Pyrethrin Spray

Discussion in 'Hydroponics' started by manels1111, May 27, 2008.

  1. manels1111

    manels1111 Registered+

    Man sorry guys for all the newbie threads. I realized yesterday I had a thrip problem. Brown spots on some of the older leaves with a shiny slail type trail on the leaves with very small black spots in the browning. I finally saw one of the larvae to clue me into a bug problem.

    Anyways I went right out bought some pyrethrin insect spray and followed the instruction spray throughly on the top and bottom sides of leaves. Anyhow a day later almost all my new growth has started to curl down with the older leaves appearing to be ok.

    Is there something I can do to help reduce the damage of the spray? Maybe water down the leaves or something or is the damage already done?
  2. the image reaper

    the image reaper Registered+

    Pyrethrins normally don't hurt the plant, and lose their toxicity after a short period of time ... pay close attention to the label directions ... pyrethrins are made from marigolds, and are a safe pesticide when used according to directions ... don't apply anything in the sun, as the sun's rays magnify in the droplets and burn the plant ... you can gently rinse off your plant with plain water, if you think it was over-applied, or just give it a day, and see if it recovers ... likely will snap right back, if the insects did no serious damage ... for the future: foliar-feeding should be done in the early daylight, when the under-leaves' pores are open, pesticides should be sprayed in the waning hours of daylight, when the pores are closed ... good luck :smokin:
  3. manels1111

    manels1111 Registered+

    Hmm I'm under a 600w hps and the plants are about 8inches tall. I sprayed them during the light cycle. Maybe it was another chemical in the spray. I used Garden Safe house plant insect killer. It listed what seemed like 100 vegetables and 20 house plants it was fine for including tomatoes.
  4. the image reaper

    the image reaper Registered+

    hopefully, your plants are 20-30 inches below your 600watt lamp ... if not, then thats probably why your plants suffered, after spraying ... :smokin:
  5. LOC NAR on probation

    LOC NAR on probation Registered+

    If your spray had any oils and I tried a few sprays with pyrethrins. All I could find had some kind if not neem oils. Good for spidermites but bad application. When you soak the plant with spray it will kill it . A light spray will get buy but only slow down the bugs. Get some foggers, like dr. doom. Just do a search they have small ones for small rooms. They did not seem to hurt the plants about 12 inches tall at all. I just went through this with a friend. The foggers need two hours of dark and please unplug all electric. I watch Mytthbusters. The light being on did not help.
    You need to break the life cycle of the thrip if that is your bug. I know with spidermites eggs hatch every 4 days. Adults have to be 14 days old to lay eggs. So 4 foggers at 4 days apart. All signs gone at my friends.
    Hope this helps.
    Last edited: May 28, 2008

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