The easing of prohibition laws worldwide has opened the floodgates to investigate the science of cultivation in a way that has never been possible before. While ushering in this new age of cannabis research we can draw on well-established data and best practices from other horticultural crops.

“Crop steering” is a technique that draws from various horticultural disciplines and is currently underutilized in commercial cultivation. We’ll dive into how crop steering can be applied to commercial cultivation, best steering practices based on the latest research on cannabis and other crops, and an overview of how environmental and irrigation control systems can be optimized, integrated, and automated for the most effective crop management.

What is Crop Steering and what are the benefits? 

Crop steering is a data-driven form of precision agriculture that uses subtle environmental cues, lighting strategies and irrigation techniques to “steer” crop growth and development to meet grower objectives. In other words, crop steering is the science of exploiting the plant’s hormonal responses by altering the controlled environment. Early adopters of this method in the cannabis industry are reporting record yields and unprecedented control over their plants.

The precision of crop steering is ideal for continuous improvements to plant performance and profit margins based on quantifiable goals and outcomes. Directed plant growth offers an exciting opportunity to revolutionize the way the crop is grown on a commercial scale. Because steering is based on changes to the environment, lighting and irrigation strategies, it does not require any additional inputs beyond irrigation and environmental and lighting control systems. After suitable control systems are in place, practicing this method costs virtually nothing and can greatly increase yields and cannabinoid production.

Cannabis and crop steering make an excellent match for a variety of reasons: biological, technical, and economic. The way commercial cannabis is typically grown is particularly well suited to steering techniques but first, it is important to understand the lifecycle of the plant and the forces that drive it. You can dive deeper into the biology and lifecycle of cannabis in our white papers covering crop steering, plant water relations, plant metabolisms, and the root zone.

Crop steering basics: Vegetative vs. Generative Steering

To better understand crop steering, you need to know the difference between vegetative and generative growth. That’s because the key to properly directing plant growth is to apply stress that will promote generative growth without sacrificing yield or cannabinoid production. To be more specific, stress is applied to stimulate generative growth by intensifying the growing environment while vegetative growth is promoted by eliminating stresses by creating a mild, abundant environment.

How to properly steer crops: Irrigation & environment

Water is the basis of everything in cultivation and it is a key principle in crop steering. That’s because it’s used to simulate water scarcity without inflicting any drought stress. More specifically, we want to pay attention to water potential, which is a measure of how easy or difficult it is for water to move. In the context of roots, it can be understood as how hard the plant needs to pull to draw water out of the root zone. Dive deeper into irrigation and matric vs. osmotic potential in our comprehensive Crop-Steering White Paper.

Along with precise irrigation, crop steering requires proper, balanced environmental set points that modulate mild stress. The environment can be used to manipulate the availability of water, leading plants to perceive either an abundance or scarcity of water or can be used to directly steer crops. Temperature and relative humidity are used to calculate vapor pressure deficit (VPD). Higher temperatures raise VPD and higher RH lowers VPD and vice versa.

HOW TO MANAGE THE GROW ENVIRONMENT

Crop management, in general, is easiest with consistent growing environments. Consistency is important spatially (throughout the growing space) and temporally (over time). This is especially true for crop steering because it is based on using the environment to influence plant growth and development. At the end of the day, consistency is achieved through good design and management of growing spaces and environmental controls.

Controls

There is a huge spectrum of controls a grower can use to manage irrigation and the environment. On one end of the spectrum are completely manual controls. On the other end of the spectrum are fully automated controls that are orchestrated by complex computer programs to work together to create a consistent environment. At the end of the day, crop steering is most effective with fully integrated systems that use continuous monitoring to automate controls.

The simplest and least expensive form of automation is timers. When environmental factors require more dynamic settings, like temperature and humidity, an integrated environmental control system is a better choice. Producers of environmental control systems like IOGRU have created control systems tailor made for the specific needs of cannabis cultivation.

Sensors

Much like how a grower observes their crop and takes note of changes in the growing environment, environmental sensors are central in the decision-making process of environmental control systems. Crop steering is a data-driven system and sensors are the source of the data. It is important to keep in mind, however, that a control system is only as good as the information it is receiving. Sensors must be both accurate, and representative of the growing environment. Ideally, sensors should experience the same environment as the plants.

Some of the newest technology in cultivation sensors combines optics and artificial intelligence to monitor crop health and development. This technology has been used in agronomic field crops for a few decades and has been used to automate post-harvest quality control for various horticultural commodity crops. The idea behind this technology is that it can be trained to detect pests, diseases or physiological problems in crops by using color and shape data collected from cameras.

Monitoring

 As with controllers, there is a wide spectrum of technology for monitoring the grow
from completely manual pen-and-paper measurements and records to fully automated systems that track data points every couple of minutes. Crop steering is a data driven approach to growing so the more data that can be gathered, the better.

 This data is useful for:

• Verifying systems are working properly
• Diagnosing issues with systems
• Tracking how changes to environmental factors affect each other (e.g. how does raising the temperature affect dry down?)
• Tracking how changes to environmental factors affect growth factors (yield, quality, etc.)

While irrigation systems typically log data within the system like the pH, EC and volume of water delivered, it does not always track data after the water is delivered to the crop. Therefore, data from the root zone and runoff brings the precision with which a grower can steer their crop to a new level. Various root zone monitors are available that integrate with other systems to varying degrees.

How to Source the Best Crop Steering Technology 

The better control a grower has over their environment and irrigation the better positioned they are to profit from crop steering. More specifically, the benefits of crop steering should be taken into account when considering retrofits to existing control systems or designing new systems. All growth factors must be in balance to achieve optimum results, which is possible with technology that can automate all aspects of irrigation and environmental controls.

Automated controls, sensors, and monitoring can be integrated into technology systems, but it will still require knowledgeable and skilled growers to make decisions. RMJ Supply’s team of cultivation experts can help you source and integrate everything you need for successful crop steering. Our comprehensive platform improves overall performance through access to our trusted supplier network, a diverse team of industry experts, and a reduced total cost to build, expand, and operate commercial CEA facilities. Learn more about our equipment system offerings and contact us to get started with a proposal. 

Want to dive deeper into the biology and latest research surrounding the concepts of crop steering?