The present invention relates to active compounds combinations which comprises (A) a lipo-chitooligosaccharide derivative and a further nematicide, insecticidal, acaricide or fungicidal compound (B). The present invention also relates to active compounds combinations which comprises further an additional nematicide, insecticidal, acaricide or fungicidal compound (C). Moreover, the invention relates to a method for curatively or preventively or eradicatively controlling harmful organisms, to a method for increasing yield or stimulating plant growth, to the use of a combination according to the invention for the treatment of seed or plant, to a method for protecting a seed and not at least to the treated seed.