Rhizobacteria and Yield Improvement

The cannabis market has skyrocketed in the last few years, with more people in the United States supporting legalized marijuana and using hemp products than ever in history.

Increased Demand - Yield Increase in Plants

While marijuana, with its high THC levels, has yet to be federally decriminalized, a majority of states have legalized the beneficial plant either recreationally or medically. The National Conference of State Legislatures counts 36 states and four territories that allow for the medical use of cannabis products. Eighteen states, two territories, and the District of Columbia allow for nonmedical use as of publication — and work continues for more.

This increased demand has inevitably led to more commercial farmers and entrepreneurs looking to increase their yield in plants and thus supply. Even though growers have sown cannabis seeds for centuries, science is always innovating and creating more to learn about efficiency and how to increase cannabis yields in cannabis production. 

Today’s cannabis cultivators are integrating new technology into their growth schedule. Instead of relying on harmful and unnatural chemicals, these commercial farmers now use beneficial microbes to avoid the environmental concerns from concerned communities throughout the globe. Cannabis production is increased, and the growing demand is even closer to being met.

As the traditional agricultural industry accepts new processes, American cannabis growers can use independent, scientifically grounded researchers for details on biostimulants and crop responses. These third-party technicians are interested in improving crop productivity and resiliency. They can teach even seasoned farmers how to cultivate cannabis better than they ever have. 

People who use cannabis as part of their daily health regime do so for a variety of reasons. But for those who are working the fields, business is always the bottom line. Whether you grow marijuana or hemp, the cannabis crop is simply a matter of creating an optimum ROI. That’s just another reason to integrate biostimulants and plant growth regulators. Enhanced profitability from more abundant crop yields is a benefit of this new technology.

In this cannabis cultivation guide, you’ll learn the power of combining beneficial microbes, cannabis cultivation, and bacterial inoculants. Along with providing growing tips for optimal plant growth, we’ll answer common questions like:

  • What is the role of biostimulants in plants?
  • What are the best microbes for cannabis?
  • What are the best plant biostimulant products?
  • What is the step-by-step process for biostimulant plant growth?
  • What are other best practices for a yield increase in plants?

Feel free to skip ahead to a specific question or start at the beginning to dive deep into beneficial microbes cannabis needs for optimum growth.

What is the role of biostimulants in plants?

Most cannabis customers don’t want their marijuana or hemp products to be laced with chemicals like chemical fertilizers, pesticides, or herbicides. They’re interested in organic growth methods not only for their own health but also for the health of the environment.   

Still, farmers with all sizes of land know that many growing beds need extra attention. Plants may have symptoms of stress, such as yellowing, dropping leaves prematurely, or not developing strong stems and blooms. Insects and weeds swarm stressed crops. 

The solution isn’t adding more chemicals. Biostimulants are the solution. To explain the role of biostimulants in plants and their growth cycle, let’s start with a clear definition of this new technology.

What are biostimulants?

A biostimulant is a product used in agriculture to make nutrition more bioavailable for plants while improving their stress tolerance and enhancing the genetics of the seed stock. 

Instead of adding an extra substrate containing a certain percentage ratio of the nutrients plants need, a biostimulant works instead to improve the environment in which the plant is growing. 

Think of the last time you had a stomachache from eating a suspect meal. Instead of a spoonful of soothing pink chemicals to temporarily relieve the discomfort, the biostimulant would be like eating a cup of Greek yogurt to add good bacteria to fight the bad bacteria in your digestive tract. 

Biostimulants contain beneficial microorganisms that improve soil conditions. These could include beneficial bacteria and fungi, microbes from liquid manure composting, seaweed extracts, or humic and fulvic acids.

Healthy soil provides the environment roots need to provide adequate nutrients and water to cannabis plants. When the rhizosphere is a balanced, fertile substrate, visual symptoms of stress in plants are reduced. This results in a greater crop yield at harvest.

How do I know if biostimulants can work on my land?

A common first step to working the land is to have the soil tested to determine, among other things, what nutrients are lacking and the salinity content. This understanding of the land is necessary for calculating the amounts of adequate fertilizer and soil amendments. So, it can be hard to believe that biostimulants can benefit all kinds of soil.

All fertile land, at least the rhizospheric level of the soil, is actually a complex ecosystem of bacteria, viruses, fungi, and microscopic critters. Dig your hand in your dirt, and you’ll find worms and insects that sometimes compete with your root structure but sometimes are beneficial to growth. 

The bacteria in biostimulants are the beneficial kind, helping to balance out the bugs that disrupt the balance of the ecosystem. That’s especially important in soils with high salinity levels, inconsistent watering patterns, too much sand or silt, or land that hasn’t benefited from best agricultural practices in recent years. 

Farmers today use biostimulants as both additions and replacements to current fertilizer programs. Often, it’s advisable to start with a test row of crops to see for yourself the role of biostimulants in plants. Measure the dry weight yield, growth rate, and stem diameter — along with other quantifiable data — to see if biostimulants work as well on your cannabis plants as with others.

What are the best microbes for cannabis?

Cannabis plants are hardy by nature and able to adapt to many different growing environments, but you need the right microbes in the soil and special growing conditions for the most productive crops. To know what’s best for a particular climate, the first thing to do is have an in-depth understanding of the microclimate under which a farm operates.

To know the best microbes for cannabis, like so many things in agriculture, you must plan around the seasons.

How do seasons relate to biostimulants?

While cannabis is relatively tolerant of heat, the plants delay growth when temperatures are above 88 degrees or below 60 degrees Fahrenheit. This can overlay with a general rule of planting in the middle of spring in the Northern Hemisphere with a harvest planned for the middle of fall.  

Seedlings will begin to enter the vegetative state as the hours of sunlight increase as the year progresses toward the summer solstice. After June 21, the daylight hours decrease. When it receives less than 15 hours of sunlight a day, most cannabis strains take the cue as a time to begin to flower.  

For each of these phases, the plant and its root structure have specific demands on the soil. That’s why Impello offers three blends of its microbial inoculant: Tribus Original, Tribus Grow, and Tribus Bloom. While the original formula is designed to be used throughout the growth cycle, Tribus Grow is focused on increasing vegetative growth. Farmers can switch to Tribus Bloom once the flowering phase begins and use it until moments before harvesting.

What microbes are in a microbial inoculant?

Let’s look more closely at Tribus Original to see what exactly is in a biostimulant. Impello created a proprietary blend of bacteria to support plants starting at their roots. The three strains are:

  • Bacillus subtilis
  • Bacillus amyloliquefaciens
  • Bacillus pumilus

  • This combination of microbes will produce enzymes and biochemicals that grow in the rhizosphere area of the soil. This provides the right environment for roots to uptake the macronutrients that already exist in the soil. This leads to proven stem and root growth, as well as a better growth rate and higher resiliency overall.

    These microbes improve levels of atmospheric nitrogen while making phosphates in the soil more easily absorbed and utilized by the roots of cannabis plants.

    How can I tell if my soil needs microbes?

    It doesn’t matter which microbes are the best for cannabis if you aren’t sure if your soil needs microbes. The way to determine if soil needs microbes is to analyze the overall health of the soil.

    Look for the following qualities in your soil to know if it could benefit from a biostimulant:

    • Soil is lighter in color, not very dark brown
    • The texture is either too sandy or too silty
    • The soil clumps and holds too much water, or lets too much water drain away
    • It’s too acidic or not acidic enough. It should be around 6.

    If you have used an all-in-one fertilizer in the past, chances are the soil is also too high in nitrogen for cannabis in its flowering cycle. Likely, the use of this unnatural chemical additive has also caused harm to the beneficial microorganisms in the soil. Adding more will improve the health of the soil — both in the short and long term.

    biostimulants and crop responses

    What are the best plant biostimulant products?

    Once cannabis farmers decide to integrate a biostimulant into their growing routines, the next obvious question is to pick one of the many on the market today. There are a few important things to look for when choosing the best plant biostimulant products.


    In-house research and development 

    Biostimulant companies that put the extra effort into researching and developing proprietary blends are more likely to create supplements for your soil that work. Impello, for example, works directly with farmers to gain important feedback as they expand their catalog of biostimulant products.

    Consistent, documented usage and experimentation with these products have resulted in huge advancements in organic farming, especially when combining microbial inoculants with soil amendments and organic nutrients. If you want to know how to grow large marijuana plants, look for biostimulant products that have been developed, tested, and implemented with success.

    Independent testing and certification

    So many companies will do their own research and declare their products a success, but any business owner knows that third-party testing is more reliable. You’ll want to look for a manufacturer that isn’t scared to share the results of independent testing in a qualified research laboratory.

    For example, Impello uses third-party testing but also goes a step further. They partner with the Organic Materials Review Institute, or OMRI, to list their products. This nonprofit organization reviews products to determine acceptability in certified organic production and processing facilities. 

    Independent tests for Impello’s Tribus blends found:

    • 15% increase in dry weight yields 
    • 14% increase in growth rate, and 
    • 16% increase in stem diameter 
    • 10% reduction in fertilizer usage
    • Increased terpenes

    That said, the products should also be USDA-certified as a biobased product and GMO-free. 

    High concentration of active ingredients

    When it comes to ROI, the most important calculation is determining the amount of the product needed for a measurable improvement in crop yield. If you have to use a massive amount, it simply won’t be a cost-effective plan.

    Look for a biostimulant that is highly concentrated with active bacteria. The point of these products is to allow the rhizobacteria to colonize within and around the root zone to enhance nutrient uptake. If there aren’t enough active ingredients (in terms of colony size), the product won’t do what it claims to do.

    A product should contain 10 billion colony-forming units per milliliter of living bacteria.

    Guaranteed satisfaction

    Like researching so many other products, be sure to look at the verified customer reviews from fellow commercial growers to see what others have to say about their experiences. For example, farmer Amanda B. used Tribus Original and found dramatic results.

    “I love how easy this product is to apply as opposed to prepping compost tea,” she wrote. “Also really nice to be able to give my in-ground girls a nice foliar feed of aminos … They perked right up and the growing tips deepened a shade or two of green.”

    Joshua O. wrote that he was “blown away” by the results of Tribus combined with Impello’s bio-based fertilizer Lumina.

    “I’ve been using Tribus for a couple years now and have had amazing results,” he wrote. “I’m actually blown away by the results I have from using Innate Grow/Bloom along with Lumina and the Tribus Grow/Bloom microbes. I strongly advise fellow growers to try any product Impello Biosciences has to offer.”

    But don’t simply rely on what customers write. A reputable company should offer a full money-back guarantee if you are not as pleased as the other cannabis growers who use the same biostimulant.

    What is the step-by-step process for biostimulant plant growth?

    Biostimulants can be used throughout the entire life span of the cannabis plant. You may simply want an overall improvement in your bottom line, or you may be interested in addressing a specific concern with your plants or soil. Know what measurable benefits you seek, so you can know which steps to take and how to determine success.

    Through its independent research, Impello has noted the following benefits of biostimulant products for commercial farmers:

    • Increased crop yields
    • Increased nutrient uptake
    • Increased water uptake
    • Increased flower quality (thanks to enhanced nutrition)
    • Increased plant tolerance to abiotic stress
    • Improved root structure and development
    • Reduced shock from transplantation
    • Improved root development of clone stock
    • Reduced nutrient usage
    • No build-up in the soil

    These individual benefits can also lead to improved profitability for your farm. But how do you start?

    Step 1: Implement a test area in your farm

    Follow the lead of researchers studying the cannabis plant’s growth patterns and positive impacts of health when adopting new technology. Use the scientific method to determine success when integrating biostimulants on your farm.

    Pick a growing bed or area of plants to test the hypothesis that biostimulants improve your cannabis plants based on the benefits listed above. Make sure that the other factors, such as watering schedules and light availability, are the same. 

    Step 2: Plan for the season to schedule appropriate biostimulants

    No successful agricultural operation runs on autopilot. Every year, land managers must consider changes to climate and seed stock variations, not to mention market fluctuations, labor concerns, and so many other variables within the industry. Adding soil amendments is no different. Plan for the entire growth cycle before seeds or seedlings go in the dirt.

    For the largest benefits, add Impello’s Tribus Original to the soil at the earliest stages of the plant’s life cycle. This is because the good bacteria will begin to establish colonies within the soil and near plant roots right away. As the roots grow in search of additional nutrients and water, regular application will serve as a supplement to your normal fertilization program.  

    Once the cannabis seedlings have become established and begin their vegetative growth cycle early in the season, many farmers will switch the biostimulant product to Tribus Grow for a better yield increase in plants. After the summer solstice and the plant transitions to the blooming phase, consider Tribus Bloom.

    Adding these changes to the monthly and daily calendar makes a plan for success. 

    Step 3: Add Tribus Original to your watering system  

    Before using a liquid-based biostimulant product, make sure to shake the container as Bacillus spores tend to settle naturally. You’ll want to use between 0.5 to 2 milliliters per gallon of water, depending on the density and stress levels of your crops. It’s possible to premix a solution, but for best results, it should be used within 24 hours.

    Impello’s biostimulant blends work in all kinds of farms, including hydroponic, soilless, and traditional soil-based systems. It can be applied with all kinds of irrigation methods as well, whether mixed in as part of an aqueous nutrient solution or applied directly to the rhizosphere level of the soil around the roots.

    Tribus can be used as roots first start to grow, as the beneficial bacteria colonies help to mitigate stress, encourages rapid plant growth, and aids in strong root development. You can apply biostimulants all the way to harvest day. 

    Use at least once a week, or as frequently as every watering.

    Step 4: Harvest and determine success

    Biostimulants and plant growth: are they connected? Scientific studies and cannabis farmers who supply reviews agree, but none of that matters if it isn’t working on your farm. The final step in finding success with plant biostimulants in any marijuana plant growing kit or operation is to measure your harvest.

    Compare the plant stock and dry yield in the test area of the farm with the baseline section. Consider the health and vitality of the plants, the quality of the flowers, and the amount of added nutrients that were necessary for each section of soil to judge for yourself. 

    Keep in mind, too, that the rhizosphere area that benefited from the soil amendment will be better prepared for the next growing season. Planning for next year, of course, is what follows next.

    What are other best practices for a yield increase in plants?

    Those who want to know how to grow large marijuana plants are usually ready to consider many methods to improve their yields. It’s the 1% Rule: You just need to be 1% better than your competitor to generate the advantage. 

    Besides integrating beneficial microbes, cannabis industry professionals also recommend these other best practices:

    • Plant directly in the ground or in five-gallon fabric pots (or larger)
    • Create a sheltering structure for the potential of extreme weather conditions in advance of a crisis
    • Add only plant-based fertilizers that have proven success specifically with cannabis plants 
    • Monitor watering to avoid droopy leaves or overly dry soil
    • Clear a buffer area around your growing zones to avoid pests on the plants
    • Maintain a fence to keep out larger critters
    • Keep a layer of mulch around plants to limit weed growth
    • Stay up to date on legal regulations 

    The Bottom Line: Biostimulants are how to grow large marijuana plants

    You aren’t alone in wanting to learn how to grow marijuana and hemp. The data site Statista.com reports there were nearly 17,000 farms in the United States with cannabis cultivation licenses in 2019. One way to stand apart from the competition is with the benefits of biostimulant plant growth.

    The role of biostimulants in plants will likely grow in popularity as the agricultural industry continues to modernize and research becomes more focused. Until then, individual farmers and growers must learn independently about the best microbes for cannabis and the best products to use. 

    By integrating the power of nature and other best practices into this growing season, it’s possible to reap the greatest harvest of cannabis production yet. 

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