(Written by Anthony Domangue)
Airflow and Disease Management
Canopy Management Under High-Light Intensity
Canopy management is an over-arching name given to a series of processes throughout the plant life cycle, including integrated pest management practices, removing foliage for a desired outcome, and establishing plant support structures. Each of these processes plays a massive role in the productivity of your plants and involves various cannabis cultivation techniques. This FOHSE blog will cover the different aspects of canopy management and plant training techniques, and how to use these practices to improve plant health, crop yield, and quality.
Plant Training
Training your plants involves a set of cannabis cultivation techniques aimed at optimizing plant structure, improving light exposure, and increasing airflow to improve flower yield and quality. Let’s talk about a few of these methods in more detail.
Low-Stress Training
LST or low-stress training is a canopy management strategy that involves gently bending malleable branches and stems to redirect the main stem and encourage the growth of lateral shoots along the branch upward.
This plant training technique allows growers to safely manipulate plant structure while improving light penetration and airflow in the canopy. It’s ideal to implement this strategy during vegetative growth or early flowering before branches lignify.
High-Stress Training
High-stress training are plant training methods that greatly stress the plant and without the proper actions taken can easily result in crop loss. These cannabis cultivation techniques require careful execution to ensure a successful yield.
Pictured above is a Runtz female in late flower that has been super cropped. By growing sideways, it puts each lower flowering site much closer to the top cola, thus increasing the uniformity of the flowers. This method of canopy management is essential for optimizing light distribution and improving overall plant health.
One popular plant training method is called supercropping. Supercropping refers to a technique that involves intentionally stressing the plant by gently bending and pinching the stems. This ultimately helps growers maximize the yield and quality of their flower, but can also be used to control plant height. These plant training techniques are integral to advanced cannabis cultivation techniques aimed at achieving the best possible results.
Defoliation and ThinningÂ
A major aspect of canopy management is defoliation and branch removal. This involves deliberately removing leaves and branches from plants to induce a certain response from the plant. Pictured above is a room of GMO plants that were heavily defoliated after early flowering.
This technique is primarily used to manage the growth and structure of the canopy. Here are some ways defoliation plays a critical role in the garden:
- Light Penetration: One of the primary reasons for defoliation is to improve light penetration within the canopy. Dense foliage can lead to lower leaves, branches, and flower sites shading, reducing their access to light. By selectively removing some, more light can reach the middle to lower canopy, promoting greater rates of photosynthesis, fruit development, and overall health. Effective cannabis cultivation techniques often emphasize the importance of light penetration for maximizing yield.
- Air Circulation: A dense plant canopy can create a humid microclimate within the plant, increasing the risk of fungal diseases as temperatures and humidities increase. By thinning the foliage, air circulation is improved, reducing humidity and minimizing the chances of disease development. This is particularly important in preventing conditions that favor diseases like powdery mildew. Plant training techniques, such as defoliation, play a crucial role in maintaining proper air circulation.
Flower Quality and Yield: For fruit and flower-bearing plants, defoliation can increase their size and quality. When excess foliage is removed, the plant’s energy is directed toward fruit development instead of maintaining unnecessary foliage. Canopy management and plant training techniques are essential for optimizing flower quality and yield in cannabis cultivation.
Defoliation can be beneficial or detrimental depending on how much plant material is removed and the plant species you are growing. Cannabis plants typically benefit from defoliation and branch removal, but each cultivar will have its preference. Some prefer less removal, while others may need intensive removal for optimal yield and flower quality. While several varieties of berries, cannabis, and other types of plants can benefit from defoliation, not all types of plants benefit from defoliation. Some plants like corn can have yield reduced by defoliation.
Each grower must have an intimate understanding of each plant type and variety they are growing to determine the proper amount of defoliation needed to manage the plant canopy properly. Understanding cannabis market trends and adopting appropriate cannabis cultivation techniques are essential for growers aiming to maximize their yield and profitability.
ToppingÂ
Topping is a generalized term that describes removing the top portion of branching or meristem to encourage the growth of multiple new main branches. The goal of this method is to increase the uniformity of the canopy, increase flower size, and promote a better plant structure. This technique is a crucial aspect of canopy management and is one of the effective cannabis cultivation techniques.
The traditional method of topping involves taking a clean blade or scissors and cutting the stem just above the growth node. This will signal the plant to push lateral shoots upward, ultimately developing the lateral growth into new main stems. This is a fundamental plant training technique.
Fimming
Another method of topping is called “fimming,” which stands for “Fuck, I missed!” This method was likely developed by accident. As the first growers to find this phenomenon attempted to execute a traditional top, a cut is instead made into the new growth as opposed to below it.
This method can produce exponentially more new main tops than a traditional topping, leaving growers with three to five new main growth shoots as opposed to two. This technique is widely used by the home-growing community and is an essential part of effective canopy management and cannabis cultivation techniques.
Integrated Pest Management
IPM or integrated pest management is a holistic and sustainable approach to managing pests and diseases in the garden. It focuses on minimizing the use of synthetic pesticides and combines various strategies to effectively control pests while reducing the impact on the environment and non-target organisms. IPM plays a crucial role in canopy management and plant training techniques by helping maintain healthy canopies and promoting optimal plant growth. A good IPM regiment requires a series of tasks to accomplish:
Biological Control
Introducing specific microbes, predatory insects, and parasites to the foliage and root zone of your plants and encouraging their proliferation ultimately suppresses harmful organisms while promoting plant health and vitality.
Neoseiulus californicus and Phytoseiulus persimillis are two very common predatory mites used to mitigate the presence of spider mites and thrips. Another predatory mite, Amblyseius swirskii, can also be used to target various species of thrips. Certain parasites like nematodes can be applied via foliar sprays in an effort to reduce pest and disease pressure.
By encouraging populations of beneficial microorganisms and insects, you can reduce, if not eliminate, the need for synthetic intervention in your growing space.
Daily Crop Walks
Nothing beats the attention of the grower. Walking your crop daily allows you to closely observe the plant foliage, substrate, and general growing area for signs of diseases and pests. This is the catalyst for timely intervention before problems escalate.
Neglecting to walk your crop will ultimately result in a lack of awareness about what is happening in your growing space and a lack of intimacy with the varieties of plants you are growing.
Establishing Decision-Making
IPM is the central guide for action-setting thresholds and predetermined pest populations for many small-scale operations that cue the grower’s intervention. This prevents unnecessary treatments and allows for a deliberate and efficient response.
However, as companies begin to scale the footprint of their cultivation facility, preventative measures must be taken regardless of the active levels of pest or disease pressure. Applying IPM principles can lead to healthier plants, reduced pesticide reliance, enhanced ecosystem resistance, and more sustainable and productive cultivation facilities.
Trellis and Support
Trellis and support structures are integral to canopy management practices in agriculture and horticulture. They provide physical support to plants, guide their growth, and help optimize canopy structure for better light exposure, air circulation, and overall plant health.
Trellising and support systems are commonly used in vineyards, orchards, and cannabis cultivation facilities to train plants to grow in specific directions to facilitate easier maintenance and harvesting. Here are a few ways trellis and support structures play a role in canopy management and cannabis cultivation techniques:
Airflow and Disease ManagementÂ
Properly manipulating the plant’s structure through trellis netting or opening up plants properly. Improving the airflow within your canopy effectively mitigates the risk of pathogen proliferation and increases overall plant health.
Canopy ControlÂ
Trellis netting and support structures allow gardeners to manipulate the plant canopy easily. This improved control allows for optimized crop yield and quality.
Light Distribution
With proper defoliation strategies, the plant canopy can be manipulated to increase light distribution into the mid to lower canopy greatly.
Supporting Heavy Flower
As time passes during the flowering cycle, cannabis flowers increase in weight, which demands the need for trellis netting, and other types of support structures help to hold up the increasing branch weight.
Some plants, like those within the Cucurbitaceae family, have tendrils or slender threadlike appendages, often growing in a spiral form, stretching out and twining around suitable support. Other plant varieties, such as cannabis, don’t have tendrils, but they still respond well to plant training under and through trellis netting. Each gardener should research the plant variety grown well to understand the ideal support structures needed to optimize growth.
Canopy Management Under High-Light Intensity
Every light has a different spectrum and potential for power. As plants translate these changes, excellent yield, morphology, and quality variances can occur from variety to variety.
High light intensity plays a major role in canopy management practices. When converting from one lighting system to high-output LEDs, growers need to consider what changes are occurring and how to leverage them to their advantage. For cannabis growers, consider the following:
Plant Morphology
Light intensity plays a massive role in the structure of your plants. If you’ve ever seen a plant not getting enough light, you may notice a tall plant with large distances between nodes. This is because plants have preferred light intensity values throughout their life cycle. When these targets aren’t met, plants stretch upward until they reach their desired light intensity.
On the other hand, plants that receive enough light for growth will remain compact and have much shorter distances between growth nodes. With this in mind, light intensity can be used to achieve a specific plant structure. If you have varieties that you’d like to stretch more, a slightly lower intensity will induce that morphology. To compact plants, delivering a light intensity close to the saturation point for that growth stage is ideal. Effective cannabis cultivation techniques, including canopy management and plant training techniques, can help achieve the desired plant morphology.
Crop Consistency
Product uniformity and quality are central to all cultivation operations. Although this is the goal, uniformity is not an easily achievable feat. One way growers can increase product uniformity is to decrease the difference between the flowers with the most and least light intensity.
Most cannabis cultivators target between 900-1100 micromoles for a peak light intensity target. With top colas at those intensity values, it’s ideal to keep your lowest flowers around 300 micromoles to ensure the highest degree of consistency. Dipping below 300 micromoles typically results in poor flower structure and quality. Adequate defoliation practices and quality light sources will ensure you meet your intensity targets from the lowest to tallest flower sites. Implementing effective plant training techniques is crucial in maintaining consistent crop quality.
Light Intensity as a ToolÂ
The intensity of light delivered to your plant canopy during mid to late flowering gives different cues that tell each plant to either produce floral tissue or to ripen.
It’s advantageous to utilize peak light intensity values during mid flower in an effort to promote yield during the bulking stage. High light intensity during late flowering will NOT encourage the natural ripening process that takes place during the last few weeks of the flowering cycle.
On the equal and opposite end, lower light intensity values can impact the growth and quality of your plants. Implementing these cannabis cultivation techniques effectively will ensure optimal results throughout the growth stages.
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