PRODUCTS ON THE SHELVES AND WHAT THEY DO FOR US

By Nancy Robitaille

Nursery and hardware shelves are full to the brim with chemicals for this problem or that insect. 

Safety precautions should be taken when using these poisons. Some are toxic to humans, some, less so. 

1. Mix only enough spray or drench for one application. 

2. Discard leftover chemical liquids in a safe place. This does not include the kitchen sink or the toilet since all water is collected, “sterilized” by chemicals and reused for our consumption. Probably one of the less noxious places to pour unwanted poisons is over shrubs outdoors that might have use for it. although this, too, will eventually get to our drinking water.

3. Chemicals, especially when mixed can evaporate when left for a time and thus become stronger than needed and this may harm your plants. 

4. Wear protective clothing when spraying. Chemicals which are sprayed may fall to the skin and enter the body. Carefully wash all exposed areas.

5. It is necessary to shake the chemicals while in the spray bottle so they do not settle making the top portion weaker than the bottom.

6. Use the correct spray or drench for the insect you are poisoning.

7. Containers used in mixing chemicals should not be used for any other purpose.

8. Store chemicals in a safe, protected place. Children and pets may become poisoned with them.

9. Any unused or empty containers of chemicals should be disposed of in a safe manner.

HOW CHEMICAL POISONS ACT WITH INSECTS:

Three types of poisons are available for the eradication of insects. One is the stomach poisons that are sprayed on plants and act when insects eat the foliage. The second is Contact insecticides which destroy insects by touching the adult or newly hatched insects, larvae and eggs. Kelthane, Malathion 50 and Lindane (may no longer be available) are examples, some having both effects. All three give a fast kill and may serve as preventatives if regularly applied. The third type of insecticide is Systemic which is slower but the effect lasts longer.

No Pest Strips may help eliminate aphids, whiteflies, mealy bugs (foliar), thrips and other insects when placed inside a plastic bag with a tray of plants. (Strip should not touch plant.) Raid House and Garden Bug Killer is also safe with African violets and easy to use.

CHEMICALS:

BENOMYL: (BENLATE). Use on botrytis blight, crown rot, powdery mildew

CAPTAN: (Orthocide, Captan) Use on Crown rot and powdery mildew

Cygon 2E Systemic: May be difficult to find. One-half teaspoon to gallon water.

DICOFOL: (KELTHANE) Use on cyclamen mite, broad mite, spider mite. This is moderately toxic to humans. One to one-and-a half teaspoons to a gallon water.

DIMETHOATE: (CYGON) Use for Root nematodes, foliar mealy bugs, black flies (fungus gnats), aphids and mites

FERBAM: (FERBAM) Crown rot, powdery mildew. Not toxic to humans. Ferbam can stain leaves and flowers. Use Captan or benomyl instead.

MALATHION: (CYTHION) Aphids, foliar mealy bugs, whiteflies. Low toxicity to humans.

SULFER: (SULFER) Crown rot, mildew. A well-known fungicide.

Marathon—Mealy bugs. One-eighth to one-quarter teaspoon to a 2-3 inch pot

PHYSAN: Controls African violet pathogens, algae on mats, wicks, reservoirs, trays, pots, benches and work surfaces. Controls damping off on seedlings and plants. Controls crown rot, powdery mildew, botrytis. Disinfects tools.

Avid: mites

Neem Oil: (Dyna Grow) Thrips, foliar mealy bugs—makes a plant unpalatable to insects and they starve.

Fungicide 3: (contains Neem)

RID: (LICE TREATMENT SHAMPOO) Home-made remedy. Effective against spider mites and thrips. One teaspoon to a quart of water.

SAFER’S END-ALL: MITICIDE/INSECTICIDE/ACARICIDE
Kills all stages of Aphids, mites and whitefly, spider mites, spittle bugs, adult and nymph stages of thrips, flea beetles, caterpillars, mealy bugs, scale insects and sugar ants.
20ml concentrate with one liter water

Milk: (Home-made remedy) Diluted milk may be painted onto powdery mildew.

Cinnamon: (Home-made remedy) May be dusted onto powdery mildew. Cinnamon is not easy to clean off leaves.

INSECTS:

APHIDS: Green, red, pink, black, brown, purple or white, winged and wingless, one-sixteenth to one-eighth inch long. Bodies are round to pear shaped. Insects have long legs and antennae. They may be found on new growing tips and under leaves. Aphids are sucking insects. Foliage and new growth may turn pale, curl up and die. Aphids leave secretions of honeydew which may host SOOTY MOLD, a black fungus.

Treatment: Remove insects with your fingers or apply alcohol to a cotton swab and touch each. Wash leaves with water after treatment with alcohol. 

For heavy infestation spray with malathion, one teaspoon to one gallon water or use orthene, follow directions on package. Repeat every 5 to 7 days until Aphids have been eliminated. Science Systemic is also recommended although this product may be hard to find.

OR: Drench each pot with a solution containing dimethoate, following directions on label. Repeat this drench after 7 days 

Preventative: Cleanliness in plant area. Drench plants each six months as above or spray once each month with insect spray such as Raid House and Garden Bug Killer.

BLACK FLIES: (FUNGUS GNATS) Black flies tend to swarm around plants. Insects are one-sixteenth inch long. These are nuisance insects and do little harm to African violets. When heavy infestations occur, root damage may result. This is caused by Black Fly larvae.

Treatment: Spray with an all-purpose house and garden spray or with Orthene. Should there be a heavy infestation, drench with dimethoate solution to kill larvae in the soil.

FOLIAR MEALY BUG: White cottony substance holds these bugs. This is found often in the leaf axils, on foliage or into the crowns of the plant.

Treatment: Cotton swabs with alcohol will eliminate most if the infestation is light. Wash treated leaves. Repeat several times when insects are seen. For heavier infestations, drench or spray plant with a solution of dimethoate. Malathion or Orthene may be used as a spray.

Prevention: Drench soil each month with a solution of Malathion or Orthene. An all-purpose house and garden spray may be used each month.

MITES: Members of the spider family, mites are very tiny and almost invisible to the naked eye. Three types of mites infest African violets: Cyclamen mite, broad mite or red spider mite. Treatment is the same for all three but symptoms are different.

CYCLAMEN MITE: Less than one-one hundredth (1/100) inch long. White, brown or amber in color. 
Center becomes yellowish, brittle and leaves twist and curl up. Leaves become excessively hairy. Flower buds are deformed and blotched. Plant growth is slowed and plants seem stunted. Centers become an ash-like color. Leaf cuttings will carry the insect.

BROAD MITE: One One-hundred-fiftieth (1/150) of an inch long. More active than Cyclamen mites. Similar symptoms of Cyclamen mite except that leaves turn down instead of up. Broad mites feed on lower area of leaves causing the leaves to turn down.

RED SPIDER MITE: Oval in shape, red spider mites may be green, yellow or red. They attack the undersides of leaves. Silvery or white webs may be seen. Yellow or brown specks may be noticed on the tops of the leaves. Plant may appear dull. 

Treatment for all mites: Spray with dicofol (Kelthane) each 5 to 7 days until plant recovers.

Prevention: Drench plants every six months or spray with dicofol. When infestation is severe, discard plants. 

ROOT NEMATODES: Microscopic worms. Suck juices from roots. May be noticed as knots or lumps in the roots. Plants wilt and turn an unhealthy yellow. Plants may be attacked by crown rot at this point. Nematodes can travel over wet surfaces and infect other plants. 

Treatment: Badly infected plants should be discarded. A drench may be applied using a solution of dimethoate. Repeat drench in 7 days. Then make another drench 7 days later. 

Leaf cuttings that have not touched the soil are safe to use.

SCALE: Scale insects are small, oval or round unusual shaped insects of one-sixteenth to three-eighth (1/16 to 3/8) inches in diameter. Scale has a hard covering which protects them from poisons. Insects may be white, black, brown, or grey. May be found in unsterilized soil or pots. They suck juices from plants. Scales secrete honeydew that is very sticky. The honeydew may serve as host to SOOTY MOLD. Plant becomes stunted and unhealthy. Plant will die unless treatment is taken.

Treatment: Malathion or Orthene solution used as spray or drench. Repeat every 5-7 days until insects are no longer seen. 

Prevention: Spray plants once a month with house and garden spray.

SOIL MEALY BUG: White insects one-sixteenth (1/16) inch long resembling grains of rice. Can go from plant to plant when watered in community trays. Unsterlized soil is a source of these insects. Plants become wilted and show unhealthy color. Crown rot may infect the plants. Leaf cuttings which have not touched the soil may be used. 

Treatment: Spray every ten days with Malathion or Orthene solution. Repeat every seven to ten days for two months

Preventative: Spray with malathion or orthene solution every six months.

SPRING TAILS: One-fifth (1/5 ) inch long thread-like insects. With a special appendage, these insects are able to jump quite high. They live on the surface of the soil or you may see them in the water given to your plant. Although they do not generally harm African violets, but a large infestation can harm the roots of the plant. 

Treatment: One cup of household bleach in a quart of hot soapy water used as a drench will kill these insects.

Prevention: Sterilize soil and pots.

THRIPS: Pale yellow to tan, they can jump or crawl when disturbed. These are sucking insects. Thrips pollinate flowers. Spilled pollen is often the first sign noticed of the presents of thrips.

Treatment: A cotton swab dipped in alcohol will kill the insects when they are touched. For heavy infestation, drench plant in solution of malathion or spray. Disbud plant, flowers and buds. Treat every five to seven days until thrips are no longer seen. Spray the surface of the soil with malathion or Orthene to kill nymphs. Remove all flowers and buds of the infested plant.

Prevention: Drench every six months with malathion or spray once a month with house and garden spray. Use No Pest strips.

WHITE FLIES: White, almost triangular or oval in shape may be seen on plants and under leaves. These are 1/16 inch long. They suck juices. Leaves may turn pale green, yellow then die. Honeydew is also secreted by these insects and this may serve as host for SOOTY MOLD, a black fungus. 

Prevention: spray once a month with house and garden insect spray. Treat the undersides of leaves.

DISEASES OF AFRICAN VIOLETS:

BOTRYTIS BLIGHT OR GRAY MOLD BLIGHT: High humidity and poor air circulation may cause the start of Botrytis Blight. The gray mold appears on buds and blooms causing them to turn brown and mushy. Leaves may turn brow and rot.

Treatment: Remove diseased or dead flowers and leaves. Give plants space and make sure leaves do not touch another plant’s leaves. Spray with Benomyl as directed on the manufacturer’s instructions. Botrytis blight is often carried by mites. Check plants for signs of mite and treat accordingly. Add fan to plant room.

CROWN ROT: Crown rot is caused by too frequent watering. Plants wilt, sometimes gradually, sometimes rapidly because roots are dying. Plant’s center turns brown. Plant’s leaves are covered with webbing; center leaves rot.

Treatment: Discard any plant that is severely infected. For other plants, repot using fresh soil. Add a fungicide such as benomyl to the new, fresh soil. Do not over water.

DAMPING OFF: This is a fungal disease. It appears on leaf cuttings and small plants often from seed rot. Plant will die. 

Treatment: Benlate drench one-to-one-and-one-half teaspoons to one gallon water.

GREEN SLIME: Caused by over watering and lack of air circulation

Treatment: Simply wipe pots clean when slime is evident. Be very careful with watering. Give plants sufficient space between each other for circulation. Use an electric fan for air movement but do not allow fan to face plants. 

PETIOLE ROT: (EFFLORESCENCE) Caused when leaf and leaf stalk come into contact with fertilizer salts. Orange or rust colored formations may be seen on the soil or the pot.

Treatment: Cut affected leaf. Flush water over the top of the root ball to rid it of accumulated fertilizer salts. 

POWDERY MILDEW: White powdery fungus that appears on leaves and stems. High humidity, poor air circulation and temperature changes promote powdery mildew which is airborne spores.

Treatment: Spray with benomyl. Lightly dust plants once a week with a product that contains folpet or provide good air circulation by allowing a fan to work 24 hours a day in plant area. Little saucers of sulfer may inhibit powdery mildew. A home-made recipe is to brush milk on the places affected. A home-made recipe of sprinkling cinnamon on the areas is effective but is not easy to clean off. 

RING SPOT: Yellow round spots caused by using cold water or when direct sunlight shines on wet leaves. These can not be removed. 

Treatment: Use room temperature water for watering and fertilizing.

STUNT DISEASE: Plant does not grow or bloom. If it blooms, blossoms are small, petioles short. Center leaves do not develop. 

Treatment: No known remedy. Symptoms could indicate root damage by symphylids (garden centipedes).


VIRUS DISEASES: It is difficult to accurately diagnosis virus disease since the symptoms resemble others when plants are infected with insects. 

PHYTOPTHORA: Nick-named “Sudden Black Death” because this strikes the center of the plant turning it black. It then spreads throughout the plant causing it to collapse. This can happen in 24 hours and is deadly. 

Treatment There is a treatment for phytopthora, ALIETTE, but this is available only to greenhouses. When you have a plant that you believe to have phytopthora, haste fully pitch the plant into the garbage before the disease has time to spread.

PYTHIUM: This is a soil-borne disease which attacks the crown then makes leaves whitish looking. Leaves and flower stalks become black although leaf stalk and blade remain green. The leaves then fall off the plant. 

Treatment: Plants affected have little chance of recovery. Sterilization of soil may prevent this.

VIRUS DISEASE: Leaves are mottled green and white and green and yellow. Some are spotted and show a mosaic pattern. Occasionally TOBACCO MOSIAC DISEASE is mentioned. I believe this is just being called “virus disease” now.

BLEACHED LEAVES: Too much light, too low fertility or lack of trace elements may be the cause. Chelated fertilizer may help.

BRITTLE LEAVES: It is possible that soil lacks magnesium or sulfer, possibly both.

BROWNED CENTERS: Over fertilizing, soil pH or water spilled in crown.

BROWN SPOTS ON LEAVES: Watering with cold water, chilling of the plants or water being trapped in the crown may cause this.

BUDS BUT NO BLOOM: Too low humidity or an infestation. Add dolomite limestone to soil to increase calcium.

BUDS DRY UP: Low humidity, poor air circulation, change of environment.

BUNCHED OR TIGHT CENTERS: Possibly due to sudden chilling or overexposed to lights.

DOUBLE TROUBLE: Double flowered varieties do not produce as well as singles. They may need better light, higher humidity and more plant food, perhaps more water when in bloom.

EARTHWORMS: Drench the soil with Nemagone 50 if available.