New book review: Handbook of Cannabis Production in Controlled Environments

I just read a newly released academic journal sourced and written book from CRC Press titled, Handbook of Cannabis Production in Controlled Environments. The ebook cost me ~$58; the paperback and hardcover won’t be released for another month.

Each chapters’ authors have solid academic backgrounds, including Dr. Michael Stasiak, P.h.D (Manager and Technical Operations and Senior Research Associate at UofG’s Controlled Environment Systems Research Facility), Dr. Deron Caplan (PhD in Cannabis Horticulture from UofG), Dr. Ernest Small, P.h.D (Principal Research Scientist at the Eastern Cereal and Oilseed Research Centre), and University of Guelph, School of Environmental Sciences Profs. Youbin Zheng (P.h.D. in Plant physiology and Biochemistry) and Mike Dixon P.h.D. (Director of the Controlled Environment Systems Research Facility).

It’s a decent book, and while there’s nothing groundbreaking or new to me, it includes some helpful information, yet, I disagree with some claims in the book. For example, the claim that leaf temp is generally less than air temp (without noting caveats regarding air velocity and PPFD) and the recommendation to clip leaf tips when cloning. Clipping leaf tips is almost always a bad practice. It will increase cloning duration while reducing photosynthetic rate, leaf tissue nutrient concentrations, root growth, and cloning success rate. Don’t be a dip; just don’t clip! (j/k :wink:) Clipping leaf tips is only helpful when over-packing a cloning tray to prevent fungal diseases from constantly wet leaves.

While the book is an excellent addition to any cannabis library, I think it would be more helpful to people who, unlike me, do something else with their lives than read published research studies.

Out of 5 thumbs up, I give it :+1: :+1: :+1: :+1:



Here’s a couple of nice sections from chaper 2, Growing Facilities and Environmental Control:

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Fwiw I have always clipped clone leaves and never had a problem. I do like taking up less space. My clones are a lot smaller than what I often see on here.

Environment varies so much that there are few rules that hold up everywhere all the time. It’s like the discussion of domes over clones. People out west who live in an arid environment swear by them. But if you live in the Midwest or south, we have plenty of humidity to go around. I’ve never used a dome, either. The right way is the one that works, whatever that is for each of us.


I agree that clipping leaf tips works, but it’s not the optimal method. It only serves to hinder the cloning process. The method was originally conceived to reduce transpiration and help in aried climates. But that’s not what happens when the leaf tips are clipped.

I take 10" clones, 1,000-2,000 at a time, so they are 8" when I stick them. That way, I don’t exceed my plant counts because 8" is considered an immature plant under MRMTA rules in MI.

I clip leaf tips if they’re crowded to prevent disease, whether in a clone dome, aerocloner, or over-head misting of large clone beds (like in commercial floriculture). Considering the physiological effects, it makes sense that reducing the already limited leaf tissue isn’t beneficial to the process.

By the way, I didn’t mean anything by “Don’t be a dip; just don’t clip!” I just thought it was a funny saying with an enjoyable cadence. I made it up myself, and I didn’t mean to offend anyone. I apologize if you were offended. :peace_symbol:

Check out this study. It’s great. They studied a few different cloning processes, including clipping leaf tips. I linked to it in my post:

And just because we’re on the topic of cloning, this study by Paul Cockson and his peers is good, too. Although, it’s not as thorough as the above study. Larger caliper stems and sub-heating:


Clipped leaves on the left, no clipping on the right, clones cut at the same time. So, yes, it looks like a little more roots with the unclipped, but the difference is not all that much.


Nice. Is that your pic?

I agree the difference may not be exceptionally significant for some cultivars and different cloning methods (aero vs. substrate). But at scale, when we’re talking about a few thousand clones at a time that all need to be robust, it is beneficial. And besides the effect on root growth, photosynthesis, etc., clipping leaf tips for thousands of plants adds a good amount of work and time. It can stick a thousand clones quickly, but if I have to clip leaf tips, even in bunches, that considerably reduces my work efficiency.

Here’s one more great resource on the topic of cloning. This thesis is stellar! Check out the sections on cloning in rockwool vs. peat, etc. Also, the section on CO2 supplementation is excellent. Overall, this is one of the best theses studying cannabis I have ever read, and it’s only for a Master’s degree.

I look forward to reading her P.h.D thesis :slight_smile:

Hoogenboom, J. (2022). Horticultural Management and Environment Control Strategies for Cannabis (Cannabis sativa L.) Cultivation. University of Guelph, Guelph.


Yes, pic is mine, clones from an aerocloner.

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Someone sent me a DM asking how they can buy the ebook. The ebook is DRM protected (VBK file format), so it’s not a strightfoward process to buy and read the ebook. I’ll share how, below:

  1. But the ebook from Routledge: Handbook of Cannabis Production in Controlled Environments - 1st Editi

  2. After you buy it, you need to make an account at VitalSource Bookshelf Online

  3. Then download their phone or desktop app to read the book (it’s DRM protected as VBK file format):

  4. Enter the emailed code you get from Routledge into your VitalSource app and the app will download the ebook. You can read the book from the app.

  5. You can break the DRM protection from the app and convert it to PDF format using: Epubor Ultimate

Breaking DRM protection is no longer illegal in many cases: Court: breaking DRM for a “fair use” is legal | Ars Technica

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if those “scientists” dont get near 100 percent clone rooting success regardless of snipping leave tips then they dont know how to grow. Id trust real growers vs academics all day long.