CONNECT From Premier Pro-mix

 Growers are always seeking ways to help get the most out of their irrigation and nutrition plans. Many cannabis growers have turned to mycorrhizal fungi to really dial in their rootzones. This tech tip will introduce these special organisms in detail.

Mycorrhizae are soil-based plant-beneficial fungi. Mycorrhizal spores germinate and grow in the rhizosphere. The spore sends out hyphae, the fungal equivalent of roots, which seek out nearby plant roots. Through these associations, mycorrhizae deliver additional water and nutrients to plant roots, while receiving root exudates in return. Mycorrhizae gather these resources through the fine webbing of hyphae, spreading through surrounding soil. This relationship vastly expands the surface area available to plant roots for resource gathering, and aids in drought resistance and nutrient utilization.

There are two commonly utilized types of mycorrhizal fungi: endomycorrhizae and ectomycorrhizae. Ectomycorrhizae typically colonize the roots of trees and woody shrubs. Endomycorrhizae colonize the roots of most herbaceous greenhouse, food, and ornamental crops, including cannabis. Endomycorrhizae develop close associations with the roots of many plants extending the hyphae into the interior root cells. Full colonization occurs over a period of approximately 6 to 8 weeks. Short term crops such as microgreens and baby greens do not benefit as much as longer term crops such as tomatoes, cannabis, and strawberries.

Mycorrhizal products use slightly different jargon than other types of fertilizer or soil additives. Active ingredients are measured in propagules per gram or viable spores per gram. Propagules are chopped up root or hyphal fragments; products using propagules establish faster but have a dramatically shorter shelf life. Spores are survival structures produced by the fungi, take a bit longer to establish in crops, but remain viable and stable for a much longer period of time. Either type of material will result in colonized rootzones, but spore-based products offer greater protection from variations in shipping or storage environmental conditions.



CONNECT from Premier Pro-Mix contains 6000 viable spores per gram of material. Treatment with CONNECT at seeding or transplant inundates the root zone with viable spores, ensuring mycorrhizae grow into plant roots as quickly as possible. CONNECT is best applied as a 1:1 slurry of water and wettable powder at seed or transplant. As seedlings and transplants grow through the slurry of mycorrhizal product, spores germinate and grow into and with the roots. Transplants are protected from severe transplant shock, plants are better able to withstand nutrient and water stress, and overall growth is accelerated with greater access to water and nutrients. Contact your Griffin sales rep for information on availability and technical specs.

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AgSil 16H: A Source Of Silica For Both Foliage And Roots

 Silica-containing fertilizers aid in mitigating drought stress, resistance to mineral stress, and improve overall plant strength and growth. Cannabis growers can utilize silica fertilizers from day one of production to strengthen plants from beginning to end. This tech tip will explore some best practices for how to apply one such product, AgSil 16H.

AgSil 16H from Certis and other silica products require some special consideration to achieve the best application. Silica and silicate products need to be solo-injected from designated stock tanks and never tank mixed with other nutrients. Mixing highly concentrated silica products with nitrates and sulfates can lead to the formation of precipitates, which can clog lines, drippers, or filters. AgSil 16H and other silica products should ideally be injected first into the irrigation lines, before other fertilizers. It’s always a good idea to include a mixing chamber following silica injection to allow full dilution. Once fully in solution at ready-to-use concentrations, silica and other nutrients are totally compatible.

A final important consideration is pH. For many silica products, AgSil 16H included, a pH between 5.5-6.5 results in a gelling of silica when highly concentrated. Growers can either adjust stock solution pH down to between 4-5, or target between 7-8 to avoid this issue. First add AgSil 16H to water to fully dissolve, then slowly add diluted acid with mixing until the desired pH range is reached. If gelling occurs, agitate and slowly add acid until gelling has dissipated. 

AgSil 16H contains 53% silica and 32% potassium. It is best applied as a once or twice weekly drench at 1.28-2.56 oz per 100 gallons to provide 50-100 ppm Si. While grasses and other silica accumulators would likely prefer 100 ppm, Cannabis has demonstrated good responses to the 50 ppm rate. Constant injection should target around 10 ppm Si, at 0.256 oz per 100 gallons. AgSil 16H can also be applied as a foliar spray, at a rate of 1-2 lb per 100 gallons. Try adding CapSil at 8 oz per 100 gallons for improved spreading over foliage.

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Calcium & Cannabis

 The story of nutrition for cannabis and hemp goes beyond the macronutrients of nitrogen, phosphorus, and potassium. Calcium and magnesium, two secondary plant nutrients, also play important roles in plant development and productivity. Cannabis is a particularly heavy consumer of both.

What exactly are these two nutrients doing inside your plants? Calcium provides structural support to plants as they develop, strengthening cell walls as new tissue grows. Plants lacking in calcium can display symptoms such as tip burn on new growth or pronounced leaf curl. For some crops, calcium deficiency even manifests as damage to developing fruits. While calcium builds the foundations for your plants’ structures, magnesium keeps the energy flowing. Magnesium is the atom at the center of all chlorophyll molecules, enabling plants to photosynthesize. When magnesium is lacking, chlorophyll in older growth breaks down and magnesium is remobilized to new growth, leading to lower leaf yellowing.

It can be difficult to meet the full needs of some crops through the use of complete fertilizers alone. Growers find that fertilizers high in calcium can often affect the pH of their substrate, typically leading to higher pH conditions. Some growers avoid with these conditions by rotating fertilizers, while others carefully build balanced fertilizer programs. Talk to your Griffin sales rep to find out how GGSPro can help.

An additional option is selecting specialized calcium supplements without adding a complete fertilizer package. Plant-Prod MJ Spike (CaMg) is part of the cannabis-specific line of nutrients from Master Plant Prod. This product has been specifically formulated to deal with the high-calcium demands of cannabis production and can be used any time throughout the production cycle. Both calcium and magnesium are provided in a beneficial ratio of 2:1 – 5.4% Calcium, 2.7% magnesium. Chelation with EDTA keeps the nutrient ions fully soluble while in stock tanks and during application. This highly specialized product is free from any other nutrients, ensuring that other nutritional ratios are not thrown out of balance. Ask your Griffin sales rep about MJ Spike or any of the other MJ Line fertilizers from Master Plant Prod!

Suffoil-X & Mite Control

 Pest control options in hemp and cannabis can be limited– growers must either apply beneficial insects or choose from a short list of approved sprays for specific issues. Luckily, the list of approved sprays includes some versatile options, such as Suffoil-X from BioWorks. Suffoil-X, a horticultural oil comprised of mineral oil, can be used as a general insecticide, miticide, and fungicide. As with any spray, however, some care is required. Let’s review best practices when it comes to applying horticultural oils on your crops. Following these practices limits your risk of phytotoxicity or burning after spraying any oil product.

•           Always test new sprays on a small number of plants before applying to the entire crop.

•           Apply when temperatures are under 85F / 30C.

•          Ensure that foliage will dry within 1-2 hours of application.

•          Avoid spraying drought-stressed plants.

•           Remember, never mix oil and sulfur sprays!

Suffoil-X is one of GGSPro’s go-to products when it comes to curative (i.e. knockdown) sprays for mite. Once applied and the insects or mites are fully covered, spiracles (air holes) of the pest become blocked. Suffocation of pests quickly follows. A great benefit of oils like Suffoil-X is that they provide no residual action; once oils have dried, it is safe to release beneficial insects or pollinators.

    How do you know you’ve got a mite problem? Symptoms differ depending on which mites have moved in. Two-spotted spider mites are the easiest to spot and can sometimes be seen with the naked eye. Typical symptoms include a wide-spread stippling, giving leaves a dusty appearance. Severe infestations develop webbing across and between leaves. Broad mite infestations lead to severe distortion of the new growth. This cupping can give young leaves a canoe- or taco-like shape. Russet mites are the most difficult to spot, with early symptoms most closely resembling the general chlorosis similar to a nutritional deficiency. Russet and broad mites cannot be seen with the naked eye and require 20x or greater magnification.

 Application details of Suffoil-X, from BioWorks:
1.25 fl oz per gal or 1 gal per 100 gal as a foliar spray. Full coverage is essential, acts as a suffocant. Apply when rapid drying will occur and when air temperatures are below 85° F to avoid phytotoxicity. Flower caution on label. 4 hr REI. MOA UNE. OMRI listed.

Caterpillar Control in Hemp and other crops

 Viruses - everyone’s heard more than they want to know about them. Many growers know someone who has dealt with one. But what if we changed the narrative? Not all viruses are harmful.  Gemstar LC is one such example. Gemstar LC is a baculovirus insecticide that contains a naturally occurring virus that infects and kills larvae of the Helicoverpa or Heliothis spp. With this very host-specific virus, beneficial insects, fish, wildlife, livestock, and humans are left untouched while pest species are devastated.

 Originally developed for use on sweet corn, the label has recently expanded to include hemp. Hemp crops can be severely damaged by the following, virus-vulnerable pests:

• Corn Earworm
• Tomato Fruitworm
• Cotton Bollworm
• Tobacco Budworm

 While federally registered for hemp, Gemstar LC is also on many of the state lists approved for use on cannabis.  Gemstar LC can be used late in the crop cycle without residues remaining in the harvested bud.  Gemstar LC can be used the day of bud harvest with just a 4-hour REI.

 Gemstar LC must be eaten by the larvae to be effective. Gemstar LC is most effective against first or second instar larvae, so a scouting program to detect pests very early in the season is recommended. Frequent application at lower rates is more effective than infrequent applications at higher rates, to give larva ample opportunity to consume the virus. Other pesticide products, such as BTs, have a similar mode of action. Combining these products will not increase efficacy, so choosing just one is best.

 Death is not immediate - it may take several days to see results.  Once dead, the insect releases millions of virus particles to potentially infect other insects that come in contact with the cadaver. In summary, this good virus reduces the need for harsh insecticides during a critical part of the crop cycle.

 Some keys to effective results with Gemstar LC

• Label rates are 4-10 oz; use the higher rate for higher insect pressure.

• Gemstar is sensitive to direct sunlight; spraying is best done at times where the sunlight is not as direct like late afternoons, evenings or cloudy days.
• Complete spray coverage is important; typical spray volumes range 20-100 gallons per acre with more required for larger plants.
• Do not use silicone-based spreaders
• Use of methylated seed oils, latex, humic acid even powdered milk have been shown to enhance effectiveness

To learn more about Gemstar LC reach out to your Griffin sales rep or the GGSPro team to find out how a beneficial virus can enhance your insecticide program.

Two Spotted Spider Mite (Tetranychus urticue)

 

Several biological control options for spider mite are available. For preventative measures, species of Amblyseius mites such as A. andersoni, A. californicus, and A. swirskii can be released with sachets that produce vast numbers of mites over a 4-5-week period. This ensures that even if there are no large populations of spider mites on the crop at the time of release, predators will consistently be introduced to prevent populations from developing and establishing. These sachets work by providing a fungal food source for a feeder mite within the sachet. The predatory mites then utilize the feeder mites as their food source. Once the population of predators in the sachet increases, they exit the sachet and begin to look for food on the crop. These predatory mites are great hunters and searchers, giving the grower confidence that spider mites will be found before they become an issue.

For curative measures, there are two options of release. Primarily, Phytoline (Phytoseiulus persimilis) mites are used as the first defense against problematic populations of spider mites. These mites are very particular and will not eat anything except spider mites. This gives the persimilis an edge when wanting to remove outstanding populations of mites, instead of being a preventative method since they cannot survive without spider mites present. These mites are best released via a bottle, blister, or vial depending on the situation. Bottles are typically used in the vegetative state of crop, while vials and blisters are used most typically in the flower state to reduce risk of carrier getting stuck in the flowers. Blisters are a great way to do this because the back of the blister is popped, and then the blister is hung on the crop. The persimilis crawl out themselves and no carrier is spread throughout the crop.

Feltiella can also be used as control measures. These midges lay their eggs in dense populations of mites, with their larvae feeding on mites. They work in conjunction with other bios and can be very effective for establishing control. They are released by trays that are left in the crop, allowing midges to fly and find the sources of food for their larvae.

Though Amblyseius mites are most typically used as preventative measures, they can also be used as a curative. As a curative release, these bios are typically introduced into the crop via bulk material, like a 1L tube or 5L bag, depending on amount needed. Sometimes, broadcast releases over the top of the crop can be a concern to growers, so there has been an increased use of release boxes. Release boxes are small boxes that hang from each plant and are filled manually with the bulk material in the tubes or bags. Once filled and hung, the mites enter the plant canopy the same way that they would from blisters, with no carrier being spread over the crop. Rates of release depend on the density of spider mite populations as well as the density of the plant canopy.

Item Number	Product
SB8042-01	Universal Release Box - Bioline
SB1201-02	P. Persimilis- 2K adult mites
SB0016-03	A. andersoni - 25K adult mites
SB0016-31	A. amdersoni - 200 mini sachets
SB0013-01	A. californicus - 2K adults
SB0013-31	A. californicus - 200 mini sachets
SB1501-01	Feltiline - 250 pupae
SB1201-09	Phytoline Blisters (5)

BioSafe Tech Tip

 As new CEA producers sprout up around the country, there have been almost as many advertising claims made about ‘pesticide-free’ facilities. While that’s comforting to think and read about, it’s important to keep in mind that nature abhors a vacuum. Especially when it comes to 6- and 8-legged pests. While modifications can be made in CEA environments to accommodate vegetables, herbs, cannabis, or flowers, the humidity, temperature, absence of natural biological controls and abundant food can attract, sustain, and explode pest populations. Even as CEA growers work diligently to prevent pests from penetrating their

carefully crafted biosecurity protocols, chances are good that at some point arthropod visitors will show up uninvited. It would be a rare facility indeed that didn’t have to manage at least one concerning pest.

Bringing in plants or cuttings is a common way that pests are introduced. For that reason, inspecting and quarantining new material is well worth the time investment. Regular and systematic scouting of your plants will ensure that you catch infestations in the earliest stages allowing you to find and manage pests before you have to bring in the big, synthetic chemistry guns.
 

Biological control agents (BCAs) are often the first line of attack. However, sometimes the cost, time, or feasibility to implement biocontrol necessitates additional control measures. Biorationals work in tandem with most BCAs and break down completely within a matter of days to ensure there are no pesticide residues on the finished product. That’s something you and your customers can feel good about.

Products such as BioSafe Systems’ BioCeres WP (the entomopathogen Beauveria bassiana), AzaGuard (full-spectrum azadirachtin), and BT NOW (lepidopteran specific Bacillus thuringiensis) have only a 4-hour re-entry interval and can be applied up to the day of harvest. In fact, successful biocontrol programs often incorporate both biorational products plus the use of compatible biocontrol agents, whether via cutting dip, fogging, spraying or drenching. Combining multiple tools to ensure all stages of the pest are managed can minimize the extent and time to mitigate an inevitable infestation.