ABSTRACT
P estic id es a re chem icals , m o stly sy n th e tic o rg an ic co m p o u n d s , u se d to con tro l w eed s a n d u n w a n te d o r h a rm fu l pests. Pestic ides can b e d iv id ed in to te n m ajo r ca teg o ries acco rd in g to th e ta rg e t o rg an ism s th ey a re d e s ig n e d to co n tro l (Table 11.1), a n d th ese ca teg o ries can b e fu rth e r su b d iv id e d in to a to ta l o f 22 g ro u p s acco rd ing to th e ir ab ility to kill, repel o r reg u la te g ro w th . The g ro u p s sp a n m an y chem ical c lasses, a n d the chem ical s tru c tu re s of th e v a rio u s p es tic id es d iffe r w ith in ca tego ries as w ell as b e tw e en ca tego ries. B ased o n th e ir chem ica l co m p o sitio n , o v er 1,400 co m p o u n d s a re in c lu d e d in th e classified lists o f p e stic id es o f the C o m p e n d iu m of P estic id e C o m m o n N am es, o f w h ic h so m e d isp la y ac tiv ity to w a rd s m o re th a n one ta rg e t o rg an ism (W ood, 2003). The five la rg es t g ro u p s of p e s tic id e s in c lu d e in sec tic id es (ta rg e tin g h a rm fu l o r d e s tru c tiv e insects), h erb ic id es , fu n g ic id es , ro d en tic id e s a n d acaric id es (R ittm ann a n d M e C arty , 2001).
