Indoor plant growers have always lived under the threat that infections and pests can quickly destroy an entire crop. Yet growers were hesitant to use commercial pesticides because of fears of residues on the smoke. This left them with few options and difficult choices. That has all changed in the last few, as federal government required re-registration of virtually all chemical pesticides. Many were dropped from registration and others were modified to meet stricter government guidelines. This shakeup spurred the development of innovations in pest control. “Integrated pest management” is the new buzzword fore those in the know.
Instead of relying on massive amounts of toxic chemicals, strategies now include physical disruption, fire, hormonal attractants and baits, companion planting, repellents and encapsulated baited poisons. Of more interest to indoor marijuana growers are technological developments using non-toxic, ecologically friendly chemicals, microorganisms and insects for plant protection. These products offer convenience and reliability in preventing and dealing with plant disease and pests. All of the products listed here can be used on fruit and vegetable crops and are compatible with organic gardens.
STERILIZERS
Organic and hydroponic growers both face the problem of replacing or cleaning the medium after each crop. Usually potting mixes and rockwool are replaced, while clay pebbles are washed. These measures are taken to prevent the cross-generational spread of disease. Some new products have been scaled down to give gardeners the same tools that were once only available only to large greenhouse growers. Several new chemicals used for greenhouse and grow room sterilization, pose less of an environmental or toxicity threat than pesticides or chlorine.
The Electric Soil Sterilizer holds a cubic foot (about 7.5 gallons) of soil or other planting medium. The unit works using heat controlled by a thermostat with a range of 100-200 degrees Fahrenheit. At 160 degrees Fahrenheit the material is pasteurized, which kills most harmful organisms, but not beneficials. Sterilization, which kills most organisms and weeds, occurs at 180 degrees. It takes about 30 minutes for sterilization to occur once loaded. It is rated at 500 watts or 4-1/2 amps, weighs 27 lbs. and costs $280 from Charley’s Greenhouse Supply. Phone: (800) 322-4707. Web site: www.charleysgreenhouse.com.
Physan 20 (TM) is a broad-spectrum disinfectant made from a salt, double quaternary ammonium chloride. It leaves no residue and breaks down into nitrogen, which plants use. It can be used a soil drench and to sterilize trays, walls and equipment. It can also be used to prevent seedling and plant diseases when it is placed into irrigation water. Physan 20 has been used for over 25 years and is considered very safe. It can be used in the same way as Zero-Tolerance (described below), and is excellent for clean-up between crops and irrigation water sterilization. Physan 20 can also be sprayed on plants to kill pathogens. A pint costs $12 from Maril Products, Inc., 620 South E St. Suite A, Tustin, CA 92780. Phone: (800) 546-7711.
Zero Tolerance (TM), is a sterilization approach to plant protection: rather than using friendly organisms as plant protectors, water and plant surfaces are kept pathogen-free by adding small amounts to all irrigation water. Zero Tolerance can be used as a one-time soil sterilizer or as an additive to keep water sterile. It is a solution of hydrogen superoxide (HO2), which is a very powerful oxidant. When this chemical comes in contact with insects, eggs, bacteria or viruses, it oxidizes them. Zero Tolerance can be used to wipe down trays, pots, walls or any other pathogen-containing surface. It sterilizes used soil and other planting mediums when used as a drench.
Zero Tolerance cannot be used with any of the biologicals mentioned below, but is a convenient substitute for bleach or hydrogen peroxide (H2O2) to sterilize equipment and media before planting. It takes about 2 days to degrade to water and oxygen.
It can be used in fog and misting systems to stop the spread of bud rot by killing the mold and spores. A little goes a long way; 2-1/2 gallons costs $110 from BioSafe Systems. Phone: (888) 273-3088. Web site: www.biosafesystems.com.
PEST CONTROLS
The pests that are most likely to attack marijuana indoors are aphids, fungus gnats, mites, thrips and whiteflies. Outdoor plants are subject to being munched on by rabbits, deer, rodents, caterpillars, slugs and snails, as well as attacked by insects. Organic growers have an arsenal of plant-pest predators and controls to choose from.
Aphids:
Aphids are prolific, 1/16 to 3/8 inch-long, pear-shaped insects. They come in many colors including white, green, pink, red, yellow and black. They mature in 7-10 days and start birthing live young. They suck the plant juices and are often herded by ants which milk them for the “honeydew” or sugar concentrate, which they release.
Aphidius colemani is a tiny non-social parasitic wasp that lays it eggs in living aphids. The adult wasp emerges from the aphid’s mummy in two weeks ready to mate and start laying eggs. It prefers temperatures below 80 degrees Fahrenheit. One introduction is all that is required. $24 + shipping from 1PM Labs. Phone: (315) 497-2063. Email: ipmiabs@baldcom.net.
Aphidoletes aphidimyza is a predatory midge. The midge lays about 250 eggs over a 10-day period near aphid colonies. The bright orange larvae, about 1/10” long, eat 10 aphids but attack many more. Then they pupate in the soil, emerge as adults and lay eggs. Predatory nematodes kill them and they don't do well in hydroponic mediums. The total cycle takes about three weeks. One release of 250 midges is enough to get the colony started. The insect goes dormant during flower-forcing with 12 or fewer light hours. 1PM ships the “ready to eat” midge larvae for $27 + shipping. Adults ready to lay eggs are available (250 predators cost $25) from Nature’s Control, P0 Box 35, Medford, OR 97501. Phone: (541) 899-8318. Email: bugsmc@teleport.com.
Aphidius matricariae is a small, parasitic wasp that lays eggs in aphid pupae. The adult wasp emerges from the mummified aphid and continues the cycle. Its life cycle is about three weeks. This insect does not provide total control but works well with aphid predators. Recommended use is one parasite per 3 sq. ft. One release will start the colony. Outdoors, the release rate is 5,000 per acre. Five hundred parasites cost $59 from Nature’s Control.
Gnats:
Fungus gnats are tiny black flies that hover near the planting medium. Their larvae feed on dead organic matter. They are vectors for plant diseases and should be eliminated from the indoor garden. There are several biological controls for this.
Gnatrol (TM) is a strain of bacillus thuringiensis that attacks only fungus gnats. The bacteria are mixed in water and applied to the medium three times weekly. It kills the larvae, so the gnats are eliminated over several weeks, as the adult population dies off. $39 + shipping from 1PM Labs.
Nemasys (TM) is a strain of predatory nematodes, which attack gnat in the larval stage. One pack of 50 million nematodes covers an area of 3,600 sq. ft. The nematodes should be introduced weekly for three consecutive weeks to eliminate infections. Contact Bioscape, Inc., 4381 Bodega Ave. Petaluma, CA 94952. Phone: (707) 781-9233. Web site: www.bioscape.com.
Scanmask (TM) is Steinernema feltros, a hybrid strain of nematodes, which uses chemical cues to find its prey. The nematodes enter the gnat and release bacteria that kill it. The nematode feasts on the multiplying bacteria. It is available as a spray that can be watered into the medium or as a granular that can be mixed in medium. One application is all that is needed, as the nematodes are persistent. $29 + shipping from IPM Labs.
Spider Mites:
To destroy spider mites, Stethorus punctillum is a type of tiny ladybug that eats both eggs and hatched spider mites. Each bug eats about 40 mites a day and many more eggs. About 100 bugs are needed to get a colony going. 100 bugs cost $67 from Nature’s Control.
Snails and Slugs:
Snails and slugs can be controlled using Sluggo, a new environmentally friendly blend of bait and iron phosphate. The snails are attracted to the bait. They stop feeding immediately and die within a few days. The active ingredient, iron phosphate, decomposes naturally in the soil. Two lbs., enough for about 5,000 sq. ft., cost $90 from Bioscape, Inc.
Thirps:
Thrips are plant feeders that feed on leaves, leaving a trail of damaged tissue and fecal matter. They are so small that they can barely be seen by the naked eye. They mature after seven to 10 days and lay 200 to 250 eggs, so the population increases quickly. The larvae feed on leaves.
Onus insidiosus, the minute pirate bug, is a small insect that pierces thrips with its mouth and sucks out their liquids. They reproduce quickly—every 10 to 20 days—and rapidly decimate the adult population. Available from IPM Labs and Nature’s Control.
Whiteflies:
Whiteflies are tiny (about 1/32” long), four-winged, white-colored flies that are easily seen fluttering about disturbed vegetation. Whiteflies have four distinct stages: the egg, crawler, which settles down to become immobile scale, which goes through several states before maturing as the whitefly. After about three weeks, the adult whitefly emerges, ready to eat and start laying eggs. At all stages, whiteflies feed by sucking plant juices, which slows plant growth and attracts disease.
Encarsia formosa is a tiny non-social wasp which feeds only on whiteflies. The adult female feeds on whitefly scales and lays hundreds of eggs, each one killing a whitefly scale. These wasps are very effective, but go into dormancy under a forcing regimen. Three to six weekly introductions are suggested at first sign of infection. $15 per 1,000 from 1PM Labs and Nature’s Control.
Deiphastus pusillus is a tiny (1/32” long) black ladybug that eats whiteflies at all stages of development. Each beetle eats 10 scales or 150 eggs daily, quickly controlling the whitefly population. Only one introduction should be required. Available from IPM Labs and Nature’s Control.
Nature’s Control also sells two kinds of predatory nematodes, Steinernema fehiae and Heterorhabditis heliothedis, both species of tiny worms. They attack and kill almost all soil-dwelling insects. The company recommends reinoculation every 6 weeks, but they usually eliminate the problem so that no reintroductions are needed. One million of the worms, which are shipped on a sponge, treat up to 2,500 sq. ft. They are rinsed into water from the sponge and then sprayed, watered or irrigated into the medium. One million nematodes cost $16.
Herbivores:
Deer, rabbits and other herbivores can be a vexing problem for outdoor gardeners. During early spring, when there is little vegetation available, young plants are especially vulnerable. In addition, some predators develop a taste for marijuana and its high. Keeping these predators away can be a daunting task.
In a four-year study at Rutgers University, researchers found that Deer Off was the most effective preparation at deterring deer. An added benefit is that the product also deters squirrels and rabbits. The product is EPA-approved and is appraised by environmentalists. The spray uses two deterrents, smell and taste. It is made from eggs, hot pepper and garlic. It is safe for both humans and pets and is environmentally friendly. An application lasts several months and cannot be washed away by rain. A pint bottle of ready-to-use spray costs $10 from Deer Off, Inc., 1127 High Ridge Rd., Suite 204, Stamford, CT 06905. Phone: (800) 333-7633. Web site: www.deer-off.com.
BETTER GROWTH AND DISEASE PROTECTION
Gardeners have an arsenal of friendly microbes they can use to protect their crops from pests and disease. These organisms use plant pests as their food source, but their diet does not include larger organisms so they are completely harmless to humans and animals. Many of these products are used to prevent disease rather than cure it. Their presence acts somewhat like a vaccine: they attack invading disease organisms without harming those that are helpful to plants. The organisms below are all registered for vegetable use and are a pure form of organics: using living organisms to keep other organisms under control.
Bio-Plex (TM) is a liquid biostimulant consisting of vitamins, enzymes, hormones, micronutrients and growth regulators. It encourages root growth and plant vigor. Its combination of ingredients include a ferment of fish and kelp, cold processed kelp, humic acids, chelated iron and zinc, and a soil and tissue penetrant. The manufacturer claims that this is a superior product because the penetrant allows nutrients to be absorbed more easily and quickly by plants, making them more resistant to stress and disease, requiring less fertilizer, and creating an environment at the root level that encourages the growth of beneficial microbes. One gallon goes a long way and costs $120 from Turf Chemicals Plus, Inc., 2213 Huber Dr., Manheim, PA 17545. Phone: (800) 441-3573.
Eco Sane (TM) is an “enzymic activated stabilized biologic catalyst.” It promotes increased plant growth and yield, as well increased tolerance to stress, especially in cold conditions. It has increased production on many crops from 20 to 500 percent when used every 2 to 4 weeks. It works directly on the plant and also promotes beneficial microorganisms. Use one ounce in two or three gallons of water for every 1,000 sq. ft. One gallon is $42.50 from The EKMA (TM) Companies, POB 560186, Miami, FL 33256. Phone: (305) 256-5456. Fax: (305) 256-0689.
Maxicrop is a product made from ascophyllum nodosum, Norwegian kelp. Kelp contains large amounts of trace elements, as well as hormones, enzymes and sugars, which stimulate plant growth and health. In addition to working on the plant directly, kelp encourages beneficial microbial life. Supplementation with Maxicrop results in stronger plants more resistant to stress. The enzymes encourage stronger root growth and more vigorous leaf growth. The supplement is added to the water periodically. One gallon of liquid costs $16. Powder (10.7 oz.), which makes 1 gallon of liquid, costs $13. Available from Maxicrop, U.S.A., Inc., POB 964, Arlington Heights, IL 60006. Phone: (800) 535-7964. Web site: www.maxicrop.com.
Mycor Flower Saver (TM) is a mixture of four strains of vesicular-arbuscular mycorrhizal fungi and growth-promoting bacteria with organic biostimulants. The fungi develop a symbiotic relationship with the roots, providing them with nutrients in return for sugars produced by the plant. This relationship promotes faster growth and enhanced resistance to stress and pathogens. The dry powder is mixed into the medium at the rate of 3 lbs. per 100 sq. ft. at planting. It can be used indoors or out. A six-pound box costs $40 from Plant Health Care, Inc., 440 William Pitt Way, Pittsburg, PA 15238. Phone: (800) 421-9051. Web site: www.planthealthcare.com.
PHC Biopak (TM) is a biostimulant containing several strains of bacteria that live in symbiosis with the plant roots. PHC Biopak promotes fast root development (which increases plant growth and uptake of fertilizer), increases bioactivity in the medium and reduces plant susceptibility to disease. A one-pound jar costs $25 from Plant Health Care.
PHC Healthy Start (TM) 3-4-3 is derived from bone, blood and kelp meal, rice bran and other natural fertilizers. The formula, 3-4-3, is a good mix for start-ups and clones as it promotes rooting. The natural ingredients provide complete micronutrients for soil and soilless media. What makes this blend truly unique is the addition of nitrogen and phosphorous-dissolving bacteria, which release nutrients to the roots as needed. Humic acid in the form of leonardite, a mined mineral, is added to encourage growth of beneficial microbes. As a result, plants require less fertilizer and are less likely to suffer from nutrient deficiencies. Twenty-five pounds treats about 250 sq. ft. One treatment per crop is needed, indoors or outdoors. A 25-lb. bag costs $15 from Plant Health Care.
RootShield is a biological fungicide that protects roots from pythium, rhizoctonia and fusarium—fungi that cause root and stem rot as well as die-off in seedlings and clones. The fungus in RootShield quickly forms a barrier against pathogens and attacks pathogens trying to break through. One application is all that is needed to “infect” the roots with this symbiotic organism, which feeds on nutrients secreted by the root system. RootShield comes as a dry powder that is mixed with water and applied as a drench at the rate of 6 oz. per cubic yard of medium or as a granular for dry-dipping cuttings. It is sometimes mixed into the planting medium at the rate of 1 lb. per cubic yard. The active ingredient is Trichoderma harzanum strain T-22, developed at Cornell University. It is recommended for vegetables and is non-toxic to humans, birds and other animals and safe to use around water sources. A one-pound bag costs about $37. It is not available from retailers but is sold by wholesalers, such as McCalif, (800) 234-4559. For other suppliers, contact the manufacturer, BioWorks, Inc. Phone: (800) 877-9443. Web site: www.bioworksbiocontrol.com.
Roots Transplant 1-STEP is an enhanced 2-2-2 transplanting fertilizer. In addition to nutrients it contains 13 species of mycorrhizae, which colonize the roots and develop symbiotic relationships with them. Together they increase fertilizer absorption, bioactivity and resistance to disease. In addition, the powder contains a biostimulant to promote root growth and a water-holding gel to increase water retention. One pound treats about 250 six inch or 125 ten inch containers. Treat plants every 2 to 4 weeks. 25 lbs. cost $23 from Roots Inc., 3120 Weatherford Rd., Independence, MO 64055. Phone: (800) 342-6173.