CEA Greenhouse Tips

Why Are In Vivo Nematodes Beneficial?

Nematodes, specifically Steinernema feltiae, have an intense action against fungus gnat larvae and thrips pupae found in crop media. A popular choice among greenhouse growers of all kinds, this microscopic biological control agent (BCA) has wormed its way into many effective integrated pest management (IPM) programs. Currently, a global SF nematode shortage is affecting many suppliers, leading growers to explore other product options to fill this void.

Nematodes Alternative: Sanitation

Sanitizing surfaces surrounding the growing area can go a long way to controlling fungus gnat and thrips issues. Proper sanitation practices help prevent the spread of algae, which serves as a potential food source and breeding space for several pests such as fungus gnats and shore flies. Products such as ZeroTol 2.0, SaniDate 5.0, and PERPose Plus are often approved for hard surface sanitation and may be used at lower concentrations to reduce the occurrence of algae on soil surfaces or in irrigation piping and tubing.  

Nematodes Alternative BCAs

Though no other BCA is quite as effective as nematodes against fungus gnat larvae and thrips pupae, some preventative pressure can be maintained through strategic applications of different species. Atheta coriaria and Hypoaspis miles, two primarily soil-dwelling BCAs, prey on larvae and pupae at the soil level. These two insects may survive for long periods in the crop media when maintaining even moisture and avoiding incompatible pesticide drenches. Though unable to handle severe infestations on their own, these BCAs may be incorporated into a preventative regimen to keep thrips and fungus gnat pressures low. 

In Vivo Nematodes

Several suppliers offer In Vivo Nematode products. With classic nematode products, nematodes are grown using a fermentation process that occurs in a nutrient solution. In Vivo nematode products are produced following the natural life cycle in live hosts. While both production methods produce effective nematodes, the In Vivo nematodes generally release a more potent dose of the pest-killing bacteria upon infection. It is not uncommon for growers to see slightly faster and higher efficacy with In Vivo nematodes. 

Though global shortages are not currently impacting In Vivo nematode products, this type of production is more labor and time intensive. In Vivo, the application rate for products is lower and would be an appropriate knock-down treatment before beginning a preventative regimen combining adequate sanitation and alternative BCAs. Please reach out to your Griffin sales rep or the GGSPro technical team for crop-appropriate rates and usage tips. 

Products

Product Name		Item Number
Zerotol 2.0 5Gal		71-35481
Sanidate 5.0 5Gal		71-35151
PERpose Plus 5Gal		71-2690
DALOTIAforce 1k beetles		30DC1N
Staphyline 500 beetles		SB0061-01
STRATIOforce 25k mites		30SS25
Hypoline 25K mites		SB0091-04
Sentry 25M nematodes		70-7025
In Vivo NemaShield, 24M nematodes		NEW

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Root Aphid Misconceptions

Many growers turn to biological control agents (BCAs) to effectively control foliar aphids; why should root aphids be any different? The difference lies in location, location, location! Root aphids tend to infest the entire container profile. Wherever plant roots are found, root aphids will follow. Root aphids hide out in any available crevice, providing a seemingly endless source of re-infestation. These deep colonies are the sticking point for most BCAs. Nevertheless, many growers have heard rumors of success with various BCAs. This tech tip will examine a few such BCA/root aphid relationships.

Stratiolaelaps scimitus (Hypoaspis) mites 

Hypoaspis miles, also known as Stratiolaelaps scimitus, is a soil-dwelling predatory mite with the ability to survive for long periods of time in the crop media. Their primary prey consists of fungus gnats, shore flies, and thrips pupae. This BCA reproduces in high numbers, quickly establishing populations. Hypoaspis mites have been observed feeding on root aphids, but their limiting factor is physical access. Hypoaspis mites are only active in the top and bottom inch of container media. Deeper aphid colonies will remain untouched, providing new waves of pests as these colonies continue to feed on plant roots and reproduce. 

Nematodes 

Nematodes for use as biological controls have been established as an easy and effective tool for growers to use. From fungus gnats and shore flies to thrips pupae, their efficacy is well understood. Nematodes have the advantage of being able to be drenched into media, though typical nematode applications only target the top two inches of soil. Nematologists confirm that certain species of beneficial nematodes, specifically Heterorhabditis bacteriophora, have the capability to harass and infect root aphids, but their capacity to kill is far outpaced by the root aphids’ speed of reproduction. 

Dalotia/Atheta/Rove beetle 

Rove beetles are media-dwelling insects that help growers manage shore flies, fungus gnats, thrips pupae, springtails, and other soil-dwelling pests. They are aggressive feeders, spending most of their time at media-level but adults may fly around at night in search of prey. Being a generalist predator, they may indeed prey upon root aphids that they encounter, but their contact is limited. Dalotia beetles dwell primarily in the top ½ inch of soil or media, again leaving deeper hidden colonies of aphids untouched. 

So, what DOES work?

Our current recommendations fall back on full-pot-volume drenches of biopesticides and insect growth regulators. Specifically, the combination of B. bassiana fungal spores with an azadirachtin product has shown some level of control in production environments. Drenches target root aphids while sprays control foliar aphids and fliers. A tank mix and weekly spray/drench of these products can go a long way toward achieving or maintaining control of both root and foliar aphid species. For more information contact your local Griffin rep or the GGSPro team.

Product Name		Item Number
BotaniGard WP		70-12521
BotaniGard ES		70-12511
BioCeres		70-1245
Velifer		70-9540
AzaGuard		70-1225
Azatin O		70-12301
Molt-X		70-2410
Aza-Direct		70-1222

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pH Correction for Irrigation Water

 Why? When? How?

Most growers know that correcting pH is important, but they don't always know why. When we correct the pH in irrigation water, we are actually adjusting the irrigation water alkalinity, but why are we doing that?

Figure 1

To understand, we need to define pH. In simple terms, the pH of a solution relates to the concentration of hydrogen cations (H+). The pH scale goes from 1 to 14, where the lower the pH (high H+ concentration), the more acidic; the higher the pH (low concentration of H+), the more basic.  

Why is irrigation water pH important in CEA? The nutrient availability for plants is affected by pH (Fig 1). Whereas Iron (Fe), Manganese (Mn), Boron (B), Zinc (Zn), and Copper (Cu) are more available at low pH values, Calcium (Ca) and Magnesium (Mg) are more available at higher pH values. At very low pH, however, the increase in Fe, Mn, and Al (Aluminum) can become toxic. Therefore, between 5.5 and 6.2, most micronutrients are available at proper levels.

Why do we correct irrigation water alkalinity? The concept “alkalinity,” is a measure of the resistance of a water solution to change its pH. When acid is added to the irrigation water, the H+ of the acid first react with the carbonates and bicarbonates on the water forming CO2 and water. Initially, pH decreases slowly. When no more alkalinity is left, the pH will drop abruptly. 

We measure alkalinity in ppm.  Even though it’s closely related to pH, two different water samples could have similar pH values but different levels of alkalinity. It’s going to take much more acid to lower the water sample's pH with more alkalinity than the one with less. 

Carbonates and bicarbonates brought by the irrigation water will react with H+ in the growing media and increase its pH, lowering the micronutrient availability.  Plants will suffer micronutrient deficiencies. But completely removing the alkalinity is not necessarily good. Most fertilizers are acidifying in nature; if our irrigation water does not have any alkalinity, the acidifying fertilizer can lower the growing media pH to toxic levels. This case can be observed with RO water, where all alkalinity was removed, and potassium bicarbonate is needed to increase the alkalinity to a desirable value of 60-70 ppm.

We correct pH (mostly lower it) to correct alkalinity and optimize micronutrient availability. In some cases, we start with water that has no alkalinity. Then we need to adjust the pH up due to the natural acidifying quality of most fertilizer formulas.

Product Name		Item Number
Dosatron 14 GPM Injector with Bypass		33-2417
Dosatron Etatron eOne Kit Low MicroDoser Kit		218-1820
Dosatron Etatron eOne Kit HI MicroDoser Kit		218-1821
Dosatron Etatron Ultrasonic Lo MicroDoser Cabinet		218-1822
Dosatron Etatron Ultrasonic Hi MicroDoser Cabinet		218-1829
Dosatron D132 Mega-Flo Injector		33-2428
Dosatron D400 Mega-Flo Injector		33-2429
Sulfuric Acid 93% Tech Grade 1GAL		75-5030
Sulfuric Acid 93% Tech Grade 15GAL		75-5034
Phosphoric Acid 75% Tech Grade 4-1GAL/CS		57-100239
JACKS CITRIC ACID 25 LB		J74321
JACKS POTASSIUM BICARBONATE 1 LB		91-2190
JACKS POTASSIUM BICARBONATE 25 LB		91-2191
General Hydroponics pH Up 1 gal		HGC722095
General Hydroponics pH Down 1 gal		HGC722125
Dosatron Meter pH/Temp Hydro		33-2710
Dosatron Meter pH/Temp Pro		33-2715
Dosatron Replacement Sensor pH		33-2725
Dosatron Storage Solution pH Electrode 600		33-2740

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Controlling Pest Caterpillar in The Field

Trichogramma wasp parasitizing lepidoptera egg.

Lepidoptera species are one of the top pests of hemp and cannabis production and may appear anytime from early spring well into fall.

Types of Lepidoptera

Species such as Eurasian Hemp Borer, European Corn Borer, Corn Earworm, and many others cause significant damage when left unchecked.

Types of Damage

Damage from these pests commonly takes two forms: stem boring or leaf chewing. Stem boring refers to when the insect eats its way into the plant, while leaf chewing refers to defoliation.

Understanding and controlling the lifecycles of these pests is key to season-long damage protection. Lepidoptera typically go through four main stages: egg, larval, pupal, and adult stage. The larval stage is represented by caterpillars. The pupal is the cocoon stage when they are often dormant. The adult stages appear as moths, flies, or butterflies. Different control strategies target different life stages, so timing control activities is very important.

Cultural management can help growers handle the larval and adult life-stages and generally follows these two focuses.  

·       Environmental Cleanup - Through the vigilant season-long reduction of weeds and plant debris, growers remove the preferred habitat, potential food sources, or breeding areas. This is effective at combating all four stages

·       Traps - The use of UV light traps and pheromone lures helps manage the population of adult moths when properly positioned and employed.

Spray treatments can be added to cultural control strategies and are highly effective for the larval stage, however they may not be approved for all locations or all crops.

Biological Control Agent (BCA) Options

Various species of Trichogramma wasps target the egg stage of many Lepidoptera. These biological control agents (BCAs) can be released either in a loose bulk carrier throughout the crop or as eggs on cards that can be hung on plants. As the Trichogramma eggs hatch, the wasps emerge and hunt down Lepidoptera eggs to parasitize. Once eggs have been attacked by wasps, the pest life cycle halts. Weekly applications should begin in early June to catch the first generation of eggs and continue throughout production through August. 

Different species of Trichogramma prey on different Lepidoptera species. Contact your GGSPro BCA specialist for help determining which species is most appropriate for your operation.

Griffin Lepidoptera Control Products

Product Name	Supplier	Species	Size	Item Number
Tricholine	Bioline	T. Brassicae	20K or 10K pupae	SB0451-04, SB0451-01
TRICHOforce B	Beneficial Insectary	T. Brassicae	10K pupae	30TBH
Trichogramma	Beneficial Insectary	Mixed	100k pupae	30TBH

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Surface Sanitation with SaniDate 5.0

Facility infestations can quickly go from bad to worse in the absence of proper sanitation practices. Cross contamination from host sites can affect crop health and reduce yields.
A thorough sanitation program significantly impedes the spread of bacteria and disease by removing favorable conditions for their development and addressing critical control points.

 

Critical control points are potential areas of infection (and re-infection) within growing and
non-crop areas such as under benches, entryways and cooling pads. Identifying these points is be integral for developing your facility’s program. Keep in mind sanitation is not just an ‘end of the season’ activity, it should be practiced throughout the production cycle. Standardizing practices such as spraying/foaming racks, empty benches, walkways and sanitizing containers, trays and equipment will maintain a clean environment.

 

Hard surfaces with algae and organic matter create a favorable environment pathogens and pests thrive in, including fungus gnats and shore flies. These pests can transmit contamination and infection throughout the crop. A general cleaning step is ideal to remove organic and mineral deposits, allowing sanitizer to have better contact on the targeted area and improving efficacy. Once areas have been cleaned, utilizing a sanitizer with no-rinse step, like SaniDate® 5.0, will ensure optimal productivity.

 

SaniDate 5.0 kills pathogens on contact, does not require a post-rinse and leaves no harmful residue. Its versatility of applications and use sites make it the ideal sanitation/disinfection tool to address many, if not all, critical control points in your facility.

 

Sanitation may be a chore, but it is important for preventing many unforeseen incidents which can deprive crops of optimal health. Choose the best methods and tools that work for your facility, but always remember – an ounce of prevention is worth a pound of cure.

Preventing Damping Off in Microgreens Production

Tipburn in Hydroponic Lettuce

Figure 1. Tipburn on young lettuce leaves

Product Name		Item Number
Jack's Nutirents 12-4-16 RO		33-12416
Jack's Nutirents 15-5-20 Tap		33-15520
Jack's Nutirents 5-12-26 FeED Part A		33-51226
Jack's Nutirents 15-0-0 Boost Cal Nit Part B		33-79080

Using Sticky Cards for Insect Monitoring

Product		Item Number
2-color blue/yellow sticky cards, 4"x5"; 10 per pack		74-3668
Yellow moisture resistant monitoring cards, 3"x5"; 50 per pack		74-36705
Trapline T Yellow Roller trap 6"x328'		SB8051-05
Sticky yellow trap roll 12"x300'		74-12300
Sticky yellow trap roll 6"x1500'		74-61500
Sticky blue trap roll 6"x1500'		74-61500B

Controlling Water Flow

Written by:  Kurt Becker, Dramm Corporation 

You may have heard that the most important person on a cultivation team is the person with the hose in their hand. Proper irrigation can make or break a crop. One challenge is to ensure that proper flow and pressure to address different needs. This is complicated by the fact that crop needs change dramatically over a short period of time. How do you help your team meet these changing needs? You give them the right watering tools! 

Dramm produces a full assortment of professional watering tools, including water breakers. These specialized nozzles break the water into smaller droplets and streams, simulating rain, which softens impact on plants and media while absorbing and providing needed oxygen to the roots. Different water breakers tailor the delivery pattern, flow and volume for specific containers, media and plant stages. In addition to the essential, high-flow 400 series, Dramm manufactures innovative, specialized water breakers to meet all irrigation needs. 

The 1000PL Series. 

Starting with the original Redhead, the 1000PL uses 1000 smaller holes in a stainless steel disk. This allows for a softer pattern for younger plants along with the ability to throttle the flow while still keeping a pattern. Now, the 1000PLs are available in Narrow, Medium and Wide versions offering different amounts of water per square inch of coverage. 

750PL 

The 750PL reduces the flow even further. Using the same size hole as the 1000PL, but using fewer holes, the 750PL applies less water. This allows for lighter watering when required. The 750PL throws a wide pattern for less water per square inch of coverage.

Fan Nozzle 

Most fan nozzles are consumer tools and have uneven patterns. Dramm’s Commercial Fan Nozzle was developed to offer a precise, rectangular pattern that allows for medium to very low flow while still producing even streams. 

350PL Screen-Aire 

The 350 lands at the opposite end of the spectrum, delivering a very high flow rate with a soft, aerated pattern. Water exits the nozzle like a kitchen faucet, a single stream full of air bubbles. This allows for a lot of water without disturbing soil or top-dressed fertilizers. Great for quick watering of containers. The 350 is also perfect for rewetting dry media, as the bubbles hold the water on the surface of the media longer. 

Valves 

Remember to match the valve to the nozzle to allow precise control of flow rate. Valve operation is important to note. Does the watering require on-off operation or is it turn on and go? The OneTouch and OneTouch HighFlow offer easy control of the flow. Other valves, like the 300 Brass Shut-Off are high flow, quarter turn valves for quick watering.

	Description	Item Number
	Dramm 400AL 400 Water Breaker (alum, full)	80170002
	Dramm 400PL Water Breaker (blue, full, w/ring)	33-6101
	Dramm 170 PL Plastic water breaker	41-600101
	Dramm 350PL ScreenAire Water Breaker	33-350PLC
	Dramm 750PL Lemonhead Water Breaker (low)	33-5234
	Dramm 1000PL RedHead Water Breaker (medium)	33-5233
	Dramm 1000PL Orange Water Breaker (wide)	33-5237
	Dramm 1000PL Green Water Breaker (narrow)	33-5236
	Dramm 79001 Commercial Fan Nozzle	33-2079
	Dramm 510 brass seedling nozzle	33-5235
	Dramm Fogg-It nozzle fine 610 F	33-610F
	Dramm 610SF 1/2gpm Fogg-It Hose Nozzle (SF)	33-5327
	Dramm #300C Brass Shut Off Valve Heavy Duty	41-400300
	Dramm 74C Wide Body Shut Off Valve, Plastic	33-51051
	Dramm QAV Shut Off Valve	44-5607
	Dramm One Touch Valve Handle, Low Flow	33-14700
	Dramm OneTouch Valve Handle, High Flow	33-5365

Punch Out Powdery Mildew On Cannabis

Powdery mildew (PM) is made up of many fungal pathogen species that attack and thrive off healthy, living plant tissue. Golovinomyces sp. (aka Erysiphe sp.) is the most common PM species that growers find on cannabis today. We recognize PM as producing a distinctive white sporulation on the foliage that looks like powdered sugar. Without proper management through chemical and cultural practices, this pathogen can quickly spread throughout your operation and decrease crop quality.

Powdery mildew forms white spores on the surface of the foliage.

Conditions ideal for PM proliferation include moderate temperatures, dry leaf surfaces, and high humidity. Unfortunately, the optimal temperatures for PM go hand-in-hand with the ideal temperatures for cannabis production and keeping a dry leaf surface is needed to prevent other diseases such as Botrytis from developing. Thus, growers should prioritize the management of their relative humidity levels to prevent PM. A constant humidity level of 55-60% in the canopy (65-75% if using predatory mites) is preferable to excessively high humidity (>85%). Growers can maintain adequate humidity within the plant canopy with appropriate HVAC equipment in conjunction with horizontal airflow fans (HAF) or vertical airflow fans (VAF).

Powdery mildew should not be mistaken for trichome production

As for all diseases, sanitation is key to prevention, and it is important to sanitize your production
areas between crops. Following physical removal of debris, the first step is to clean all hard surfaces using a cleaning product such as Strip-It (for greenhouses) or Horti-Klor (for warehouses)*. Once surfaces have been cleaned, use a sanitizing agent such as KleenGrow (rinse direct crop contact surfaces with potable water), ZeroTol 2.0 or SaniDate 5.0 for disinfection purposes*. It is critical to ensure that all cuttings and clones coming into a new production area are free of disease. Immediately remove any infected foliage and dispose of it properly. Replace gloves and other protective equipment after handling infected material. Work in infected areas late in the day and avoid staff moving back into clean areas from infected areas.

EPA registered and 25(b) products need to be approved for use on cannabis by the regulatory agency in the state in which the product would be used. When using biofungicides, best practices call for application of ZeroTol 2.0 before Cease or Triathlon BA to destroy surface spores of the pathogen on contact while the biofungicide protects uninfected tissue. Contact your Griffin sales person or GGSPro for product rates and application intervals.

Product Name		Item Number
25(b) Products
Procidic 2		71-2742
EPA Registered Products
Cease		71-13301
Companion		71-1375
Horti-Klor		74-2105
KleenGrow		74-21101
MilStop		71-2879B
Regalia CG		70-2841
SaniDate 5.0		71-35001
Sil-Matrix		71-2940
Strip-It Pro		74-2125
Triathlon BA		71-3040
ZeroTol 2.0		71-35501

*Check state approval status for these products.

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Getting More From Your Cleaners and Sanitizers With Foam

All food and medicinal crop growers take great care to keep their production spaces clean. Often, this process involves a full sanitation protocol for the production space at the end of a crop cycle to reduce the risk of carryover pests and pathogens. The complete process involves four steps: Physical cleaning (remove the debris), chemical cleaning, rinsing with clear water and sanitizing.

It’s important to include the physical and chemical cleaning steps in the process prior to sanitizing. Favorite sanitizers, including ZeroTol 2.0, SaniDate 5.0 and Kleengrow, treat the surfaces they contact. If the surface is dirty, the sanitizers will treat the debris, but not penetrate to the surface below. If the sanitizer can’t contact the surface, the surface can’t get clean!

We can all increase the efficacy of our cleaners and sanitizers by utilizing the power of foam. Foaming makes the application more effective by increasing coverage and contact time. Foams also make it a lot easier to see where treatments have been applied.

Griffin offers two great foamers from Dramm to get this job done. With both small and large volume options, growers can have the right tools for all needs, from large greenhouses spaces to smaller warehouse production rooms. The Foam8L is a 5 liter compression foamer that is highly portable and great for small spaces. Expect to treat 400-500 sq ft from one full tank. For larger spaces, turn to the FM20-30 foamer. This cart unit has a 20 gallon tank, a 30 foot hose and runs on compressed air*. Both products are compatible with popular cleaners and sanitizers.

 Ask your Griffin sales person for a bulletin outlining GGSPro’s recommendations for hard surface sanitation for food and medicinal crops. Your sales person can help you choose the right cleaner and sanitizer for your situation and will let you know if you need to add a foaming agent to the tank

*Compressed air source required for the FM20-30 Foamer

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Boosting Root Development in Cannabis Crops

Essential Plus 1-0-1

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Hemp Russet Mites: Scouting and Control Tips

Hemp Russet Mite (HRM) is an eriophyid mite that can severely damage flowers and decrease THC and CBD in cannabis production. Eriophyid mites are small, cigar-shaped pests; they’re capable of reproducing profusely. They infest many horticultural crops.


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