Cannabis News

Nighttime humidity is not a problem that needs to be vented away

Published

1 month ago

December 28, 2025

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Night hours present a persistent and costly challenge for commercial greenhouse operators. When the thermal screens are closed and the ventilations are closed, the greenhouse is closed, trapping the moisture produced by the crop. This creates a high-stakes battle against condensation, disease and unnecessary energy loss. Amir Kandlik, B.Sc. Plant Science and Genetics in Agriculture and agronomist with Drygair explores the critical problem of nighttime humidity and explains the strategic shift from traditional ventilation-based control to a system built around active indoor dehumidification. “This ‘closed greenhouse’ approach improves energy efficiency and supports stronger crop health.”

Night challenge: Thermodynamic and pathological risk
“At night, plants continue to transpire even though photosynthesis has stopped. Without the drying effect of daytime conditions, the air mass in the greenhouse quickly approaches saturation,” says Amir. “Traditional methods rely on ventilation, but ventilation replaces warm, CO₂-rich air with cold outside air. This increases heating demand, destabilizes temperatures and can introduce more moisture, especially in humid weather.”

A variation of this, heating the air before it is vented, wastes energy because the air conditioner is blown out immediately. “In cold, rainy, or snowy conditions, ventilation becomes impossible and humidity increases unchecked. As relative humidity rises above 85 percent and temperatures drop, surface temperatures can drop below the dew point. Condensation then forms on leaves, fruit, and structural elements, creating conditions that promote Botrytis, powdery mildew, and powdery mildew.”

Solution: “Closed” paradigm with active dehumidification.
A more advanced strategy replaces night ventilation with active internal dehumidification, keeping the greenhouse closed. Amir explains that it starts when the unit pulls in moist air, cools it below its dew point and condenses the water vapor into liquid form. “The latent heat released by condensation is captured and recycled, heating the dry air before redistributing it throughout the cottage. Instead of losing heat to dryness, this method converts moisture into heat and creates a net positive energy cycle.”

Basic advantages of the closed night strategy
This approach improves disease prevention by maintaining a stable vapor pressure deficit and preventing dew formation. Keeping surfaces above the dew point significantly reduces disease pressure. Flower tests recorded a 98% reduction in Botrytis when relative humidity remained below 85%. Energy efficiency is also increased because the airfields remain closed and latent heat is recovered during dehumidification. Vegetable producers have reported energy savings of 50%.

“Climate uniformity is improved as constant air circulation removes microclimates, and sealed conditions store CO₂ for uptake at dawn,” says Amir. Crop quality and yield benefit from consistent transpiration and improved movement of nutrients and calcium. Basil had a 15 percent yield increase without downy mildew, and unheated tomato houses had a 25 percent higher yield per stem.

Practical settings for leaders
Adopting this strategy requires changing the operational logic, which is usually handled by a climate computer. “During the day, the vents are open and the natural ventilation manages the humidity, so the dehumidifiers are turned off. At night, when the outside temperature drops below the indoor set point, the vents and screens close, and the dehumidifier operates at an RH of about 75 to 80 percent. The priority is to maintain a dew point range of at least 2 degrees. While heating is used only for temperature stability, nighttime temperatures stay below 10 degrees Celsius. in regions with , an additional defrost coil is required for continuous operation.

Looking at the field results
Field studies show that flowers grown according to this strategy maintained lower relative humidity, achieved significant energy savings and did not require night ventilation. Basil trials showed a 15 percent increase in yield and zero downy mildew. Tomatoes and peppers have seen a 5 to 25 percent increase in yield and a 98 percent reduction in disease. Cannabis growers recorded 30 to 40 percent higher yields with about 50 percent energy savings.

Specific questions about geography and climate
In very cold climates, this view is especially good. Ventilating at minus 10 degrees Celsius creates an extreme heating load, and sealing the greenhouse and dehumidifying the interior retains heat, recovers latent heat and reduces boiler use. In hot and humid climates, night ventilation is unreliable during warm or rainy weather. Active dehumidification removes moisture in a controlled manner, and with additional Air-Water Heat Exchange, the system can heat or cool the air through an external water loop.

Supporting scientific and technical references
Research includes Elad and Shtienberg’s work on Botrytis cinerea, University of Massachusetts Extension greenhouse moisture reduction guidance, Stanghellini’s transpiration studies, and Ho and Adams’ work on water and nutrient uptake in tomatoes.

Without ventilation
“Nighttime humidity is not a problem to be banished, but an imbalance to be managed,” says Amir. “The closed greenhouse strategy treats moisture as an energy resource instead of a waste product. By keeping greenhouses closed at night and using active internal dehumidification, growers can reduce disease, improve energy efficiency, retain CO₂, stabilize the nighttime climate, and increase yield and crop quality. This is one of the most impactful changes in modern greenhouse climate management.”

Related Topics:humidity Nighttime Problem vented

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Cannabis News

New partnership to expand greenhouse drone distribution across Europe

Published

7 hours ago

February 6, 2026

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GeoCue welcomes MOST Robotics to its global distribution network. Based in Germany and serving customers throughout Germany, Austria and Switzerland, MOST Robotics will offer TrueView GO LiDAR solutions and LP360 software, from GeoCue, to surveying, construction, forestry, agricultural and industrial inspection professionals looking for a complete and reliable workflow from data capture to delivery.

Founded in 2021 by Valentin Möller and Lennart Stollberg, MOST Robotics builds on deep UAV experience since 2015, offering integrated turnkey drone and sensor solutions, supported by technical consulting and first-class customer support. Their team works closely with end users to ensure technology works in real-world conditions, from flight planning to endpoint cloud processing, a full-service company for individual solutions.

MOST Robotics is expanding its portfolio of handheld SLAM LiDAR and LP360 software to directly respond to customer needs, especially for projects where flight restrictions, dense vegetation or indoor environments make aerial collection difficult. With TrueView GO and LP360, customers can complement drone surveys with ground-based SLAM capture, process aerial LiDAR and produce high-quality photogrammetric output. This approach supports rapid and accurate classification of large data sets and the creation of highly accurate digital terrain models, helping to reduce office processing time while improving the final quality of delivery.

Valentin Möller, CEO of MOST Robotics, commented: “GeoCue makes UAV LiDAR and SLAM bridges in a way that matches how our customers work in the real world. We spend a lot of time in the field with customers, which gives us practical feedback and clear ideas on what needs to be improved. GeoCue is open to this kind of input, and we’re excited to help shape each of our customers’ missions.”

Samuel Flick, GeoCue’s European Sales Manager, added: “We are delighted to welcome MOST Robotics to the GeoCue distribution network. Their technical depth and customer-first approach make them a strong partner as we continue to grow the LiDAR market in Europe. We look forward to supporting their team as they expand access to the TrueView product line, including aerial, handheld and LiDAR 360 mobile device software.”

For more information:
MOST robotics
https://mostrobotics.com/

GeoCue
https://geocue.com/

Cannabis News

USDA-APHIS grants non-regulated status to two gene-edited hemp varieties

Published

1 day ago

February 5, 2026

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USDA’s Animal and Plant Health Inspection Service (APHIS) recently issued regulatory status review responses for two new gene-edited hemp varieties, determining that they are not subject to federal regulation under 7 CFR part 340. Developed by researchers at the University of Wisconsin-Madison, these gene-edited plants have been found to have no increased risk of plant pests compared to conventional hemp. This federal clearance marks an important milestone in easing the path from laboratory to commercial cultivation of precision-bred industrial crops.

Badger PMR (Dust Resistant) has full dust resistance, and Badger Zero (Cannabinoid Free) is cannabinoid free. The main innovation involves the creation of hemp varieties that are unable to produce THC (tetrahydrocannabinol), the psychoactive compound found in cannabis. Using CRISPR gene-editing technology to turn off specific genes responsible for THC production, the UW-Madison team has solved a major hurdle for the industry. This genetic certainty prevents crops from being “hot” — the term used when THC levels accidentally exceed the legal limit of 0.3 percent — which previously forced farmers to destroy entire fields to comply with federal law.

Beyond THC removal, researchers have also engineered varieties with higher concentrations of CBG (cannabigerol), a non-psychoactive cannabinoid valued for its potential therapeutic benefits. These advances are expected to stabilize the hemp market, providing growers with reliable, high-value and legal-compliant varieties. With the regulatory green light from the USDA, these precision-bred hemp lines are poised to revitalize the industry, providing a safer and more profitable future for farmers across the United States.

For more information:
International Service for the Acquisition of Agricultural Biotechnology Applications
Email: (email protected)
isaaa.org/default.asp

Cannabis News

Kentucky Governor Announces Medical Marijuana Gummies Are Now Available, While Pushing Lawmakers To Approve New Qualifying Conditions

Published

1 day ago

February 5, 2026

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Kentucky’s governor is urging lawmakers to give more patients legal access to medical marijuana, announcing that cannabis gummies can now be purchased at state-licensed dispensaries.

Gov. Andy Beshear (D) said Thursday that his administration has sent a letter urging legislative leadership to pass a bill that lists ALS, Parkinson’s disease, Crohn’s disease, sickle cell anemia, fibromyalgia, glaucoma, terminal illnesses and other conditions as conditions for medical cannabis.

“In most other states that have a medical marijuana program, these are conditions that are covered, and conditions that are deemed appropriate by our board of physicians and counselors,” he said. “Expanding the list could help the approximately 430,000 Kentuckians who currently lack access but face these challenges.”

The governor said state officials are “making great strides” in expanding the medical marijuana program to “increase access for those who are already eligible.”

“We currently have 510 registered professionals and over 18,500 approved cards, and those numbers continue to grow,” Beshear said, adding that regulators are making “steady progress” in accepting businesses at every step of the cannabis supply chain.

“As the supply chain expands, patients are starting to see more options online,” he said. “We can announce that gummies are on the market in Kentucky and showing progress in communities across Kentucky.”

The governor’s latest update comes about a month after he took the podium and said “not happy” with the time it’s taken to roll out the state’s medical marijuana program—but predicts that the pace of patient access will “significantly increase” in 2026.

Also last month, Beshear said two more dispensaries will open their doors “once additional product becomes available.” The The state’s first medical cannabis plant was launched in December.

The governor, who has long championed cannabis reform, he anticipated a market launch that monthwhile claiming that medical marijuana will help thousands of patients find an alternative to opioids for pain management.

He at the end of October it passed the milestone of registering 15,000 patientsbut that has grown significantly in recent weeks.

Beshear previously acknowledged that “it’s taken longer than we would have liked” to sustain the industry since he signed off on legalizing medical marijuana in 2023.

Considering this delayed implementation, he signed an executive order this year to waive renewal fees for patients who get the cards so that they are not charged again before the stores open. And another order he signed to provide protections for qualified patients who obtain medical marijuana outside of Kentucky “will remain in place.”

Beshear announced separately that in May the state launched a new online directory that allows people to see where medicinal cannabis will open next to them

He noted that the state is working to provide access to patients “as soon as possible,” which includes speeding up the licensing process. Last January, so did the governor ceremoniously issued the first medical marijuana cards in the commonwealth.

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Meanwhile, the governors sent a letter to Kentucky’s congressional delegation last yearurging them to “take decisive action to protect the constitutional rights of our law-abiding medical cannabis patients” by repealing the federal ban on possession of firearms by marijuana users.

Bipartisan Kentucky senators introduced similar legislation asked the federal representatives of the state to take corrective measuresBeshear said he agrees but would I would like to see even more significant changes at the federal level.

The federal Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) warned Kentucky residents that in 2024, if they choose to participate in the state’s medical marijuana program, they will be prohibited from buying or possessing firearms under federal law.

Health professionals have been able to Patients began to evaluate the recommendations from the beginning of last December.

While there are currently no operational dispensaries for patients, Beshear also confirmed that an executive order he signed in 2023 will be in place in the interim, protecting patients. Those with medical cannabis purchased from licensed out-of-state retailers.

In the November 2024 election, Kentucky also saw more than 100 cities and counties pass local ordinances to allow medical cannabis businesses in their jurisdictions. The governor said the election results show that “the jury is no longer out” on the issue this is clearly supported by voters across party and geographic lines.

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