ULTRASTRUCTURAL CHANGES IN ORIZA SATIVA, Echinochloa colonum AND Echinochloa crus-galli TREATED WITH FENOXAPROP-P-ETHYL AND PENOXSULAM HERBICIDES.

Cytological changes in rice oriza sativa (l.) cv. sakha 104, and two different rice weeds i.e. echinochloa colonum (l.) and echinochoa crus-galli (l.) after foliar application with fenoxaprop-p-ethyl at rate of 26.25 g a.i /fed. and penoxsulam at rate of 10 g a.i/fed. were investigated. mesophyll cell plasmolysis and unevenly thickened cell walls were showed in o. sativa after foliar application with fenoxaprop-p-ethyl. mitochondria multi- fission and increasing in mitochondria number per cell were found in rice and e. crus-galli mesophyll cells. thylakoid membrane reduction and plastoglubule were noticed in chloroplast of mesophyll cells in e. colonum were recorded. furthermore, re-growth of e. crus-galli and e. colonum occurred after foliar application with fenoxaprop-p-ethyl. these findings will improve our understanding for the tested herbicides mode of action in wanted and unwanted plants at ultrastructural levels.