). Keep applications 2 weeks apart.
Promote plant growth and stem elongation Column Stock (Matthiola), Delphinium, Larkspur, Queen Anne’s Lace (Ammi), Statice, Sweet William (Dianthus) 50-100 Apply as a foliar spray when plants are 4-8 inch tall. Keep applications 2-3 weeks apart.

Besides the above-listed specific ornamental uses, ProGibb T&O can be used in bedding plants, annual and perennial potted crops (e.g., tree form azalea, flowering chrysanthemum, poinsettia), field grown ornamentals and bulb crops to promote plant growth. Applying ProGibb T&O as a single foliar spray at 1-25 ppm rate has the potential to dramatically promote plant growth of most dicot and some monocot plants. Additionally, ProGibb T&O can be utilized to overcome over-applications of growth-inhibiting plant growth regulators.

ProGibb T&O has been registered for turfgrass use. Foliar applications of ProGibb T&O have been shown to initiate or maintain growth and/or prevent color change during periods of cold stress on Bermudagrass grown in golf courses, parks and turf farms (Table 3).

Table 3. Registered Uses of ProGibb T&O in Turfgrass

Use objective Crop/Variety Rate (grams per acre) Application conditions
Initiate or maintain growth and prevent color change during periods of cold stress and light frosts Bermudagrass (Tifdwarf, Tifgreen and other cultivars) 10-25 Apply 10 grams a.i./acre weekly or 25 g a.i./acre biweekly in 25-100 gallons of water /acre.
Maintain or enhance regrowth of golf course bermudagrass during summer months Bermudagrass Tifdwarf, Tifgreen) 1-3 Apply 1-3 grams a.i./acre weekly in 25-100 gallons of water /acre.


General Use Recommendations

  1. ProGibb T&O is a potent plant growth regulator. First, evaluate product efficacy on a small number of plants before application of the product on a large scale production area.
  2. Plants are highly responsive to gibberellic acid applications and sensitive to the rates, timings and volumes of application. Care must be used in measuring, diluting and applying ProGibb T&O. Deviations in rates, timings or water volumes from the label directions will result in undesirable effects.
  3. If desired plant results are not achieved, a reapplication or an increase in rate is warranted.
  4. For optimum effectiveness, thorough spray coverage must be achieved; only plant parts covered with spray solution will be affected. Plant parts not directly covered with ProGibb T&O will not respond to the application.
  5. An effective dose of ProGibb T&O is strongly dependent on application volume. Variation in plant response is possible if a given rate is applied at different spray volumes. Uniformity of spray solution is equally important.
  6. When applying ProGibb T&O foliarly, spray plants to run-off. The actual spray application rate will vary depending on plant size and spacing den­sity.
  7. ProGibb T&O is most ef­ficacious when applied in slow drying conditions, i.e., during morning or late afternoon hours. Slow drying conditions provide longer direct contact of the spray solution with the plant surface resulting in better absorption of the product and thus greater efficacy.

MGK-Article-Banner-v1.2

Managing Whiteflies and Aphids with MGK’s Botanical Insecticides

Aphids and whiteflies actually have a lot in common. Whiteflies are not actually flies at all. In fact, both aphids and whiteflies are in the order Hemiptera and suborder Sternorrhyncha so they are fairly closely related, as far as insects go, and many of the control techniques work similarly on them. They are similar in size, both soft bodied, and have piercing sucking mouthparts. Some differences are that whiteflies are winged and although aphids are sometimes winged, most often they are not. Whiteflies often are covered in tiny waxy scales giving them that bright white appearance, while aphids are not but come in a variety of colors such as yellow, green, black, and even pink. If you are unsure about whether you have whiteflies or aphids, you can take them to an entomologist for identification.

Aphids and whiteflies seem to be an ever present or at least frequently reoccurring pest that every grower I know has dealt with at one time or another. You are not alone! These tiny yet fierce little creatures can wreak havoc on your plants.

There are many different tactics and options to consider when trying to manage these pests including cultural controls, biological controls, exclusion, and physical removal. For this article we will focus on MGK’s botanical insecticides. Contained in your arsenal of botanical options are EverGreen Pro, PyGanic Specialty, and Azera Gardening. They have some key differences I will discuss below.

Botanical Whitefly and Aphid Control Products:

EverGreen® Pro 60-6 is a botanical product that contains the synthetic synergist piperonyl butoxide (PBO) as well as the botanical active ingredient pyrethrins. The product is 60% PBO and 6% pyrethrins. They work together to create a more effective insecticide for the whiteflies and aphids. The PBO binds to enzymes and prevents them from breaking down the active ingredient inside the insect. This allows the insecticide to have a more powerful and lethal effect on the insects without adding more insecticide.

PyGanic® Specialty is an OMRI listed product containing 5% pyrethrins. If you want or need an organically certified product for professional plant production, then this one will work for you. It has the same active ingredient as EverGreen Pro 60-6, but without the added synthetic synergist.

Azera® Gardening is an OMRI listed combo product containing azadirachtin and pyrethrins. It contains 1.2% azadirachtin and 1.4% pyrethrins. The dual action active ingredients provide different modes of action that can combat potential resistance or delay the development of resistance. Azadirachtin has a little bit longer half-life than pyrethrins in most situations although still breaks down fairly quickly. Not for use on plants being grown for sale.

When picking one of these insecticides, consider them in regards of all the factors that are important to you. Some of those factors could be OMRI listing, multiple modes of action, extra killing power of a synergist, and let’s not forget cost. To effectively consider costs, find the labels and look at how much a finished gallon per 1,000 ft2 will cost at the rate you want to apply and how many total finished gallons that container will make then compare amount of area treated per insecticide container. That will give you a better picture of cost per application rather than comparing concentrates side by side that may have different mix rates.

With all three of these botanical products there is no pre-harvest interval, with a few limited restrictions for things like cotton and rice. Therefore, with EverGreen Pro 60-6 or PyGanic Specialty you can spray in the evening and ship or sell the plants or crop the next morning. With Azera Gardening there is also no pre-harvest interval but it is not for use on plants being grown for sale. Remember to read the label carefully for the product you choose to make sure you are following all label instructions.

How and When to Apply the Products:

When do you need to apply these products? Spray as soon as you detect an infestation. It is best to nip the pest problem in the bud so to speak… or maybe literally, Ha! Seriously though don’t let the problem get out of hand. It is much easier to deal with a new infestation on a few plants (hot spots) as opposed to waiting until all plants in a planting have high pest numbers with serious damage and crop losses.

When you do find a problem and decide to spray, coverage is key. Make sure to get all the surfaces where pests may be resting or harboring. Undersides of the leaves are especially important. These insecticides are contact insecticides and they have to contact the insect in order to be effective. Multiple treatments may be necessary to get all the insects. Whiteflies and aphids are tiny and whiteflies especially are mobile and it is difficult to get all of them on the first spray. Spraying in the evening when there is less UV light can slightly extend the period of efficacy of pyrethrins. Night spraying also avoids getting insecticide on most pollinators that visit flowers during daylight.

When should you not apply these products? Do not apply them as a preventative when no pests are present because it is a waste of product. You may also quickly reach the maximum numbers of sprays allowed on a crop per season and not be able to use the product later when pests appear. Most if not all botanical based insecticides have very short period of efficacy and most insects are killed after getting covered with insecticide or on contact. Because UV light breaks them down so quickly you cannot use them to kill insects that may arrive after a spray. Pyrethrins have about an 11 hour half-life outside in direct sun. UV light is the quickest way to break down the product, but other break down mechanisms include microbes and oxidation.

Monitoring for pests is one of the most important things you can do to maintain the health of your plants. If you don’t know there is a problem, you certainly can’t do anything about it. So make a weekly schedule and look for aphids and whiteflies on yellow sticky cards (1 card per 1,000 ft2 of bench) and also randomly inspect for these pests on all parts of the more susceptible plant varieties, new plant cuttings and weeds in all parts of the greenhouse, especially by fans and doors. Mark each pest hotspot with flagging for future insecticide treatment and/or inspection. Also, implement various sanitation practices to minimize pests that may develop on weeds under benches, around greenhouse exteriors and mulch on floor.

Sandra Sleezer

MGK – Technical Service Coordinator

January 12, 2018

Acknowledgements: Sandra would like to thank Dr. Donn Johnson, professor of entomology at the University of Arkansas, for his contributions in editing and improving this article to the benefit of those who will read it.

© 2018, Mycorrhizal Applications LLC


MycoApply-Article-Banner-v1.3

Have You Considered Using Mycorrhizae?

Why Mycorrhizae, Why Now?

Mycorrhizae are not new, in fact they have been around for hundreds of millions of years.  But the knowledge of how a horticultural professional can successfully use mycorrhizae has been emerging more and more in recent years. When plants started to associate with mycorrhizal fungi in nature, the symbiotic (mutually beneficial) relationship formed to help plants to survive under stressful conditions.  Today, growers need to consider using mycorrhizae to be more competitive in today’s ever-changing marketplace.

Every grower is unique, depending on their production capabilities, customer base, etc.  The benefits of using mycorrhizae in your production system and as an active ingredient in your finished product are also unique. To keep it simple, mycorrhizae expand a plant’s root mass. And by expanding a plant’s root mass, the mycorrhizal fungi are able to supply inorganic nutrients and water movement to the plant, and in return the plant ships surplus sugars back to the mycorrhizae.

Benefits that Matter to the Grower

Now how does that benefit a grower that produces plants in an ideal environment where nutrients and moisture are never lacking? Mycorrhizae allow your plants to be more competitive in the sequestering of the nutrients and water that you are providing to your plants. Even when water and nutrients are not deficient, mycorrhizae still expand the root masses of the plants and provide benefits.

A plant without mycorrhizae typically uses a small portion of the nutrients that are applied by the grower.  Mycorrhizae greatly increase the percentage of nutrients absorbed by the plant. The fungus does this in two ways. First they extend their mycelium network beyond the normal root zone and secondly, they extract more nutrients within the root zone because the mycelium is finer than plant roots or root hairs thus improving the overall nutrient uptake due to the increased surface-absorptive area. They also have the ability to transform nutrients into forms that plants can more readily absorb. For example, they can secrete organic acids that dissolve or chelate many ions, or release them from minerals and converting these nutrients into available forms that the plants can use. This is especially important in root-constrained situations i.e., in containerized plants, where roots are limited to a small volume and there is no possibility for the roots to explore larger soil volumes. Additionally, mycorrhizae can store nutrients when they are in excess, and supply them to the plant later when they are needed.

Since commercial growers began utilizing mycorrhizae in the 1990’s, we have learned a lot about plant nutrition. Where the norm used to be using a 20-20-20 fertilizer, to now when growers use a 20-10-20 fertilizer, or better yet a 15-5-15 or 15-2-15 fertilizer and grow in soil-less media to produce the same crop. With these changes, nitrogen levels have dropped from historic levels of 200-400 ppm N to 100-150 ppm N by comparison. As growers have reduced their nitrogen levels, their phosphorus levels have dropped, as well.  Historically, these higher levels of water-soluble nitrogen and phosphorus have suppressed mycorrhizal activity because there was no mutual need of the host plant and fungus to form a symbiotic relationship.

All of these nutritional changes have created plants with stronger/harder shoot and root growth, a greater resistance to plant disease and reduced fertilizer costs for the grower. The advent and increased use of controlled release fertilizers and organic fertilizers have also changed the landscape. All of these changes have opened the door for the use of mycorrhizae. Mycorrhizae allow plants to do more with less.  Growers can reduce their fertilizer usage on a finished crop by 25-40% and still deliver the plant quality desired by retailers. The reduction in fertilizer and the greater utilization of the fertilizer by the plant also reduce nitrogen and phosphorus run off. What is amazing is that growers that do not reduce their fertilizer usage will still benefit from the use of mycorrhizae, because their plants will use more of what is applied and less will go to waste through the bottom of the pot. The expanded root mass derived from the use of mycorrhizae also benefits the plant by allowing it to access more of the moisture applied to the plant. This can also benefit the grower when they are struggling to get caught up with their watering due to warmer weather during production.

Benefits to Your Customer, the Retailer or Landscaper

Once your plants are loaded on a truck and out of your care, they typically start to decline in quality due to the lack of nutrition and moisture. Growers that grow with mycorrhizae benefit in that once the plant is treated with mycorrhizae everyone else further down the value chain benefits from their decision. First the plant comes out of the truck looking better, because the plant could better handle stress during shipment. Second, nutrients will be available to the plant longer, as the plant accesses the last feeding, and as the nutritional stores in the mycorrhizae are made available to the plant. Third, water will be extracted by the mycelium network of the mycorrhizae combined with the water reserves stored in the same network; treated plants can typically resist wilt 24-48 hours longer than untreated plants. Fourth, plants that look better sell quicker, they have greater shelf appeal. Plants grown with mycorrhizae look better longer, thus they have a longer shelf life and there is less dump or less plants make it to the mark-down bench. And fifth, home gardeners and landscapers benefit from getting a plant that is better prepared to survive transplant shock. Once a treated plant is planted in the landscape, they immediately begin to expand their root mass. And as they expand their root mass the plant is better able to access nutrients and water and ultimately survive the transition. Long term the plant is better able to thrive, producing the desired flowers and fruits, thus creating a happy customer that returns to buy more from the grower or garden center.

Keys to Success

  • A mycorrhizae treatment does not have an immediate impact. Typically mycorrhizae need eight weeks on average to start to demonstrate visual benefits to the grower. Benefits to the plant will begin within a few weeks of treatment, but the difference will be less noticeable. Early colonization (during propagation or when the plugs arrive) is most cost-effective, as young plants require less inoculum, produce a faster response, and the eight-week clock has started to count down. This is especially important for short term crops grown in greenhouses. For landscapers, it is never too late to top-dress or incorporate the mycorrhizae to an untreated plant. Mycorrhizae can be added at planting or to an established landscape.
  • Mycorrhizal propagules need to be applied in close proximity to actively growing root tips, as the root exudates trigger the germination of the dormant propagules, and kick off the symbiotic colonization of the root system. MycoApply® can be applied as a seed treatment, applied to unrooted cuttings, incorporated into growing media, or even used as a drench or plug tray dip. The key is to mix the propagules thoroughly in the soil or to apply sufficient water volume to move them into the future root zone of the plant.
  • Mycorrhizal fungi are soil-borne fungi that may be susceptible to certain fungicide products. More information on this topic is on the Mycorrhizal Applications website. A website document titled “Effects of Fungicides on Mycorrhizal Fungi” gives an overview of our present knowledge of the compatibility of mycorrhizal fungi and fungicides. Many common fungicides are compatible with mycorrhizal inoculation and development. The inoculation stage is the most susceptible period. The longer the wait to apply any fungicide after mycorrhizal fungi inoculation, the better for the mycorrhizal development. We suggest waiting at least two weeks to avoid slowing the mycorrhizal inoculation. Most foliar applied fungicides (except systemics, such as Strike®) have little effect on the mycorrhizal fungi.
  • Diversity matters when it comes to mycorrhizal fungi. Having multiple species is critical to achieve maximum efficacy of the mycorrhizae. There are over three hundred known species of endo mycorrhizal fungi in the world. In the soul microbiome, the mycorrhizal fungal community changes over time with plant phenology, season, microclimate and soil conditions. Furthermore, different species are responsible for different functional benefits to the plant. This is analogous to why you take a multi-vitamin. Depending on the day, you might need more of a particular vitamin contained within the single pill; the same is true with plants and mycorrhizae, often the more species in the mix, the better. Independent research has shown products containing multiple mycorrhizal species provide more consistent benefits to the plant and ultimately to the grower. Even if you purchase a growing mix that has a single species of mycorrhizae already included, your plants will still benefit by being treated with a MycoApply® multiple-species offering.
  • Not to complicate things, but it is also important to treat the right plants with the correct mycorrhizae. Almost 85% of all plants are Endomycorrhizal. This includes most greenhouse crops. About 10% of plants are Ectomycorrhizal. This mostly includes conifers and hardwood trees. Orchids and Ericaceae plants have their own unique types of mycorrhizae that are not commercially available in North America. A few horticultural important crops are non-mycorrhizal. They include brassicas, spinach and the Caryophyllaceae family (Carnation, Dianthus, etc.). If you treat a plant with the wrong mycorrhizae or that is not mycorrhizal, you will not harm the plant. Click here for a list of families and genera and their mycorrhizal affiliation.
  • If you plan to run a mycorrhizal trial, you should only have one variable. The treatments should be 1) standard production practices without mycorrhizae versus 2) standard production practices with mycorrhizae. This will allow you to isolate the value that mycorrhizae offer to your business.

If you have any questions about the information contained in this article, please contact Mycorrhizal Applications at 866-476-7800 or email us at inquiries@mycorrhizae.com.

Blair Busenbark

Mycorrhizal Applications – Sales & Commercial Marketing Manager

January 12, 2018

© 2018, Mycorrhizal Applications LLC


MycoApply-Article-Banner-v1.2

Plants Grown with Mycorrhizae Shine at Retail and in the Landscape

The many benefits that mycorrhizal fungi provide to plants are extremely well documented.  In fact, mycorrhizal fungi have been called the most researched soil organisms in the world, with scholarly journal articles and published trials from countries around the globe numbering in the tens of thousands.  These symbiotic organisms have been relied upon for successful reforestation and restoration projects for decades.  In agriculture, mycorrhizal fungi are partnering with plants in symbiosis to contribute to sustainably feeding our growing global population, even in drought affected areas, salty soils, desertified farmland, etc.

Professional horticulturists, including greenhouse and nursery growers, can also experience the benefits of mycorrhizae in their own growing protocols.  However, these benefits can sometimes be harder to demonstrate in horticultural circumstances, since plants are less likely to experience stress in a greenhouse or nursery, as the growers are giving them everything that they should need to thrive, including plenty of water and nutrients.  Most ornamental plants will show some additional growth as well as improved root structure and plant habit when inoculated with mycorrhizal fungi, even within the short turnaround time that greenhouse or nursery growers will have their plants in production.  However, when comparing mycorrhizal treated plants with non-treated controls in the greenhouse, these differences may not always look like they will impact the bottom-line.  But, as soon as these treated plants leave the grower, this is where the benefits of mycorrhizal inoculation really begin to shine, and these benefits positively reflect back to the grower.

Increase Plant Resilience in Transport and Retail:

Ornamental plants are delicate beauties.  They are babied from the time of propagation, and ideally, are provided with the perfect environment to optimize growth and development.  Before heading out into the world for retail sale or landscape installation, they will certainly be watered to prepare for the journey, but this may be the last water they see until reaching their destination.  The stress of being packed into a dark truck on crowded racks, with the potential for extreme heat or cold and little or no air movement, may be their first shock and can have an impact on how they look on the retail shelf.

Then, once they make it to the garden center, box store, etc., they are handed off to a new situation and staff who may or may not be capable of continuing to providing those ideal conditions that the plants had become accustomed to.  The heat and drought of a retail situation can cause a good deal of plant wilt, blossom and foliage damage, and even mortality, making them less and less likely to be chosen by a homeowner or landscaper off the shelf.  This is where the inoculated plants really start to stand out, as they are more resilient and will resist wilt for 24-48 hours longer than untreated plants, and will recover from wilt much more quickly once the staff gets the chance to make the rounds.  This means higher sell-through for “pay by scan” growers, and fewer dumped or discounted plants, which is a good thing for everyone in the pipeline.  For the grower retailer, mycorrhizal inoculation means that your plants will look better in the shop, survive longer on the shelf, and ultimately improve the customer experience with your brand, as end-users will experience less transplant shock, less mortality, and greater overall success and satisfaction with your mycorrhizae inoculated plants.  Also, any retailer that has a plant guarantee will see less loss at transplant and fewer returned plants, which reduces the costs for the retailer and grower of guaranteed plants.

Benefits to Home Gardeners and Landscapers:

The benefits of mycorrhizal fungi to plant resilience, longevity, vitality, and overall performance are passed along from the grower to the end-user, whether it happens to be a home gardener or landscaper.  Home gardeners, especially inexperienced “casual” gardeners, will have more success in the garden with less effort, leading to return trips to the retailer and additional purchases.  And this is good for the grower and retailer as well, because when home gardeners have success, they will likely return to that same nursery or retailer for more of those “good” plants that they had so much success with.  The same concept applies to landscape professionals, who will certainly return to the source of those resilient, hearty plants that they only had to plant once, rather than having to return to a site to replace plants that didn’t successfully take root and survive in outplanting.  Plus, the landscaper’s customers will be happier, as their plants will be more sustainable, lower maintenance, and require fewer inputs such as water and nutrients to survive and thrive.

How Soon Will You See the Benefits?

The general benchmark is that it may take as long as 8 weeks to see a visible difference between mycorrhizal inoculated plants and untreated control plants, however, this varies quite a bit from species to species, with some plants showing significant differences as soon as 2-3 weeks after treatment.  As a plant producer, you will see bigger benefits of mycorrhizal inoculation if you also reduce your nutrient inputs when inoculating with mycorrhizal fungi.  This not only offers the immediate benefit of offsetting some of the costs of the mycorrhizal product, but it also leads to quicker and more effective colonization of the root zone, since plants who are over-fertilized will send out fewer root exudates to trigger the germination of the mycorrhizal propagules.  We recommend cutting back on fertilizer by around 30-40% when inoculating with mycorrhizal products like MycoApply, in order to maximize the return on investment, and reap the full rewards of the symbiosis.

Also, the earlier in the plant’s life cycle that you can inoculate the roots, the better.  If the grower can include mycorrhizal inoculants in the growing media at plug stage, or drench the propagation trays in a mycorrhizal slurry, this is the most cost-effective method, and can provide the plant with this symbiotic support for the rest of its life.  The basic guideline is this: the smaller the plant at the time of inoculation, the less product you will need to achieve mycorrhizal colonization.  Simple, right?  When inoculating at propagation stage, the cost can be as low as $0.03 to $0.04 cents per plug tray!

For a landscaper, or a retailer who does landscape installation, inoculation at plug stage may not be possible, however, these products work very well in transplanting as well.  Mycorrhizal Applications offers MycoApply products in powder formulations (such as MycoApply Ultrafine Endo), which can be drenched or applied directly as a powder to root balls during transplant, as well as granular formulations (such as MycoApply Endo), which can be applied around the exposed roots and incorporated into transplant backfill.  No matter the stage of the plant’s lifecycle, any time you can get the mycorrhizal propagules into contact with the growing roots, you can kick-off the symbiotic colonization process.

Where can I find these products and learn more about how to use them?

MycoApply professional mycorrhizal inoculants are available through many nationwide distributors.  The best way to determine where you can get your hands on some to try in your own greenhouse or nursery is to contact Mycorrhizal Applications, who can then point you towards a distributor in your region.  Their information is available online at www.mycorrhizae.com, or you can reach one of their helpful, friendly, and passionate sales staff by calling (541) 476-3985 or emailing inquiries@mycorrhizae.com.  They also have access to a library of research and resources about how to utilize this technology, so feel free to reach out with any mycorrhizal questions that could help you maximize your success.

© 2017, by Mycorrhizal Applications LLC


Actinovate-Article-Banner-v1.1

Actinovate Biological Fungicides – A Powerful and Versatile Tool

Actinovate biological fungicides offer growers and home gardeners a very powerful and versatile Organic (OMRI Listed) tool to control fungal pathogens.  Actinovate works just like other biological controls (the classic example of a biological control is the use of ladybugs to control aphids), only the organisms in Actinovate act on a microscopic level.  Actinovate uses a natural enemy of fungal pathogens to keep these pathogens from destroying your crops.  This natural enemy is a beneficial bacteria called Streptomyces lydicus WYEC 108, which is a naturally occurring soil bacterium that was originally isolated from the roots of a linseed plant in England, and patented worldwide.  Actinovate is effective and versatile, utilized both indoors and outdoors, in markets including greenhouse, nursery, landscaping, turf, and homeowners.

How does Actinovate protect against fungal pathogens?

Actinovate can be utilized to combat fungal soil diseases, as well as foliar diseases.  The organism within Actinovate colonizes plant structures in a beneficial symbiotic manner, when introduced into the root zone or applied to foliage.  The Streptomyces lydicus spores germinate and form a mutually beneficial relationship within the rhizosphere of plants by feeding off the plant’s waste and secreting beneficial byproducts, such as Chitinase to break down fungal walls, byproducts that kill or repel other microbes, and iron carriers to starve competing microbes.  Essentially, the S. lydicus feeds off the root’s secretions, and discharges toxins that keep other microbes (including pathogens) out.  This assortment of byproducts and toxins discharged by S. lydicus means that Actinovate utilizes several modes of anti-fungal action to protect plants, lawns, and gardens from pathogens, rather than relying on a single mode of action as many other fungicides do.

What pathogens can Actinovate help control against?

Similar to a probiotic used to keep our own digestive systems in healthy balance, Actinovate works within the root zone microbiome to keep the system healthy and in-balance.  Actinovate can be used on annual and perennial bedding plants and flowers, roses, potted flowers, foliage plants, trees, shrubs, and lawns located in homes, greenhouses, and home landscapes, as well as fruits including tree fruits, berries, and melons, nuts including a wide variety of tree nuts, and vegetables including leafy vegetables, root crops, cole crops, peppers, and tomatoes.

Actinovate’s S. lydicus organism will actively control against several common soil pathogens, such as Damping Off Fungus, Root Rot, Turf Brown Patch, Pythium, Rhizoctonia, Phytophthora, Fusarium, Verticillium, Sclerotinia, and many others.

In foliar applications, Actinovate will suppress Downy Mildew, Gray Mold, Powdery Mildew, Botrytus, Phytomatotricum, Sclerotinia, Alternaria, and more.

When should Actinovate be applied?

As with most biological controls, it is best to use Actinovate as a preventative tool, rather than curative treatment.  For best results, apply Actinovate as early as possible to the plant’s root system, and reapply every 2-12 weeks as needed.  In foliar applications, it is best to apply prior to disease development, or at the first signs of pathogen infection, and repeat at 7-14 day intervals to protect new foliage.

Actinovate is relatively safe when compared with many other fungicides, though caution is advised when using any pesticide.  Please read the label thoroughly for all precautionary statements and PPE requirements.  When sprayed onto foliage or used in chemigation via sprinkler or other spray irrigation, the re-entry period is only one hour, or once the solution has dried.  Actinovate can be applied up to and including the day of harvest, so the pre-harvest interval is not a concern.  Always clean application equipment prior to use of this product, and use the prepared Actinovate solution within 4 hours of preparation.

How can Growers and Gardeners apply Actinovate?

Actinovate is a soluble powder which can be added to water to create a solution and then applied to the plant’s root zone or foliage using the applications below.

For rhizosphere, or root-zone applications, the soil drench should contain 4-6 ounces of Actinovate per 100 gallons of water (1 teaspoon per 2 gallons of water for smaller quantities).  This solution can be watered into damp soils, applied to pots, base of plants, root balls, or applied to the root zone by watering the substrate with Actinovate solution until the soil is completely saturated without creating runoff (generally 1 gallon of solution per cubic foot of substrate).  In greenhouses and nurseries, Actinovate can be applied to the root zone via drip or flood chemigation using the rate of 1-12 ounces of Actinovate per 10-200 gallons of water, depending on desired application.  For soil chemigation, apply the solution only through pressurized drench (flood) or drip (trickle) systems, micro irrigation such as spaghetti tube or individual tube irrigation, hand-held calibrated irrigation equipment such as hand-held wand with injector, or ebb and flow systems.

For foliar applications, dissolve 6-12 ounces of Actinovate into 50-100 gallons of water.  Growers or gardeners can use a pump bottle, hand-held pump, backpack, or similar spray equipment to spray leaves, stems, and new shoots to wet, but not quite to run-off, providing complete coverage of the entire plant.  In greenhouses and nurseries, Actinovate can be applied to the foliage via chemigation using the rate of 1-12 ounces of Actinovate per 10-200 gallons of water, depending on desired application.  For foliar chemigation, apply the solution only through overhead boom and mist-type systems or sprinklers such as impact or micro-sprinklers.  For best results in foliar applications, use a non-ionic spreader-sticker in conjunction with Actinovate application.

Always refer to product label for complete instructions, precautions, safety, and storage and handling before use.

Can Actinovate be part of an IPM program?

Actinovate is a great addition to any Integrated Pest Management program, and can be used safely and effectively alongside beneficial fungi, such as mycorrhizal inoculant products.  Actinovate can also be used safely and effectively alongside a rotation of traditional fungicides.  Also, Actinovate does not need to be rotated, and can be used year-after-year, season-after-season, as unlike other fungicides, there are no pathogen resistance issues caused by prolonged or repeated use of biological solutions such as S. lydicus.  Actinovate is OMRI-Listed as an organic input, therefore, it is a great resource for organic growers and gardeners for organic control of fungal pathogens.  Additionally, Actinovate is Pollinator Safe, as trials have shown that exposure to Actinovate had no adverse effects on honeybees.

What Actinovate products are available for Professional Growers and Home Gardeners?

Actinovate is a proven technology that has been utilized by growers, farmers, landscapers, turf managers, and home gardeners with confirmed success for many years.  Professional growers, turf managers, and landscapers can utilize Actinovate SP for nursery and greenhouse applications.  Actinovate SP is available in 18 oz. packages, and has a 6-month shelf life.  Home Gardeners and Lawn and Garden professionals can utilize Actinovate Lawn and Garden, which is available in 18 oz. packages, 2 oz. packages, and 0.7 oz. packages, and also has a shelf life of 6 months.

Where can I find these products and learn more about how to use them?

These Actinovate biological fungicides for Professional Growers and Home Gardeners are available through distributors in the US and Canada.  The best way to determine where you can get your hands on Actinovate SP or Actinovate Lawn and Garden to try in your own greenhouse or nursery, or home lawn and garden, is to contact your local distributor.  If you have problems locating a distributor or need further information, contact Mycorrhizal Applications, who can point you towards a distributor in your region.  Their information is available online at www.mycorrhizae.com, or you can reach the Mycorrhizal Applications sales staff by calling (541) 476-3985 or emailing inquiries@mycorrhizae.com.

© 2017, by Mycorrhizal Applications LLC


MycoApply-Article-Banner-800x450

Endomycorrhizal Benefits for Professional Growers and Horticulturists

Endomycorrhizal fungi (also known as arbuscular mycorrhizal fungi, or AMF) are beneficial microscopic organisms that live in the soil and have evolved a symbiotic relationship with approximately 85% of the world’s plant species over the past several hundred million years.  These fungi predate the evolution of terrestrial plants, and it was the partnership with mycorrhizal fungi that allowed plants to begin to colonize dry land and create life on Earth as we know it.

How does this relationship between beneficial fungus and plants work?

The AMF symbiotic relationship centers on the plant’s ability to produce carbohydrates through photosynthesis and share some of these sugars with the fungus in return for otherwise unavailable water and nutrients that are sourced from the soil or growing media by the extensive network of mycelial hyphae produced by the fungus.  It’s a two-way relationship of sharing resources between two species, thus a classic symbiotic mutualism.  The endomycorrhizal fungi rely on the plant, and the plant’s performance and survival are enhanced by the fungus.

How is this symbiotic relationship established?

Endomycorrhizal fungi can colonize plants from three main sources of inoculum: spores, colonized root fragments, and vegetative hyphae.  Collectively, these inoculants are called “propagules,” and this is the standard unit of measure that is listed on most commercially available mycorrhizal products.

To colonize plant roots, these propagules must be present in the substrate and in close proximity to actively growing roots of a compatible plant.  The growing root tips emit root exudates as they push through the substrate, which signal the fungi to colonize the roots and establish the symbiosis.  Once the roots are colonized, then the process is self-sustaining as the vegetative bodies of the AMF ( the fungal mycelium) continue to grow with the plant’s root system and additional spores and hyphae are produced.

To inoculate plants grown professionally or in a home garden, AMF propagules can be incorporated into the substrate prior to or during planting or they can be top-dressed on the surface and watered into a porous substrate.  They can also be applied as a dip or slurry at the time of sticking a cutting, seeding, or at the time of transplanting.  The propagules can also be applied as a drench to the soil and watered-in, applied to the outer surface of the rootball before transplanting, or used in transplant hole and backfill soil.

How can professional growers utilize this symbiosis?

The application rates for endomycorrhizal fungi are based upon the number of propagules per volume of soil for container-grown plants and per area of coverage for turf and landscape plantings.  Therefore, large containers will require more propagules than smaller containers.  For a professional grower, it is more cost-effective to treat plants early in the crop cycle when they are growing in smaller volumes of soil, and will require fewer propagules per plant to achieve colonization.  Germination of the spores occurs relatively quickly after contact with growing roots, but full colonization of the roots can take several weeks.  Plants will reap the full benefits of the colonization within 6-8 weeks after application.  Some plant species will demonstrate the benefits of mycorrhizal colonization sooner than others.

The mycorrhizal fungi colonize the developing roots by growing into the plant’s root cells to obtain carbohydrates and simple sugars (food).  The tiny fungal mycelial threads grow throughout the available soil volume and effectively “mine” the soil for water and nutrients that the plant cannot access or absorb on its own.  The enhanced water uptake helps the plant to resist drought conditions and ensures faster plant response if its roots are damaged by adverse conditions (drought, water-logged conditions, high salts or high soil temperatures).  The mycelium also secretes organic compounds that help solubilize nitrogen, phosphorus and other macro- and micronutrients from the substrate.  These nutrients are actively transported by the fungus to the plant to produce proteins and other components needed for vigorous growth and development.

How it Works Diagram

Why do horticulturists and professional growers need mycorrhizal fungi?

With traditional input-intensive growing protocols, nursery or greenhouse grown plants are produced under optimum conditions and may be able to perform sufficiently in the short-term, without the assistance from mycorrhizal fungi.  However, water restrictions in production and landscapes will encourage growers and consumers to be water-wise and utilize mycorrhizae as part of our water management programs and promotions.  Trials have demonstrated that the use of mycorrhizae can reduce water requirements significantly by increasing the plant’s ability to utilize and store water through the AMF mycelial network of hyphae.  Consequently, retailers and growers have realized reduce shrinkage due to drought and stressful conditions in the retail chain.

There is additional pressure to reduce the runoff of nutrients, especially nitrogen and phosphorus, from nurseries, greenhouses, and landscapes.  Both of these essential plant nutrients are accessed and delivered to the plants by mycorrhizal fungi, and in many instances these inputs can be reduced significantly by utilizing AMF without a noticeable reduction in crop time, appearance, or performance.

Excess water usage results in more runoff and excess fertilization results in more pollution of the environment.  Many conscientious growers welcome beneficial biological solutions like mycorrhizal fungi to help reduce these environmentally harmful growing techniques, and this type of technology is becoming a major part of the toolkit to increase the overall environmental sustainability of the horticulture industry in the long run.

Are professional endomycorrhizal products available for greenhouse and nursery growers?

Mycorrhizal Applications, the leading producer of mycorrhizal propagules in the US, produces a suite of professional products that make it easy for growers to trial mycorrhizae and to incorporate it into their production programs.  Their flagship “MycoApply” endomycorrhizal inoculum products contain four different Glomus species of AMF for optimal diversity and performance under most growing conditions and crops.  These flagship endomycorrhizal inoculant products are MycoApply Endo and MycoApply Ultrafine Endo.  MycoApply Endo is a granular formulation containing 60,000 AMF propagules per pound and is ideal for soil incorporation, as the granular consistency blends evenly with growing media and soils.  MycoApply Ultrafine Endo is a suspendable powder containing 130,000 AMF propagules per pound which can be soil-incorporated or prepared as a liquid suspension for use as a soil drench or plug tray dip.  Whether incorporating the granular product into your media or drenching with the suspendable powder formulation, it is important to get the propagules in the root zone as soon as possible and as early in the crop cycle as possible.

 

MycoApply Endo & MycoApply Ultrafine Endo

Where can I learn more?

Plants and mycorrhizal fungi have had a long-term relationship for over 400 million years and we are just beginning to understand this relationship better and are now employing this symbiotic mutualism in professional horticulture.  You can learn more about mycorrhizae by going to Mycorrhizal Applications’ website (http://mycorrhizae.com/) or by contacting Mycorrhizal Applications directly at 1 (866) 476-7800.  Resources and literature such as Fungicide Interactions with Mycorrhizal Fungi, and the Mycorrhizal Status of Plant Families and Genera are available through their website or by contacting them directly, in order to help you determine how to include mycorrhizal fungi most effectively into your professional growing protocols.  MycoApply products are also available through many horticultural distributors throughout North America.

Hugh A. Poole, Ph. D.

Horticultural Technical Consultant

September 12, 2017

©2017 Mycorrhizal Applications LLC.  All rights reserved.


MGK-Article-Banner-800x450

Managing Mites in Professional Greenhouses

We’ve all been there… You are growing your plants in your greenhouse and everything is going great, until it isn’t. The leaves are yellowing or browning, the new growth looks stunted or cupped, and old leaves are even falling off, or perhaps you see strange growths or galls on the plants, but you don’t see any obvious pests. It is possible it is a disease, but first let’s pull out the microscope and take a closer look. You might just have mites. Broad mites, spider mites, and eriophyid mites are all common mite pests that can cause these mysterious symptoms.

How do you know for sure if you have one of these types of mites?

Pull off a few leaves, both old leaves and newer leaves that look damaged or infested, and examine them under a microscope at 10x, 40x or more, depending on how good your eyesight is. Focus on the undersides of leaves when looking for mites and their eggs.

For broad mites specifically, you need to find some eggs, which are about 0.08 mm long and covered in tiny polka dots. The closer you can zoom in, the easier they are to identify. Adult broad mites are a translucent light-green to yellowish color, and the females have a white stripe down their backs. However, the eggs are really the most obvious identifier, with that tell-tale polka dot pattern.

Broad Mite Egg Photo

(Picture from Texas Plant Disease and Diagnostics Lab website.)

Spider mites are most easily identifiable by noticing the webbing along with the mites. Adult spider mites have two red eye spots near the head and females two dark splotches, one on each side of the body, and bristly bodies and legs. The eggs are small, clear and spherical.

Spider Mite Photo

(Picture from UC Statewide IPM Project,
Copyright 2001 Regents, University of California)

Eriophyid mites are elongate and have two pairs of front legs that drag the rest of the body behind it. They can be extremely small with the smallest being around 1/100th of an inch long so that field identification is virtually impossible. They often form galls on the plants and evidence of infestation is often determined by identifying the plant damage rather than trying to see the mite itself. Also note, if these mites are currently inside a gall then pyrethrins and pyrethroids won’t affect them. They are protected inside the gall and only susceptible to non-systemic insecticides like pyrethrins when they are out and about.

Eriophyid Mite Photo

(Picture from The Ohio State University website. http://bygl.osu.edu/node/751)

If you determine that you do have mite pests, then what?

Well, there are several options. If you are able to dispose of the infested plants, that can help cut down the overall population quickly, but you still need to manage the mites that are left, and luckily there are several good options. You can use horticultural soaps or oils, or other pesticide options labelled for mites. If you choose to use pesticides, PyGanic Specialty organically derived pyrethrins or EverGreen Pro 60-6 from MGK are good options to crush the mite population initially.  These botanically-derived insecticides have a very short residual persistence, so just a few days after application, you can then introduce beneficial predatory mites into your greenhouse to keep the destructive mites from returning in force.

PyGanic Specialty is OMRI listed, it contains pyrethrins, and can be used in certified organic facilities. EverGreen Pro 60-6 is not OMRI listed. It contains PBO in addition to pyrethrins which is a synthetically produced synergist. A synergist enhances the efficacy of the active ingredient, but is not itself an insecticide. Both products are in group 3A (pyrethroids/pyrethrins) of the insecticide resistance action committee (IRAC) classification system. They are sodium channel modulators.

To reduce the risk of contributing to insecticide/miticide resistance, growers must rotate modes of action in their insecticide applications. The Insecticide Resistance Action Committee (IRAC) has classified the modes of action into groups. Some other common groups of insecticides are group 4A (neonicotinoids), group 1A (carbamates), group 5 (spinosyns), and group 6 (avermectins). Something to take note of if you rotate with a group 4A neonicotinoid is that imidacloprid is known to cause outbreaks of spider mites, and other neonicotinoids may have the same effect so they may not be the best choice for a mite application. For all of these groups and the individual insecticides in them, they will have varying levels of residual activity, and other properties that may affect pre-harvest intervals, beneficial insects/mites, use sites and a host of other factors. In addition to the properties of the active ingredient itself, the formulation also plays a big role in residual activity, use sites, etc. so make sure to read the labels thoroughly on any product you use. You can check out the IRAC website to learn more about insecticide groups and rotation of modes of action to reduce the risk of resistance http://www.irac-online.org/modes-of-action/.

One of the benefits of pyrethrins over other active ingredients is the lack of residual persistence, which means they can be applied close to or even after harvest, and the ability to reintroduce beneficials soon after application without worry. Keep this in mind when deciding whether to use EverGreen Pro 60-6 or PyGanic Specialty vs another product with a different active ingredient. There are certainly times you may want a longer residual and a different mode of action. Evergreen Pro 60-6 and PyGanic Specialty aren’t always going to be the best options, but they do have some specific times where they fit in well.

PyGanic Specialty & EverGreen Pro 60-6

If you decide to utilize insecticides like PyGanic or EverGreen Pro, there are a few key points to take note of: The half-life in direct sunlight is about 11 hours. Therefore, spraying in the evening hours is recommended to prolong efficacy. Pyrethrins are also a broad spectrum insecticide so spray when pollinators are least likely to contact the sprayed area, again evening is probably a good time in this respect also.  These products will be most effective at the early stages of infestation or to knockdown large infestations that may have gotten out of control. When applying the insecticide for the initial knockdown, good coverage is the key. Make sure all the surfaces are thoroughly covered, and try to get the solution into those hard to reach areas like the buds. (Keep in mind that if you have beneficial mites in the greenhouse, pesticides or other product applications could hurt those populations too and predatory mites may have to be reintroduced into the system after insecticide treatments.)  Then, once the population has been knocked down, the introduction of beneficial mites a few days after the botanical pyrethrins will be most effective, now that the pest population has been brought down to a low to moderate level.

How can these insecticides be applied?

There are several pieces of equipment that work well. You can use a hand held manual pump sprayer, a backpack sprayer, a cold fogger, and even some types of irrigation systems. Check the label to determine which irrigation systems are okay to apply these products with. I also want to emphasize here that coverage of the plant when spraying is key. Make sure to thoroughly spray both the top and bottom surfaces of leaves.

How can I keep the mites from coming back, once the infestation has been resolved?

Mites can also hitchhike from plant-to-plant on flying insects such as whiteflies, travel on air currents, or even be transported by clothing or equipment. So if you have whitefly problems or other potential transport methods for mites, make sure the mites aren’t spreading to other areas. Mites can also hitch a ride on people or even strong air currents. Monitor healthy plants to make sure they aren’t getting new infestations that will have to be controlled too. It would also be wise to check for mites in any nearby weeds that could harbor them, as well as closely inspecting any incoming plants for mites to prevent reintroduction into the greenhouse. Treatment is always easier when you can catch the problem early, and of course, prevention of infestations altogether is always ideal whenever possible.

No matter which treatment method you use, it is important to continue to monitor new growth closely to make sure your plants are growing normally and not stunted. Remember to monitor both healthy looking and damaged plants, as scheduled monitoring of both the pest and beneficial mite populations is critical, along with good hygiene and sanitation.

Sandra Sleezer

MGK – Technical Service Coordinator

September 14, 2017


Everybody’s Doing It—Should You? (GrowerTalks Cover Story)

by Jennifer Zurko (Excerpt from GrowerTalks, February 2017)

(Link to Original Article: http://www.ballpublishing.com/GrowerTalks/CoverStory.aspx?articleid=22821)

GrowerTalksFebCoverCapture

It’s an important word that’s hard to pronounce, but once you see the benefits of adding it to your growing media, it’ll be as simple as saying phytophthora.

At least that’s what the companies who produce mycorrhizae and the media that include it are hoping. And it seems to be working—they say more and more growers are seeing how it can help their crop go from good to great with a better root system, plant vigor and more.

Mycorrhizae isn’t a new thing, by any stretch; it’s been naturally occurring in nature since forever. And greenhouse growers knew about it 30 years ago, but at the time, no one had ever thought they would be able to use it in their own growing media. Now, with more research coming out and more companies making it commercially available, mycorrhizae is all the rage…

Continue Reading: http://www.ballpublishing.com/GrowerTalks/CoverStory.aspx?articleid=22821


New Growing Media Advancements Giving Growers More Options

By: Laura Drotleff (Excerpt from Greenhouse Grower, December 2016)

Link to Original Article: http://www.greenhousegrower.com/production/crop-inputs/media/new-growing-media-advancements-giving-growers-more-options/

A number of advancements in growing media components have surfaced over the past few years, providing growers with new options for building the best possible foundation for growing healthy plants.

Growers who are mixing their own growing media want to develop precise recipes that will ensure optimal growth for a large range of crops at an affordable price. Those who purchase pre-blends appreciate the convenience, consistency, and innovation that goes into the mixes expert growing media companies provide. These suppliers also offer the ability to mix a grower’s custom blend.

Here are some of the newest advancements in growing media components and premixes for growers today:

Click Here for Full Article: http://www.greenhousegrower.com/production/crop-inputs/media/new-growing-media-advancements-giving-growers-more-options/