PESTICIDES: Characteristics and Dangers

Ailments Orchid Doctor

by Robert M. [Bert] Hamilton (Compiler)

Originally published in The Orchid Doctor in 1980 and 1988

Posted by Sys Admin almost 8 years ago.

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A recent review of them from the orchidist's viewpoint and requirements, with an LD50 list; refer to AU80-25+
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Pesticides Comments
PESTICIDES: Application Safeguards They are all toxic so beware of them; wear protective clothing and a face-mask because ordinary clothing absorbs the spray; notify someone outside the greenhouse that you going to spray; always shower after; spray only in the morning when it is cooler; spray outdoors only on a calm day; re-enter a closed sprayed area only after the toxic has been dispersed; the spray residue builds up on leaf surfaces, so wash your hands every time you handle a plant; promise? F087-126 0
PESTICIDES: Applicator's Licence A restricted pesticide applicatorf s licence can be obtained by anyone who buys the government pesticides manual and passes an exam after taking a course given by Agriculture agents; the manual alone is well worth the price. F087-126 0
PESTICIDES: Available Only to Commercial Nurseries Agricultural chemicals are strictly regulated and their availability is usually restricted before being made available as a consumer package, and it may be delayed for years; repackaging into smaller packages is illegal, so you can't easily buy a few dollars worth, except from a brother. F83-155 0
PESTICIDES: Chemicals For a list of those used in plant disease control, with both common and chemical names, their Lethai Dose-50 rating and their use as either systemics, fungicides, disinfectants, bactericides, algicides, germicides or nematocides; refer to OBIV-266 0
PESTICIDES: Classification Chemical relationships: Organo-phosphates: Parathion, TEPP, Sulfotepp, Dibron, Systox, Metasystox-R, Thimet, Cygon, Diazinon, Ethion, Malathion, Vapona; 2: Chlorinated hydrocarbons: Chlorobenzilate, Kelthane, Dimite; 3: Sulfenones: Tedion, Ovex, Genite; 4: Sulfites: Aramite, Omite; 5: Cyclic carbonates: Morestan; 6: Pentac; 7: Carbamates: Zectran, Mesurol, Temik. A70-948; OWD 0
PESTICIDES: Compatibility Mixing of two brands is often done but combinations may injure plants where each singly does not; mix powders with powders, E.C's. with E.C's., always in the same class of pesticide. AH86-66 0
PESTICIDES: Compatibility Charts Charts of pesticides that can be mixed before applying have been published; two addresses given; Kelthane and Malathion are compatible. A69-793 0
PESTICIDES: Data and Conduct Explanation of all the terms for 11 fungicides used on orchids; 23 insecticides with trade names and toxicity ratings; for details refer to NZ86-47; for classification of them see OA82-113 0
PESTICIDES: Excessive Uses A preventive spraying program leads to phytotoxicity in the plants. A76-698 0
PESTICIDES: For Home Use Use fungus control materials not essentially dangerous but designed to eliminate insects, such as Malathion, Kelthane, Diazinon and Pentac, all safe to use but be sure to ventilate the premises, minimize contact, and wash up after. A82-1061 0
PESTICIDES: Frequency of Spraying Depends on the product: Benlate can be applied every two weeks until the fungus is controlled in two or three applications; pesticides generally can be applied every three or four weeks until control is achieved. A82-1178 0
PESTICIDES: Injury to Plants Use them with great caution; observe precautions regarding temperatures at which to apply, frequency of application and rates and compatibility; they can cause leaf-scorch, necrotic spotting, abnormal pigmentation. AH53 0
PESTICIDES: Kocide and Zyban New names, they should first be checked to see if they have been cleared for orchids at your local Agriculture Department level; recommendations are the same rates for both Kocide 101 and Zyban 15%: 1.5 pounds of the WP per 100 gallons of water. A85-611 0
PESTICIDES: Lethal Dose The "LD50" means the amount of the chemical that will obtain a 50% kill of warm-blooded animals with a single dose; the dose is given in milligrams of chemical per kilogram of body weight. A71-893 0
PESTICIDES: Non-use Some good growers rarely use them; they rely on good culture, with pest-free results. A76-698 0
PESTICIDES: Phytotoxicity It appears in five ways: as burn, on leaf tip, on leaf margin, on leaf surface, or bud; as necrosis, which is similar to burn; chlorosis which is a yellowing or bleaching effect, such as spotting tip yellowing, or failure of the whole leaf; leaf distortion, such as curling, crinkling or cupping; and, stunting. AH86-66 0
PESTICIDES: Plants Newly Introduced Into Greenhouse All should be sprayed; recommended: Isotox plant spray which is as good as any, or Diazinon 50%WP. A78-403 0
PESTICIDES: Poisonous So many are deadly; for a list of substances with LD50 rate and notes, refer to N314 0
PESTICIDES: Pots Brought Into Growing Area Pots brought into a roofed slathouse should be treated with granules such as metaldehyde and mesurol; spread them over and around the pots. A78-403 0
PESTICIDES: Prophylactic Use A mix of Natriphene, fertilizer and water every morning on plants is not recommended; don't over-do a good thing. A86-1033 0
PESTICIDES: Recommended Names For a list of 22 substances usually used in greenhouses, with their LD50 rating, and useful notes, refer to N314 0
PESTICIDES: Registration for Use on Orchids Many standards are not registered: Truban (ethazol), Subdue 2E (metalaxyl) and Physan (n-alkyl ammonium chlorides) are three frequently recommended and widely used; a petition is recommended to get them recognized by the authorities. A86-915 0
PESTICIDES: Regular Use A regular programme of applying pesticides is not beneficial to the plants, except in moderation. A78-112 0
PESTICIDES: Review Safety ratings, label warning statements; toxicity table of the most popular formulations; their availibility; a compatibility table of 22 kinds; their application; storage, shelf life, etc.; refer to AH104+ 0
PESTICIDES: Rules for Application Identify the right insect or disease; use the recommended insecticide; use it at the right amount, in the right way and at the right time. AH86-64 0
PESTICIDES: Safe Use of Dangerous Materials For a long list of the do 1 s and don'ts refer to AU87(3)-45 0
PESTICIDES: Shelf Deterioration Benlate remains effective in storage for two years but a solution of it must be used in eight hours, if left for 24 hours it becomes harmful to plants and not insects; Di-Systox lasts two years on shelf, Meta-Systox lasts two years also, Captan three years,and Malathion lasts indefinitely. AU84-102 0
PESTICIDES: Shelf Life They should be purchased for short-term use; mark the date of purchase on the container; most keep their effectiveness for two or more years if stpred properly; signs of ineffectiveness in dusts and powders: lumping, and hard to suspend in water; emulsions or oil sprays: sludge forms or they have no milky appearance when water is added. C71-64 0
PESTICIDES: Storage Emulsifiable concentrates and most liquids should be stored above freezing; if properly sealed they should remain effective for two years; do not use if the emulsifiable concentrate does not turn "milky" when water is added or if they develop an insoluble sludge. AH109 0
PESTICIDES: Stored for Use Both fungicides and insecticides deteriorate rapidly when stored in dilute solution with water. A67-901 0
PESTICIDES: Systemic Types Mixing them together; there is only one true systemic and that is the fungicide Benlate or benomyl; Cygon is only somewhat systemic; a good possibility they can be mixed; so far, no systemic insecticide or miticide has been approved for use on orchids. A74-595 0
PESTICIDES: Temperatures At Which it Is Hazardous for Humans to Work with Them Above 85 deg.F. in the afternoon it is best not to work with them. OD75-162 0
PESTICIDES: Toxicity Ratings For a list of pesticides in Australia, many of whi ch have strange trade names for common brands elsewhere, refer to AU87(3)-46 0
PESTICIDES: Toxicity to Humans For a table with generic and trade names, their toxicity class, Lethal-Dose/50 data, acute dermal and inhalation toxici ties for 18 common brands, refer to AH86-66 0
PESTICIDES: Types Included in the Word Algacides, biological pesticides, fungicides, herbacides, insecticides, molluscicides (snail baits) and rodenticides; many of these names are entered in this book. AU87(3)-45; RMH 0
PESTICIDES: Vulnerable Parts of the Human Body All parts; the most vulnerable are: the skin, particularly of the scrotum, the upper legs and the lower trunk area; one drop or two of a common organophosphate such as parathion, sulfotepp, etc., on the body is very dangerous; wear a rubber apron. OD75-162; malathion not as bad. OWD 0

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