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FORBID 4F to use or not to use?

Discussion in 'Marijuana Plant Problems' started by cruzer101, Nov 20, 2008.

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    cruzer101 Well-Known Member

    Hey everyone,

    I had spidermites show up 3/4 of the way through my last grow. I thought I controlled them with safers soap and no pest strip. I used home made tobacco tea also.

    Well they are back. I am 4 weeks into flower and after trying the same thing they are still sucking the life out of my plants.
    No webs yet but I see a few of them under the leaves and there egg sacks. The buds on that plant are suffering.
    I think the no pest strip is helping but not taking them out.

    I grow in a scrog do I dont have much access to them.

    OK, I found a new product called Forbid 4f that works through the leafs and got some. Now I am not sure if I should use it.

    Has anyone used this stuff and lived to tell about it?

    cruzer101 Well-Known Member

    by Roger Bryan
    All rosarians know that the two-spotted spider mite (tetranychus urticae) is a serious rose garden pest. This nearly invisible insect works on the bottoms of leaves sucking the chlorophyll out of them. Spider mites can take a healthy bush to a leafless stick in a matter of days unless thwarted by constant vigilance of plant health and condition, and by an intensive spray program using Avid to kill the adult mites and Hexygon to kill the eggs and larva, or Floramite to kill all life stages. The aforementioned chemicals all work as contact or, at best, translaminar (i.e., Avid) sprays so special care must be taken to spray the undersides of the leaves – Avid, being translaminar, does penetrate the leaf structure and will move from the top surface to the bottom, but it only kills the adults. The life cycle of the spider mite – from egg to adult – is five to 20 days depending on factors such as temperature and humidity. If you don’t get all life stages when you spray, the mites will probably return, and they may have become resistant to the spray(s). But help is on the way!

    Bayer Environmental Science has just announced the registration of a new miticide, based on a proprietary new chemistry with a unique mode of activity. The name of this new miticide is Forbid 4F, and its active ingredient is spiromesifin, a tetronic acid, which blocks fat synthesis so the mites dry out and die. This mode of activity, inhibiting lipid biosynthesis thus causing dessication (i.e., drying-out), is virtually the same as that of soaps and oils. That is, the MOA for Forbid 4F can be considered, for the sake of simplicity, to be MOA 6 as defined in papers elsewhere on this website, and in articles appearing in the Rose Society’s newsletter, Basal Breaks. This is great because MOA 6 has little or no potential for the development of resistance – an analogy [1] would be a flamethrower: you may miss some of your targets, but when they return they’ll be no less vulnerable to the flame.
    Another feature of Forbid 4F is that, like Avid, it is translaminar. The active ingredient, spiromesifin, while not systemic (i.e., it does not move through the plant’s vascular system like, for example, Merit does), is absorbed by the plant’s leaves and will move from the tops of the leaves to the bottoms where the mites feed. This ability to move from the tops to bottoms of leaves significantly reduces the tedium of the spray process – while care should still be taken to cover the entire bush, rigorous spraying of the undersides of leaves should not be required. Moreover, according to Bayer, Forbid 4F controls mites at all life stages and offers an excellent residual of four to eight weeks for mites.

    The label for Forbid 4F indicates its toxicity rating is CAUTION (be aware that the Avid label carries a WARNING designation). The label further specifies a usage rate of 2 to 4 fluid ounces per 100 gallons of spray. This equates to 1/8 to 1/4 teaspoon per gallon of spray – Bayer recommends, however, using the lower rate. Also, Forbid 4F may be tank mixed with sprayable fertilizers, insecticides and fungicides, although Bayer recommends a jar compatibility test. This product is available through Bayer distributors, such as Southern Ag ( Southern Ag ) in Boone , NC . A very knowledgeable contact at Southern Ag is Mike Presnell (e-mail: [email protected] ). It will also be marketed by OHP (Olympic Horticulture Products) under the name Judo. Lastly, it’s available in 8 oz. bottles which cost $224.20 from Southern Ag. The cost per gallon of spray is about the same as Floramite, but remember this product is translaminar – Floramite is not. And, this product has a longer residual effect.

    REMEMBER: Read the Label!

    I got mine on ebay. Very small sample like 1/8 of an oz in a vial with a dropper for $25 plus shipping of $5 but its so concentrated thats all I will need for a couple years.

    So, anyone used the yet?


    cruzer101 Well-Known Member

    Well, what I got out of that is that it is not systemic.
    "(i.e., it does not move through the plant’s vascular system like, for example, Merit does)"

    But it is not good to smoke at all so I guess if I can just hit the lower leafs and than throw them out it may work...


    mika181980 Member

    We had a horrid infestation that involved 3 species (yes 3). We had mites with green spots, mites with brown spots, and mites with bright red spots.

    After hundreds of dollars in foliars and additives and a professional spray done we researched this pest inside-out I have forgotten the name of the man who was suggesting the cold. He was an Entomologist so assume he knew his bugs.

    We scrapped what we could not save and removed all veg life from the entire home. Then our grow room A/C waas set as low as it would go which we did for 30 days.

    Since that time we have had numerous successful grows, keep our grow room sealed and well-ventilated, and grow only from our own seeds and clones.

    It is sometimes tempting when we read of this or that clone we could pick up for a few dollars but the mite-mare we created doing just that caused us keeps us to our own grow.

    I hope these words will help someone.

    pointswest Active Member


    This states on the label it is restricted for greenhouse use, feed and forage crops, fruit trees and vegetable gardens. I don't think I would use any flowers grown on this plant if sprayed with this.

    LionsRoor Well-Known Member

    I've used it - more than once and lived to tell... just barely!

    This stuff is last resort. Gnarly shit. You aren't doing anybody any favors using this shit. Only go here if all else fails. I'm assuming Azatrol (or some form of it) as a foliar did not work?

    Forbid will save your grow, though you need to understand this will NOT be medical grade cannabis. On the other hand, if you have things 'on the line', and need to make a grow work at all costs - then go there. It will work and get you through - just please let end users know the risk when they choose to use these tainted flowers!

    Wetdog Well-Known Member

    It is indeed 'gnarly shit' and so far, it's the most effective miticide I've ever used. In another life, I was a licensed applicator.

    You also picked about the worst time for a mite infestation. Forbid has a 30 day residual effect and you're 4 weeks into flowering. If there is ANYTHING else you can use (besides Floramite), to get you through to harvest, use that. "I" wouldn't use Forbid in flower.

    What I do, is spray my clones a day or 2 before flipping to 12/12 and have stayed mite free through flower (so far, knocks on wood). This is what I suggest you do for the next go round.

    Two things though with this stuff. Don't over apply, except as per directions where you go overstrength for the initial application and don't apply anything else for the 30 days after an application.

    Goggles are a great idea, respirator is also, but it's really nasty on the eyes.

    Good luck.


    j420man Member

    i am a medical grower in co. and i use anything possible to treat mites i dont agree with the statement that its not medicle grade if you use forbid or avid or floramite but i will stress that these are for veg only you should never spray flowers with anything i wouldnt even spray mine with neem oil youre going to smoke it and sick poeple cant smoke that anymore than chemicals or dead mites i spray all plants going into bloom with forbid it lasts 40 days if you have a 55 day strain this only gives the mites 2 weeks so they cannot gain any ground in youre bloom room however one thing i dont here poeple say is after sprayed youre plant will grow new leaves and those new leaves can be infected so i spray with forbid then put them into 12/12 always wear clean clothes when entering youre grow room basically act like you have mites when you dont treat youre plants anyway thats what i do and it works for me try to get them all though cause if you use organic or chemical they will build a resistance to it so use three different treatments i'll mix it up between organic and chemical keep grow room clean if you had an infestation remember spray the plants but treat the room ass well with bleach water i myself just use a fogger hope that helps but remember always avoid spraying flowers with anything i dont care what labels say it all leaves residue and you will smoke it but i do prefer forbid for pre bloom spray cause of the 40 life on it and it does work well and i couldnt imagine what you would do to get a full on infestation before you chop hope this helps
    j420man :idea:

    cruzer101 Well-Known Member

    Will do, Thanks for the info.
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