Preventing Bud Rot – Essential Tips for Cannabis Producers

Bud rot, aka gray mold, is an extremely common problem in cannabis cultivation. It’s a humidity-related disease that affects greenhouse and indoor production and can destroy entire crop cycles.

Bud rot is a prevention is arguably the biggest issue in cannabis cultivation. Bud rot (botrytis cinerea) is an incredibly wide-spread disease, affecting a wide range of crops, including cannabis. It’s a type of mold, similar to powdery mildew and downy mildew.

Cannabis is highly regulated, meaning producers can’t use traditional fungicides to combat molds. Therefore, the only GMP approved solution to bud rot is through environmental, or climate control. Maintaining low relative humidity levels, using active dehumidification, prevents mold outbreaks by limiting the conditions bud rot needs to develop.

Causes and Risks of Bud Rot in Cannabis

Bud rot develops in cannabis when botrytis cinerea, a type of fungal pathogen, infiltrates the plant. It then develops inside the plant, before symptoms even become visible. bud rot will eventually cause cannabis plants to shrivel, rot, and die.

One of the biggest problems, when it comes to preventing gray mold, is that mold spores are everywhere. They travel through the air and can be found almost anywhere in the world. It can infect a greenhouse or indoor grow, just as easily as it affects outdoor plants.

So, the solution to bud rot isn’t in avoiding pathogens, but in preventing their development.

The Role of Humidity Control in Mold Prevention

Bud rot requires water in order to develop. So, the most common cause of bud rot is high humidity.

When there’s a lot of moisture in the air, and relative humidity reaches 100% (the dew point), water starts to condense on different surfaces. These include structural elements, equipment, and even the plants themselves.

Cannabis buds are especially dense. So moisture can easily become trapped, leading to condensation occurring inside the buds themselves, and creating the perfect conditions for mold to develop.

This means cannabis is especially susceptible to bud rot during the flowering stage. Though it may affect plants at all stages.

How to Detect Bud Rot – Gray Mold Symptoms

Early signs of bud rot eventually start showing on and around infected buds, darkening and softening the plant surface. After initial symptoms appear, botrytis will burst out in gray fuzzy mold.

Despite commonly infecting cannabis flowers, symptoms can appear anywhere – on plant leaves, stems, flowers, or the anywhere on the rest of the plant.

The fuzzy gray mold that develops on the plant is, in fact, millions of fungal spores. So once the mold is visible, botrytis spores are ready to travel and infect nearby plants. At this point, it’s much more difficult to stop the spread and prevent a larger outbreak.

Bud Rot Solutions for Greenhouse and Indoor Cannabis Cultivation

According to IPM (integrated pest management), prevention is always more beneficial than post-outbreak treatment.

Using a combination of the following techniques can help prevent bud rot, by decreasing its presence and ability to develop.

Prevent Molds Using Dehumidification

High humidity levels are the leading cause of bud rot in cannabis cultivation. Implementing effective humidity control solutions is critical for maintaining optimal conditions.

DryGair dehumidifiers utilize advanced condensation technology to remove excess moisture from the air at a rate of approximately 45 liters per hour (12 gallons).

By controlling moisture and preventing dew point condensation, these systems create an environment where bud rot cannot develop, ensuring healthier yields for commercial cannabis producers.

Improve Climate Conditions with Air Circulation

Airflow control, or more specifically, air circulation is a critical factor in preventing bud rot, by reducing humid microclimates within your cannabis grow environment. These microclimates, pockets of stagnant, humid air, can persist even when you use dehumidifiers, creating local conditions favorable for mold growth. So, air circulation is the key to optimal microclimate management.

DryGair dehumidifiers come equipped with a patented 360° air circulation system designed to evenly distribute airflow throughout your greenhouse or grow room. This innovative airflow approach ensures uniform temperature and humidity levels, eliminating hotspots where bud rot is likely to develop.

By maintaining consistent air movement, growers can not only prevent mold but also optimize plant transpiration and nutrient uptake, resulting in healthier plants and higher yields. Combined with moisture management, effective air circulation offers a comprehensive solution to environmental mold management in cannabis production.

How SafriCanna Solved Their Mold Problem Using DryGair

SafriCanna is a GMP-certified medicinal cannabis producer in South Africa. The company utilizes DryGair’s DG-12 dehumidifiers to prevent mold outbreaks, which have been an issue prior to their installation.

In an interview with SafriCanna’s Master Grower, Chad Esch, he mentions, “We invested in DryGair mainly because we had issues with humidity. Because of the sizes of our flower rooms and the number of plants we have, there was an excess in the amount of moisture. If you can’t manage humidity during the evening, you’ll have a lot of issues with mold.”

The mold problems SafriCanna experienced were significantly reduced. “Since using DryGair we’ve seen amazing improvements to our product quality and yield. We’ve been able to reduce the number of molds. At the end of the day, we extract a lot more flower from the rooms than we used to.” Says Esch.

Additional Preventative Measures for Bud Rot

Preventing bud rot by controlling your greenhouse or grow room climate is the most effective option.

However, there are several other measures and practices you can use to help prevent bud rot and its symptoms.

Avoid Water Presence

Free water presence is necessary for bud rot development. So, besides dehumidification, you should prevent any water presence in your greenhouse or grow room.

Common methods to prevent water presence include – irrigating the soil directly (without splashing), using proper drainage beneath the growing pots, bags, or trays, and ensuring a drip-free irrigation piping system, if relevant.

Remove Injured or Infected Plants

Maintaing good plant health can have a huge impact on bud rot prevention.

Botrytis often infiltrates plants through wounds. So, making sure your plants are uninjured can help prevent bud rot infections in the first place.

Additionally, there’s a short period between the appearance of symptoms and full-blown spore development. So you may be able to prevent the spread of bud rot by simply removing plants that show early signs of mold.

Proper Plant Spacing

Placing your cannabis plants further away from each other allows more air to pass through, reducing the likelihood of humid microclimates developing in your greenhouse.

This can play a significant role in preventing bud rot outbreaks, as well as other molds from developing.

Use Neem Oil Preventatively

Neem oil is commonly used in horticulture to combat or prevent molds and other diseases. This oil, extracted from the neem tree, native to India, contains natural fungicidal materials.

You can use neem oil as a preventative measure, if you suspect a bud rot outbreak is starting in your greenhouse or grow room.

Summary of Bud Rot Prevention Measures:

• Dehumidification
• Air Circulation
• Preventing Free Water Presence
• Removing Injured or Infected Plants
• Proper Plant Spacing
• Preventative Neem Oil Use

Need a solution to mold in your grow? DryGair provides the leading dehumidification systems for cannabis production. Contact us for a tailored humidity solution!