Thidiazuron (in brief, TDZ: N-phenyl-Nl- (1, 2, 3 thiadiazol-yl)urea) was used previously as a cotton defoliant (ARNIJT et al., 1976). In some reports, this substance has been shown to have cytokinin-like activity (CAPELLE et al., 1983; MALIK and SAXENA, 1992 ) and also to be a main inducer for somatic embryo and/ or organogenesis in vitro in different plant species SAXENA, 1992, 1993; VISSER et al., 1992) .