Hi everybody! Welcome to this installment of “let’s talk about elements”! This post is dedicated to our tiny friends in the fertilizer world: micronutrients! There are quite a few; I don’t want to be a-BORON you (...yes I am really happy about that pun), so I decided to break the nutrients into two separate blog posts. This post is background of the micros, and part two will go into the nitty gritty details. When we say micronutrients, we are referring to the following elements:

1. Manganese (Mn)
2. Boron (B)
3. Copper (Cu)
4. Zinc (Zn)
5. Molybdenum (Mo)
6. Cobalt (Co)
7. Some say Iron (FE) is a micronutrient. I classify it as a secondary nutrient.

Apologies in advance for all the puns related to the elements.

It’s quite amazing the number of accommodations we must make as hydro cannabis farmers. If you read my post on types of water sources, I mentioned that soil-based growing has a little bit more room for error (the soil is a “buffer” of sorts). As you can tell by the name of these nutrients, micronutrients do not need to be kept in high concentrations (often kept in the ranges of parts per million, or ppm). In fact, many of these nutrients in high quantities would be toxic. It’s just like cheeseburgers… small quantities and they’re great; too many and your doctor is going to yell at you. Anyway, usually soil typically has micronutrients already present and would not require fortification. Obviously, if you depleted the soil nutrients, you would need to supplements to get your micros.

Obviously, without soil in a hydroponic garden, you are robbed of these essential micronutrients. Thus, it is essential to make sure your plant is getting the supplemental micronutrients it needs.

I wish it were that simple. To add more complexity, not all micronutrient sources are the same. The reason why has to do with nutrient mobility: micros tend to be very immobile nutrients. This is a good thing, because if all the heavy metals in the world were able to move quickly through the soil, we would be in trouble.

The easiest way to explain this is via the periodic table: most of the micronutrients are called transition metals (in the middle section of the periodic table). These metals have super high affinities for the charged particles in soil (or in your case, the anions that are present in your reservoir or at the root zone such as phosphates, sulfates, etc.). So instead of going into the plant, they would interact with these things, and not be taken up by the plant. The issues I’m describing can be similar to “nutrient lockout” you see with calcium or phosphorous; but at super small levels you may not even see it happening!

I set up the above title to hopefully make you say, “chelates” wrong (if you said “chillates”…got ya!). Chelates (pronounced key-lates) are a special way to describe these micro metals. Instead of using an iron source like iron (III) sulfate (which would likely get stuck in your reservoir and not be absorbed by the plant), iron comes in “chelated” form: Fe-EDTA, Fe-DTPA, Fe-EDHHA, etc. Chelated metals are much easier for the plant to be able to take up in a usable form (Wallace, A. et al. Soil Science 1957, 84, 27–42). An entire separate post will be devoted to this, but just know that when you look at Elite Base Nutrient A, all those “EDTA”-based nutrients are essentially the security escorts for the micros to get into the plants! Side note: not all transition metals require chelation. So, let’s get into it now!

Much of the world considers iron a micronutrient – as a scientist, I actually lump it into the “secondary macros” category, because its deficiencies are similar to what we see in secondary nutrient deficiencies. The take home message about iron (discussed in detail in a future post): Fe-EDTA = chelated iron = good for your plants in small quantities for most water systems. Iron chlorosis is the yellowing of the leaves with still green veins; your plant needs more iron if this happens!

That’s all for this post, stay tuned for part 2 of the microtalk!

Resources:

Want to get in touch with Elite Garden Wholesale? They can be reached via the following methods:

1. Website: https://www.elitegardenwholesale.com/
2. Email: info@elitegardenwholesale.com

Dehumidifiers are essential to healthy yields, because they help maintain optimal moisture levels in grow rooms. They can also solve the drought-induced water scarcity so many growers face: Dehumidifiers can provide you with a source of clean, readily accessible water even during drought.

A dehumidifier is basically a refrigeration system. It has two copper tubing coils; each coil looks similar to an automotive radiator. One of the coils is hot, and the other is cold.

The system works by pulling heat from the cold coil and “exhausting” it through the hot coil. A fan blows air through the system, which removes water from the air and heat from the hot coil. The water condensate forms on the cold coil, like condensate will form on a glass of ice water during a hot day.
The condensate then runs off the cold coil and is collected into a reservoir.

Even without a drought, it’s preferable to use the perfectly good water that dehumidifiers produce rather than “dump” it – and it can actually be better than reverse osmosis water. Why? Condensate water from dehumidifiers is naturally clean and free of contaminants, while reverse osmosis machines must necessarily waste 1 to 3 gallons of water to produce a single gallon of clean water. Every gallon of dehumidifier condensate saves 2-4 gallons of water drawn out of the tap.

Yes. The cold condensate coil is enclosed within the dehumidifier. Because dehumidifier coils are not soldered with lead as is common in other applications, there’s no chance of lead contamination, either. Instead, copper coils are brazed.

If you would like to read part one, click here.

Resources:

Want to get in touch with Quest Hydro? They can be reached via the following methods:

1. Website: https://questhydro.com/
2. Email: info@questhydro.com
3. Phone: 877-420-1330

Editor’s Note: There are several research sources that have discussed the phenomenon of phototaxis. Before buying or installing equipment, make sure to do your research on what insect pests you’re hoping to repel or attract. Growers Network always recommends conducting your own experiments before taking anyone’s word as truth!

I had an interesting experience early in my career at a warehouse in Texas. The facilities manager decided to switch from HPS lighting to metal halides to take advantage of their color rendering index. Within months, the manager noticed that there was a spider problem.

When the manager called me, I realized that the yellow lights had previously been keeping the spiders out. After some painful modifications, the manager switched back to the HPS lights, and, according to what he told me, within minutes spiders were marching down the aisles of the warehouse and out the doors. Within a few days, all the spiders had vacated the building.

This is when Metaphase began developing its own insect-deterrent light.

Editor’s Note: Lights may attract or repel insects depending on the species. For example, it is well-known that moths are attracted to blue light, or that cockroaches are repelled by virtually any light. Every light may have a tradeoff as to what insects it attracts and repels.

A Midwestern university tested our experimental insect deterrent light. They found that it was most effective on aphids, as they would evacuate a growth chamber in which the light had been placed. The chamber was completely bug-free within the week. I followed up the university tests with experiments in cannabis greenhouses located in Colorado and Maine. Aphids consistently moved away from areas illuminated by the lights. This was observed by Tuinier Brothers Flowers when they positioned their hanging baskets, infested with aphids, between the lights.

The same university also was the first to notice that our lights deterred spider mites. Mites would not cross from infested plants to nearby healthy plants that were illuminated by the insect deterrent light. It was as if the light acted as a barrier that the spider mites would not cross. We took this knowledge and field tested the lights in greenhouses of Colorado and Maine that had already had an infestation of spider mites. The lights were positioned on the floor beneath the canopy of the cannabis. The mites hid on the top of the leaves to get away from the light and laid their eggs on non-illuminated plants.

Again, the same university also reported that the light was keeping thrips out of illuminated grain. This grain was even placed inches away from infested plants. The thrips simply stayed away from the light.

Brighterside Vertical Farms in Colorado reported that their customers had been experiencing outbreaks of russet mites. They wanted to try the insect lights to see if they would have deter mites that were infesting some cannabis clones. We saw two results:

1. The russet mites ran away much faster than expected.
2. The clones grew much healthier stems and thicker and longer roots. Whether this was a side effect or direct cause is inconclusive.

Editor’s Note: Lights may attract or repel insects depending on the species. For example, it is well-known that moths are attracted to blue light, or that cockroaches are repelled by virtually any light. Every light may have a tradeoff in what insects it attracts and repels.

A grower I worked with had an infestation of Japanese Beetles. Much to his surprise, the beetles were flying into the light that he was using to repel mites. The beetles would fly into the light and then fall to the floor of his greenhouse. In a clever move, he placed a bucket of water where the beetles were falling. After that, his concern became changing a bucket, not managing an infestation.

Consejo Superior de Investigaciones Científicas, a Spanish agricultural research center, found that the insect light was very effective on whiteflies, but not in the way they were expecting. The research personnel thought that the whiteflies would be repelled by the light, but to their surprise, the whiteflies flew toward the lights. The researchers attached some double-sided film tape over the lenses of the lights, and the whiteflies flew into the tape. After applying some clean tape, the researchers were able to capture and remove each one of a hundred whiteflies.

A US government research facility was looking for a solution to fight psyllids (jumping plant lice). The researchers expected that the psyllids would be repelled from the light, but instead the psyllids were attracted to it. The researchers set up a test area which included a window to the outside (daylight) and a translucent panel located 4’-6’ away illuminated with the insect light. A plant was placed about 6 inches from each panel. The 200 psyllids, which were reared at this facility, were released in the middle of the test area. More than 60% of the psyllids flew toward the insect light while the others ventured towards the daylight. The psyllids that headed for the daylight landed on the plant, while the psyllids that headed toward the insect light flew right past the plant and landed on the illuminated panel.

We’ve scheduled our insect deterrent light for additional tests throughout the world. The light was recently made available for commercial use, and can be found on our website.

Resources:

Want to get in touch with Gary Sigman? They can be reached via the following methods:

1. Website: https://www.metaphase-tech.com/
2. Email: G.sigman@metaphase-tech.com

Last month our topic was humidity. This time we’ll discuss ventilation, a traditional, if inefficient, method to reduce humidity.

Growers in closed facilities face complicated challenges, one of the more complicated challenges being humidity.

Humidity inside a growing facility is generally caused by transpiration from plants. If humidity gets too high, drops of water form on the plants, causing humidity-related diseases such as Downy mildew, Botrytis, Alternaria, Powdery Mildew, Erwinia, Phytophora, or Clavibacter. Reducing the humidity inside growing facilities can prevent diseases and reduce the need for pesticides.

A traditional solution to treat humidity is ventilation. Ventilation is a relatively low-tech solution to humidity issues.

There are two main types of ventilation:

1. “Natural” ventilation is the opening and closing of a growing facility’s doors and windows to replace the humid air inside with external (hopefully) dry air.
2. “Forced” ventilation uses fans to replace the humid air inside with external (hopefully) dry air.

Plants transpire all day. They transpire around 88% of the water they absorb during the day. When the weather outside is dry, ventilation can be a very effective method to reducing humidity. Moreover, during daytime (when it’s warmer) ventilation can also lower the heat inside.

There are three main problems growers face during nights or on cloudy, rainy, or cold days:

1. Loss of energy. Opening a growing facility leads to loss of warm air, especially in colder conditions. A loss of heat energy often leads growers to use more energy in order to reheat the facility. In fact, according to experts, ventilation can be calculated as an average energy loss of around 75kw.
2. Moreover, when the air outside is just as humid, or more humid than the air inside the growing facility (on rainy days, cloudy days) ventilation becomes ineffective.
3. No uniformity. Taking in external air creates microclimates of temperature and humidity inside the growing facility. This difference in climate conditions affects the growing process and the development of the plant, ultimately leading to an inconsistent yield.

Editor’s Note: Colder, humid air can be brought in as well. Because the air is colder, it contains less water, but can have the same RH. If the cold, humid air is heated up, it lowers in RH. This is relatively inefficient method of dehumidification, but is a ventilation method of dehumidification.

These days, many growers are acknowledging the importance of dehumidifiers. DryGair products, for example reduce the need for ventilation during the night or on cloudy/rainy days. The goal is humidity reduction without ventilation. This can save upwards of 50% of the energy invested in the operation of the facility.

Please use our contact information below to send us questions!

Resources:

1. Want to get in touch with DryGair? They can be reached via the following methods:
   1. Website: https://www.drygair.com
   2. Phone: +972-9-7730980
   3. Email: info@drygair.com