A plant growth regulator for cotton harvest, which contains as an active
ingredient, a compound of formula (I): ##STR00001## wherein X is CH or
nitrogen; Z is halogen; A is oxygen, sulfur, or NH; R.sup.1 is hydroxyl,
C.sub.1 C.sub.7 alkoxy, C.sub.3 C.sub.7 alkenyloxy, C.sub.3 C.sub.7
alkynyloxy, C.sub.5 C.sub.7 cycloalkoxy, {(C.sub.1 C.sub.7
alkoxy)carbonyl}C.sub.1 C.sub.3 alkoxy, (C.sub.1 C.sub.7 alkylamino)oxy,
{di(C.sub.1 C.sub.7 alkyl)amino}oxy, (C.sub.3 C.sub.7
alkylideneamino)oxy, C.sub.1 C.sub.7 alkylamino, di(C.sub.1 C.sub.7
alkyl)amino, C.sub.3 C.sub.7 alkenylamino, C.sub.3 C.sub.7 alkynylamino,
C.sub.5 C.sub.7 cycloalkylamino, {(C.sub.1 C.sub.7
alkoxy)carbonyl}C.sub.1 C.sub.3 alkylamino, or (C.sub.1 C.sub.7
alkoxy)amino; R.sup.2 is hydrogen or methyl; and R.sup.3 is hydrogen,
halogen, C.sub.1 C.sub.3 alkyl, or C.sub.1 C.sub.3 alkoxy.
