Document Type : Original Article
                            
                        
                                                    Authors
                            
                                                            
                                                                            1
                                                                        Pesticide Dept. Fac. of Agric. Kafr EI-Sheikh Tanta Univ.                                
                                                            
                                                                            2
                                                                        Central Agric. Pesticides Lab. Agric. Res. Center, Dokki-Glza, Egypt                                
                            
                                                                            
                        
                        
                            Abstract
                            The effects of treatment with pesticides on some rice yield components were 
 studied. Results clearly indicated that carbofuran was the most effective on the 
 weight of grain yieldlhill, weight of 1000 grain, grain yield/fed. and straw yield/hill, 
 these values were 38.39 gm, 35.23 gm, 4.04 ton and 33.66 gm, respectively. 
 Diazinon came after carbofuran in their effect on the yield components of rice, the 
 weight of grain yieldlhill, weight of 1000 grain, grain yield/fed. and straw yieldlhill, 
 were 36.99 gm, 32.80 gm, 3.85 ton and 30.05 gm, respectively. The herbicide 
 thiobencarb was not effective on all components of rice yield except the effect on the 
 weight of grain yieldlhill. The persistence of pesticides in rice fields under flooded 
 conditions were studied. The residues of carbofuran in the water samples, were: 
 0.003, 0.034, 0.052, 0.028 and 0.020 ppm after zero time, one, two, three and four 
 weeks of treatment, whenever these values in soil samples were: 3.231, 2.511, 
 1.782, 1.352, 0.971 and 0.850 ppm after zero time, one, two, three, four weeks and 
 two months, respectively. Diazinon residues also detected in water and soil samples 
 during the period of experiment, these values ranged from 2.203 ppm at zero time in 
 the soil sample to 0.0004 ppm after four weeks in the water sample. The residues of 
 thiobencarb in the rice field water were decreased from zero time 0.8647 ppm to 
 0.0065 ppm after 4 weeks of treatment, while these residues in the soil samples were 
 increased from zero time to the second week and then decreased again. The 
 residues of the tested pesticides were not detected in all samples of rice grain.