Look closely at all openings in your grow room—doors, vent holes, electrical outlets, duct shafts, windows, wall air conditioners and the space underneath the door. Any opening can be a vector for miniature thieves who steal your crops. Seal or screen all openings to close the way in.
Next, analyze your attic space, crawl space and flooring issues. Attics might be stuffed with old insulation that breeds all sorts of nasty fungi, as well as rats, squirrels, possums or other larger animals. Flooring material can be wet or otherwise sullied. Carpets are a great place for plant-harming organisms to thrive.
When I moved to an old house, I found attic insulation soaked with rat urine and piled high with feces. Oddly enough, I couldn’t detect the pungent odor of this tainted attic inside the house itself. I paid a guy to bring his industrial vacuum cleaner to suck the old insulation out of the attic. Then I sprayed the attic with a microbial-killing solution. After that, I sprayed it with boric acid (a natural way to kill cockroaches, termites and other pests). I then had 36 inches of specially made sterile insulation installed. The benefits from this work included saving energy and preventing infrared heat loss. This kind of obsessive attention to cleanliness and energy efficiency is a hallmark of professional hydroponics growing.
Next, take a look at your wall coverings. Many growers hang reflective materials on their walls. That’s smart, because they reflect light back onto your plants. But I’ve seen people remove their reflective materials only to find ugly mats of fungi or molds underneath. If your room has high humidity, wall coverings are a great breeding ground for such intruders.
Any vent, tube or duct that brings air into your room should be inspected. Whenever possible, put a protective filter in-line or on the opening to any vent or duct that transfers air into your room. You should also have an in-room filtering mechanism that scrubs your air. Try Can-Filter, Active Air and Phresh filters; they’re favorites with Rosebud readers.
Along with armoring your room using filtration, caulking, cleaning, new materials and inspection, also pay close attention to any objects, tools or organic matter that come into your grow room. Picture those clean rooms where computer microchips are made. Before entering, you might be required to shower with antimicrobial soap and put on a sterile suit and gloves. Some of those rooms even have an air lock that further isolates the interior of the clean room from the real world. You don’t have to go that far with your hydroponics grow room protection protocols; however, one good practice, if you are buying clones, is to use a magnifying glass to examine each one before you bring it into your room, since clones are a known vector for insects and pathogens.
Of course, the best protection against clones introducing pests or pathogens into your garden is to grow mothers from seed and do your own cloning, but it is tempting to buy externally produced clones to save time. In my experience, about 30% of commercially available clones are contaminated with mites, gnats, thrips, aphids, root diseases or other pathogens. How can you tell? If the clone has healthy leaves and stems and the roots are light-colored and dense, it’s likely that the clone doesn’t have a root disease. Close examination of stems and leaves will indicate whether the clone has pests or pathogens above ground.
Even if you don’t see evidence of contaminants, it’s a good idea to use a clone quarantine chamber for your externally sourced clones. Keep them there for a week or two before you integrate them into your grow room. During quarantine, you’ll observe leaves, stems and roots, as well as growth rate and vigor, to determine for sure if the clones are healthy. If they’re not, don’t bring them into your grow room. And if you’ve had any physical contact with infected plants, change your clothes and take a shower before going back into contact with healthy plants.
Another preventative measure for your grow room is to inspect anything that touches your plants’ roots. Obviously, water quality is of utmost importance. Many water supplies carry organisms or materials that aren’t good for your plants. If you’re not certain that your water supply is pristine, use reverse osmosis, such as the Stealth 200 RO system. Unless you’re using pure aeroponics or NFT with zero root-zone material, you also have rock wool, Hydroton, perlite, soil mix or some other material around your roots. If you use soil mixes, coconut coir, peat and compost, you need to examine materials closely. There are many credible reports of dangerous pests and pathogens living in organic materials, even ones you buy bagged at the garden store.
Protect your crop while enhancing root growth and nutrient uptake by using liquid beneficial bacteria, fungi and enzymes in your root zone. The beneficial fungi and bacteria armor your roots and assist their intake of moisture and nutrients. They also increase overall root mass and health. The enzymes break down organic materials into forms that can be taken in as nutrients. They also cleanse the root zone, making it a less attractive place for pathogens. Beneficial microbes in your root zone provide a barrier against harmful microbes.
Believe it or not, your plants can even be harmed by chemicals in tubing, plastics and grow chamber materials. Beginning about five years ago, growers started noticing deformed leaves, slow growth and in some cases plant death in their hydroponics operations. Researchers found that irrigation tubing and grow chambers were off-gassing or otherwise transferring toxins into their grow environments and their plants. The No. 1 culprit appeared to be a toxin called diisobutyl phthalate (DIBP), along with related toxins that are often used in plastics, vinyl and similar materials. Not only are these materials harmful to plants, they can also be harmful to humans. Whenever you’re purchasing a grow chamber, irrigation tubing or similar materials, be sure to ask the manufacturer about the presence and transferability of toxins in their products. Also check grower’s forums and ask at your hydroponics store.
Whether it’s pruners, pH meters, root-zone media, clones, pots, irrigation tubing, soil mixes, water or other things that can enter your grow room, your job is to inspect and screen so none of them transfer pests, pathogens or toxins into your valuable garden. If you’re using a sealed grow room and controlled-environment agriculture, or if you’ve followed the fortress-building advice we just gave you, you probably won’t have pests to deal with!
To Spray or Not to Spray
What if, despite all your precautions, you look in your grow room and see evidence of mites, thrips, aphids, fungus gnats or other bugs? If you’re in veg phase or very early bloom phase, you might get away with treating your plants with an all-natural foliar insecticidal soap, neem oil foliar solution, pyrethrum or diatomaceous earth (used as a powder to attack aphids). If you have fungus gnats, you might use Spinosad, which is a relatively safe liquid that kills gnats without harming you or your plants.
Some hydroponic growers borrow toxic ideas from industrial agriculture and use Avid, malathion, sulfur burners, and other polluting substances and methods to protect their crops. But when people consume the plants produced by these toxic gardens, they could well be ingesting poisons. My feeling is that these techniques are not acceptable in modern hydroponics gardens.
Some people make a distinction between systemic and topical pesticides, insecticides, fungicides and mildewcides. It’s true that some intervention materials don’t absorb into plant tissues. These non-systemics are theoretically less toxic than systemics that enter plant tissue and stay there. But it’s logical to say that if you spray or dust materials onto plants, especially once flowers have formed, those materials are going to be there at harvest time. And when you consume the crops, you’ll be consuming those materials too. The only way this wouldn’t be true would be if you use authentic non-systemic materials and then wash your crops before harvest. If humidity conditions allow it, I sometimes spray my crops with pure water a couple of weeks before harvest to wash off any contaminants from the air. However, I won’t do this if there’s risk of gray mold.
Some growers use baking soda or sulfur-lime dust mix to defeat powdery mildew. Again, wash your leaves off after the mildew is dead, unless you have dense flowers that are ripe for mold. In general, it’s not a good idea to spray or dust chemical poisons or so-called natural poisons like pyrethrum when you have flowering crops.
One pest-killing technique that doesn’t leave poisons or other residues on your crops relies on dosing your grow room atmosphere with extreme levels of CO2. This is especially appropriate if you have a CEA (controlled-environment agriculture) sealed room, but you can make it work in any reasonably well-sequestered grow space.
Your first step is to shut off all venting and be ready to put a towel at the base of the grow room door. You’re going to be upping your CO2 parts per million to 8,000 ppm for two hours. That much CO2 will exceed the range of your metering, dispensing and monitoring equipment. In most cases, you’ll be using a tank instead of a CO2 burner because only a tank can deliver that much gas that quickly. Remember to use extreme caution. A concentration of CO2 above 500 ppm isn’t healthy for humans. Keep your room closed tightly while the CO2 is increased, and stay out until the concentrations are back under 500 ppm.
This CO2 blast method will kill adult insect pests, but it won’t kill their eggs, so wait five days and repeat in order to catch hatchlings before they’re old enough to lay eggs of their own. To implement the CO2 blast, you’ll need to do some hardware experimentation before you can reliably inject that much CO2 that fast. Professional growers affirm that this method gets rid of pests, increases plant metabolism, and leaves your harvests clean and pest-free.
Using Helpful Insects to Control Hurtful Insects
Integrated pest management includes strategies that prevent pests from getting into your grow room and helps control them if they do get in. Using beneficial insects to get rid of harmful insects is an IPM fundamental. You can install beneficial insects before you notice any pests or after you detect an infestation.
Let’s say you detect spider mites halfway through a bloom phase. The intruders are likely two-spotted spider mites (Tetranychus urticae) or related pest mites. They build ugly webs and suck the life out of your plants. An ethical grower won’t spray poison or most anything else on their crops so close to harvest time. The solution? Get predator mites that eat bad mites and release them in your grow room.
Predator mites are an example of beneficial insects used by gardeners to eliminate pest insects. Many growers think that you install beneficial insects after you’ve got an infestation. But beneficial insects, especially the most useful kinds, such as ladybugs (Hippodamia convergens), can be installed in your room before any problems arise. Like hungry sentries, they’ll patrol your grow room and likely stop any pests before they get a foothold.
There is no one-size-fits-all formula when it comes to using beneficial insects. Some beneficials go dormant during the bloom cycle. The beneficial mite Phytoseiulus persimillis eats evil spider mites, but it prefers high humidity—something that shouldn’t be present in your grow room. That’s why a knowledgeable beneficial insects dealer will recommend that you install Phytoseiulus persimillis along with other types of beneficial insects such as G. occidentalis or N. californicus, so you get beneficial insects that work in the range of conditions found in hydroponics indoor gardens. With ladybugs, you want to over-install because they have a tendency to fly into your hot lights. There are many nuances to using beneficial insects, and you’ll find it’s fun to mix and match beneficials that will do the job for you.
It’s entertaining to sic your pet beneficials on the bad guys. A superstar is the minute pirate bug (Orius insidiosus). They eat caterpillars, aphids, thrips and mites. I recommend the book Insects and Gardens: In Pursuit of a Garden Ecology, by Eric Grissell. This book illustrates the interconnectedness of insects with each other and with plants.
In the end, it’s all about balancing your desire for a sterile, sanitary, pest-free, high-yielding grow room and the realities that living organisms are everywhere. Using poisons, you might eliminate all pests, but you also create a toxic crop. Using IPM and all the methods described here, pests might chomp 3% of your crop, but the remaining 97% will be clean and tasty, a great result for any serious grower.
IPM Inside You
The principles of IPM can work when applied to your personal health. When you take antibiotics, you risk killing all the beneficial organisms in your digestive tract that help you digest food. This can lead to digestive problems, including your body failing to ingest all the available nutrients in what you eat. To solve this, you can take more pharmaceuticals, or you can apply IPM concepts to your own body by re-introducing probiotic beneficial microbes found in yogurt and health supplements to restore the right microbes into your digestive tract. Just as with your hydroponics plants, the emphasis on balance and prevention means you want to try the most natural, safe and holistic solutions—whether we’re talking about spider mites or stomach cramps!
Assassin bug – Reduviidaye
The assassin bug feeds mainly on aphids, caterpillars, Colorado potato beetles, Japanese beetles, leafhoppers and Mexican bean beetles.
Damsel bug – Nabidae
The damsel bug feeds on aphids, leafhoppers, mites and caterpillars.
Big-eyed bug - Lygaeidae
Big-eyed bugs feed on aphids, caterpillar eggs and larvae, immature bugs, leafhoppers and spider mites.
Predacious stink bug – Pentatomidae
Predacious stink bugs feed on Colorado potato beetles and various caterpillar larvae.
Syrphid fly larvae – Syrphidae
Fly larvae of this species feed on aphids and mealybugs.
Lady beetle or Ladybug - Hippodamia convergens
The lady beetle feeds mainly on aphids and other soft-bodied insects such as mealybugs and spider mites.
Green lacewing larvae - Chrysopa camea
Lacewing larvae, known as aphid lions, feed on insect eggs, aphids, spider mites, thrips, leafhopper nymphs and small caterpillar larvae. Adult lacewings are not predacious.
Predatory mites - Phytoseiulus persimilus
Predatory mites and several other species feed on many mite pests, including the two-spotted spider mite. Be sure to combine predatory mites to get maximum effectiveness.
Trichogramma wasp – Trichogrammatidae
This tiny wasp attacks the eggs of more than 200 pest species, including cutworms, corn borers, corn earworms, armyworms, codling moths and cabbage moths. Release time is critical for their effectiveness since they only attack pest eggs.
Encarsia wasp – Encyrtidae
Whitefly is parasitized by this wasp.
Minute Pirate Bug - Orius insidiosus
Killer of mites, aphids, thrips and caterpillars.
© Copyright RosebudMag.com, 2012
To create link towards this article on your website,
copy and paste the text below in your page.
Monday, 03 December 2012