Multi-Spectral Technologies for Cannabis Cultivation

by | Sep 21, 2021

Written by Jessica McKeil

Jessica McKeil is a cannabis writer and B2B content marketer living in British Columbia, Canada. Her focus on cannabis tech, scientific breakthroughs, and extraction has led to bylines with Cannabis & Tech Today, Terpenes and Testing, Analytical Cannabis, and Grow Mag among others. She is the owner and lead-writer of Sea to Sky Content, which provides content and strategy to the industry’s biggest brands.

Hyperspectral, multispectral, and spectral imaging are all terms you'll see thrown around in the commercial ag sector, but that all cover the same technology — imaging devices used to capture and analyze information from specific bands within the electromagnetic spectrum

This data helps growers efficiently assess their canopy for pests, pathogens, and other deficiencies — all without the painstaking plant-by-plant inspections traditionally required. Instead, it's fast, minimally intensive, and delivers high-quality data for crop management.

What is Multi-Spectral Technology?

Humans can see the electromagnetic spectrum in quite a narrow band, between 380 nm to 780nm – the spectrum a traditional digital camera would capture: red, green, and blue. Multispectral imaging incorporates information available outside of what the human eye and digital camera will capture— in the ultraviolet and infrared areas and beyond.

Other areas of the spectrum provide more information than what the human eye will see, especially regarding plant health. Naturally, plants reflect and absorb different bands of light, which can indicate health issues, stress, and stage of growth. Multispectral technology captures that data to provide precision analytics to growers and their investors.

How is Multispectral Technology Used for Cannabis Cultivation?

Originally, the only way multispectral technology was applied to the cannabis industry was to detect illegal operations. In the early '00s, several papers tested the potential of this technology for differentiating between cannabis plants and the surrounding vegetation. It remains a valuable tool for law enforcement in their quest to identify hidden cannabis plantations.

But as legalization spread over the last few decades, so too did legal cannabis plantations. These days, there are tens of thousands of acres of legal cannabis and hemp planted across the country, and cultivators are adopting the same multispectral technology used by law enforcement — but for very different reasons.

In cannabis, multispectral technology is inserted into drones, cameras, and grow lights to help growers cover more ground and get detailed insights into their canopy health.

The following are just a few examples of how cannabis and hemp producers are applying this innovative tech:

Clone Propagation and Inspection

Several companies like Emerald Metrics are adopting spectral imaging for indoor cannabis operations. Using a combination of sensors and spectral imaging devices, Emerald Metrics helps producers monitor plant health and, interestingly, analyze clone health.

Their proprietary table-unit technology determines which clones offer the highest propagation potential and others that may pose risks to the entire operation. This is an innovative way to cut down on the risks for cultivators that rely on third-party clones as well as for the clone producers who sell them.

Indoor Grow Light Technology

Other areas for multispectral technology inside an indoor facility are within smart lighting fixtures. For example, Agnetix, a company developing liquid-cooled LED lighting systems, recently launched a new grow light series called Zenith, implementing multispectral technology.

This new line of LED grow lights uses reflected light intensity and color sensors (among others) to help growers make intelligent and responsive decisions about lighting, plant care, and more.

Future versions of Zenith will incorporate an imaging camera to capture close-ups to efficiently detect deficiencies, plus an advanced multi-wavelength LED flash and illuminator technology with UV & IR inspection capabilities.

Drone Crop Management

Out of all the possible applications for spectral imaging technology in cannabis and hemp, drone-based systems are making the most impact. Several companies, like Precision Hawk and SkySense, are already using this technology for hemp.

Crop inspection for pests, pathogens, nutrient/water deficiencies, and general plant development is traditionally labor and time-intensive. Deploying drones capable of multispectral imaging provides producers with timely, precise, and accurate reports on overall canopy health and problem areas.

Most drones use MicaSense RedEdge sensors to gather, process and report on vegetation. These reports help farmers eliminate or treat areas of concern, efficiently apply fertilizer, and more.

Multispectral Imaging for Cannabis and Hemp

Drones are just the beginning of spectral imaging in the hemp and cannabis sectors. With this technology getting packed into indoor applications and grow lights, soon more than just sun-grown cannabis will reap the data-driven benefits.

Multispectral imaging gives producers an effective and efficient means to monitor crop development in a way that was never before feasible. It's an imaging technology that can assess well beyond what the human eye perceives.