WHAT IS INTEGRATED PEST MANAGEMENT?
"Integrated Pest Management (aka “IPM”) is an ecosystem-based strategy that focuses on long-term prevention of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties." - University of California Agriculture and Natural Resources
Establishing an effective IPM is essential in order to have a clean and productive garden harvest after harvest. It is how you will make sure your plants will not have the opportunity to get overtaken by pests or molds. This will require you to identify all potential threats and their different stages of life, along with how to prevent them, and how to get rid of them if it does get to that point.
HOW DO PEST AFFECT PLANTS?
Pests can negatively affect the plants in many different ways but the biggest problem is how pests can affect the health of the plants. This can drastically slow the rate of growth, reduce the yields, get stuck in the flowers (nobody ever is happy to find bugs in their cannabis), and even kill the plants entirely.
A large amount of grower’s time should be dedicated to scouting for pests, monitoring pest population, and applying pesticides or fungicides. All which will take time away from your typical day to day, it will take a lot of hard work to make sure the plants still receive the same amount of care.
Without proper planning you could wind up in a situation where the only way to get rid of your infestation is to get rid of everything and start over. This is heartbreaking, extremely labor intensive, not to mention--expensive.
COMMON PESTS IN CANNABIS CULTIVATIONS
There are a lot of pests in the world of agriculture, for cannabis it is no different. There are a some typical pests we tend to encounter:
THRIPS are a common pest to cannabis. Leaf damage looks similar to spider mite damage, but thrips poop more obviously-leaving little black spots--of poop!
Thrips will bite into the leaves of cannabis and suck out the nutrients, robbing the life from the plant. A bad thrip infestation can entirely prevent the plant from obtaining its essential nutrients. After they bite and suck out nutrients, there is an elongated mark left behind on the leaf that may have a shine to it, it can almost be like someone took a pencil and was tapping the lead end on the leaf.
With proper scouting over the plants, and a trained eye, they are very easy to identify as they will be crawling along on the tops of the leaves biting away. Thrips are generally easy to eliminate out of your garden, with common organic pesticides, or with beneficial predatory insects that seek out thrips as their food source.
Thrips lay their eggs on leaves, but nymphs can fall into the soil, so it is important to also treat the top of the soil when applying pesticides or beneficial insects.
SPIDER MITES are another common pest in the cannabis world. This pest is very small, and without proper knowledge of the signs to look for, they can easily get to large populations fast.
Spider mites hang out on the underside of the leaves, where they bite into the leaves and suck out nutrients. Spider mites leave behind a very small dot on the leaves; as they bite the leaf over and over they end up leaving behind quite a few small bite marks. If you see a grouping of small spots on your cannabis leaves that look abnormal, flip the leaf over to look for the very small mites moving around.
You can also use a jewelers scope to look for the very small spider mites, or even the batches of eggs they will lay. If you don't happen to catch the signs in time and you have a spider mite infestation, the spider mites will make a web to travel easier to and from food sources.
When webbing occurs, the infestation is severe, and will take extremely diligent action to eliminate the spider mites.
RUSSET MITES These pests are even smaller than spider mites, they don’t have wings, and they don’t produce any web. In order to be seen by the human eye, magnification is required. Russet mites also reproduce very quickly by laying eggs. This is why the russet mite is so dangerous to cannabis cultivators.
Russet mite damage usually starts at the bottom of the plant, with necrosis in the leaves that may look like a nutrient deficiency. You will also notice an extreme curling on the leaves. Russet mites latch onto the leaves, and suck out the vital nutrients from the plant. This will greatly slow down the growth of the plant, and largely reduce yields.
EXTREME CURLING OF LEAVES
Russet mites are a cause to go into “CODE RED” which will take a ton of effort and planning to get their populations down, and eventually eliminated.
POWDERY MILDEW Also known as PM, is a fungal disease that will look like white patches of mold on plant leaves, stems, and will also get into the flowers. Powdery mildew is caused by high humidity, and lack of airflow. It is very easy for PM spores to travel from plant to plant.
Healthy plants, environmental control, and proper pruning are keys to PM prevention. Because it is so easy to spread, very careful measures need to be taken to prevent cross contamination, and achieve eradication.
HOW CAN WE PRUNE FOR PEST CONTROL
Pruning is one of the most important tools in your IPM arsenal.
Proper pruning prevents hotspots where pests hide out and go unnoticed; it also helps to eliminate the micro-climates where you’re unaware humidity could be a potential issue. Removing plant matter from the inside of the plant will greatly improve your ability to physically see the entire plant. This will also allow airflow to pass over the entire surface area of the plant, reducing the risk of high humidity pockets.
Efficient pruning will also reduce the amount of time it takes to apply your spray, and increases the effectiveness of the spray. Eliminating the plant matter from the inside of the plant helps to ensure your spray is getting complete coverage of the plant.
Pests are not stupid.
The ones that survive the application will move shop to the untreated area of the plant and start rebuilding their populations. Without full coverage of a spray application, you’ll always be playing catch up.
Organic IPM tips to avoid pest infestation:
1) CLOTHING - Always make sure to be in a clean set of clothes each day when entering the garden, cleanliness is a really big factor.
2) PREDATORY INSECTS - Utilize beneficial predatory insects like green lacewing larvae and adults, minute pirate bugs, rove beetles, lady bugs, or beneficial nematodes.
3) ORGANIC ESSENTIAL OILS - Organic essential oils are a great to use as a preventative foliar spray, and are widely used as ingredients in some organic pesticides and fungicides. It is important to make sure the essential oil is organic, because of the fact that synthetic pesticides are widely used in agriculture, so you could potentially end up with those synthetic pesticides in your essential oil.
Organic Geranium essential oil has antifungal properties that can help prevent, and combat fungal disease like powdery mildew.
Organic essential clove oils also widely used as an organic pesticide. It has a very pungent smell that repels bugs, so you should only use this during the vegetative stage. Clove oil breaks down pest exoskeletons on contact, dehydrating the pests and killing them.
4) EXAMINE PLANTS CLOSELY, OFTEN - Pay close attention to your plants. Some pests are very, very small and so is the start of their damage. The earlier you can spot the signs of a pest or disease, the easier it is to correct that problem.
5) AVOID HUGE FLOWER ROOMS - A 250 light flower room, or having a 3000sqft veg room can look really impressive. But think about what it would look like to have a pest infestation or a disease. How realistic is it to control that space in a worst case scenario? In my experience, having more rooms that are smaller is a much more ideal way to deal with any potential pests or disease.