Formula (I): (In the formula, the variable portion is defined according to the specification) (for the control of harmful plants that is) a heterocyclic compound represented by the intermediates and methods, as herbicides and compositions containing them for the preparation of compounds suitable salts of Formula I, its agriculturally the A method for controlling use, the growth of undesirable plants also as well as include the plant a compound of formula I effective amount of at least one herbicidally manner, are allowed to act on the habitat and seeds thereof and / or it is in, the above method. None [Selection Figure]式(I):(式中、可変部は明細書に従って定義される)で表されるヘテロ環化合物、その農業上好適な塩、式Iの化合物を製造するための方法及び中間体、それらを含む組成物及び除草剤としての(すなわち有害植物を防除するための)その使用、並びにまた望ましくない植物の生長を防除する方法であって、除草剤的に有効な量の少なくとも1種の式Iの化合物を植物、その種子及び/又はその生息地に作用させることを含んでなる、上記方法。【選択図】 なし