Optimara Growing Tips
Start to Finish
8
PLANT PROTECTION - PEST AND DISEASE CONTROL
• In General
--
For a complete list of chemicals used in the violet production, concentrations
per application, and active substances, see tables at the end of this section or call the office at 1-
800-443-2290 if you have specific questions.
Plant protection procedures for African Violets should "only" be performed in the late afternoon
and under moderate greenhouse temperatures. If used at temperatures of above 80°F, some
chemical have a devastating effect on your crop. The water temperature of the spraying solution
should not be below 70 to 75°F, depending on the leaf temperature of the plants. Be careful with
plants in bloom! Spray-mist plants only very lightly, because otherwise damage to the blooms
could occur. The ideal spraying method for violets is Colfogging at about 2000 lbs. This method
leaves little or no residue on the plants.
• Watch Out! --
Some spray chemicals can cause severe damage on the blooms. Always
make sure that when using unfamiliar spray or drench chemicals you test them on a small test
group (i.e. one table). Do not apply a new method to your whole crop all at once - You may loose
your crop!
Pests
These are preventive measures to fight pests: Approximately 10 days after potting, you should
spray African Violets with Vydate to control nematodes. This spraying sequence is a good
preventive measure for fighting the most common pests.
• Mites --
One can recognize mite infestation by the very hairy, deformed, and yellowish
looking leaves in the center. The growth is disturbed. If the plants have not been treated on time,
the damage occurs also on the blooms. The first flowers are often very small and crippled;
sometimes they do not appear at all.
If you notice that the plants are infested by mites, spray the entire African Violet crop with either
Avid, Thiodan 35 or Kelthane MF three times over the following 10 days. Kelthane is our
preferred choice, however, it leaves a light residue on the plants.
• Leaf Nematodes --
Leaf nematodes appear on the underside of the leaves. You will see
a glassy, shiny tissue on the underside of the plants between the main veins. The leaves will look
wilted and show brown spots. Heavily infested plants will be stunted in growth, and individual
leaves will die off.
If you detect any signs of leaf nematode infestation, spray Vydate or Metasystox. For maximal
control, apply 30 gallons of spray to 10,000 sq.ft. until the surfaces of the plants are wet. Repeat
the spraying 2-3 times within 10-12 days to get rid of all nematodes.
