SODIUM SELENATE. A poison which can be applied to the soil and taken
up by the plant, controlling mites, particularly red spider on car
nation in greenhouses, cyclamen mite in pot plants, and leaf nematodes
in outdoor chrysanthemum. The dosage must be carefully figured; 1 gram
dissolved in 1 gallon of water will treat 4 square feet of soil surface.
Capsules (see Kapsulate) can be used for pot plants. A dry mixture,
P-40, contains 2% sodium selenate, can be broadcast at rate of 3 pounds
to 100 square feet. Sodium selenate is very toxic to man; never use it on
soil that may grow vegetables in the next couple of years. It is also toxic
to plants; the dosage should not be increased, nor the treatment repeated
within 4 to 6 months.
Spergon (chloranil, U. S. Rubber Co., Naugatuck Chemical Div., Nau
SULFUR, primarily a fungicide but sometimes used to kill mites and in
the form of lime sulfur for scale insects. Sulfur is used as a dust,
fine enough to pass through a 300-mesh sieve, or as a spray prepared from
wettable powder, to control brown rot, apple scab, and other fruit
diseases, powdery mildews, rusts, rose black spot. It is injurious to some
cucurbits and should not be used on melons and cucumbers, and it may
injure any plant in very hot weather, but in general it is safe and effec
Systox (trialkyl thiophosphate, Pittsburgh Agric. Chem. Co., Div. of
Pittsburgh Coke & Chemical Co., 350 Fifth Ave., New York, N.Y.).
Another systemic insecticide, poisonous to man like other phosphates and
still experimental as far as the home garden is concerned.
Tersan (thiram, E. I. du Pont de Nemours & Co., Wilmington, Del.).
Used as a turf fungicide, good for snowmold at 6 ounces per 1000
square feet, and also for onion smut.
TETRAETHYL PYROPHOSPHATE, TEPP. Another phosphate insecticide, as toxic
to man as parathion, very effective in control of aphids, 17-year
locust, mites, some mealybugs and whiteflies. There is no residual effect
so it can be used for aphids even on such food plants as broccoli. It is
said to be the only insecticide effective against adults of 17-year locust.
THIRAM (tetramethyl thiuram disulfide). See Arasan, Tersan.
THIOLUTIN. An antibiotic that reduces the incidence of fire blight when
applied to fruit trees in the blossom stage.
TOXAPHENE (chlorinated camphene). To date this has been used mostly
in control of cotton pests and for grasshoppers, but it is also effec
tive for thrips, spittle bugs, and some other insects.