Post by Ask Jan on Dec 6, 2011 13:53:20 GMT -8
Synthetic Chemicals—never use on medical marijuana!
Synthetic pesticides were first used in 1892. They run the gamut from naturally occurring pyrethroids to mutant DDT.
No pesticides have been labeled in the USA for use on Cannabis. European hemp researchers have tested many synthetic chemicals on fiber crops. Synthetic chemicals should not be used on crops destined for human consumption, like seed oil or medical marijuana. I know Ed Rosenthal recommended spraying marijuana with a product called “Wilt-Pruf” to suffocate spider mites. “Wilt-Pruf’s” generic name is polyvinyl chloride, the same as Saran Wrap. Not a good idea to smoke that stuff!
Chemical toxicity depends on set and setting. Many synthetic chemicals are systemic. Systemics are particularly dangerous on plants destined for human consumption. The poisons remain in plant tissues without breaking down.
Many new pesticides are desirable because they are very selective. They kill pests while sparing beneficial organisms. Many selective pesticides are used on hops and tobacco in the United States. Hops are related to Cannabis so collected data is applicable to marijuana.
Placing synthetics in baited traps is a relatively safe application of pesticides. Baited traps keep the chemicals off plants, and keep the chemicals containerized for easy disposal. Using synthetics for seed treatments (coating seeds with pesticides before planting) is relatively safe. Very little pesticide is introduced into the environment.
Pesticides come in a variety of formulations: aerosols, baits, dusts, emulsifiable concentrates, flowable concentrates, fumigants, granules, slow release, soluable powders and wettable powders. The amount of active ingredient in solid formulations is presented as a percentage of weight. Example, 50 % wettable powder (WP) contains 50 % active ingredient. The remaining 50 % is made up of “inactive ingredients.” Liquid formulations are expressed as either a percentage of weight or as the number of pounds active ingredient per gallon of product. Example, 4 lb/gal emulsifying concentrates (EC) contains 4 pounds of an active ingredient per gallon, which equals roughly 45 % EC.
Synthetic pesticides are classified by their chemical structures. The major groups include chlorinated hydrocarbons, organophosphates, carbamates, dipyridilium herbicides, and the most popular group, “miscellaneous.”
Synthetic pyrethroids and synthetic pheromones are considered “biorational.”
To stay out of trouble, “never do two stupid things at the same time.” Frank LeCase
1. Hemp Diseases and Pests, Management and Biological Control. J. M. McPartland, R. C. Clarke and D. P. Watson.