This investigation was carried out in a demonstrated field at Al-Ibrahimia district, El-Sharkia Governorate, Egypt, during 2019 season to study the effect of four postemergence herbicides namely, halosulfuron-methyl, fenoxaprop-p-ethyl, bispyribac-sodium and bensulfuron-methyl compared with control treatment under four rice cultivars (Egyptian hybrid rice 1" EHR1", Sakha 104, Giza 179 and Giza 178) on photosynthetic pigments and total carbohydrate, protein content, essential and non-essential amino acids.
The obtained results revealed that, no health problems were noticed for all rice varieties on the different experimental area. The lowest values of photosynthetic pigments and total carbohydrate were recorded for halosulfuron-methyl herbicide compared with other herbicides or control treatment. Addition of herbicides led to significant decrease in non-essential amino acids and protein content but, Aspartic amino acid was increased with application of bensulfuron-methyl herbicide. But, rice yield components were significantly incresaesed due to foliar application of herbicide.On other hand, EHR1 gave the highest values for physiological and biochemical parameters as compared with the other varieties. On other side, Sakha 104 cv. appeared to produce the highest number of panicle per m2, seed index and grain yield/fad. The interaction between factors under study had significant effects on physiological and biochemical parameters and yield components of rice were the results suggested that there a complementary effect between weed control treatments and rice cultivars by sowing Sakha 104 cv. and EHR1 with application of the tested herbicides.
The physiological and biochemical models of dual-herbicide-tolerant rice cultivars adds further informations to the knowledge of the crop herbicide tolerance degree for sustainable weed management in recent agricultural system.
Conclusively, The results of the study showed a decrease in the activity of physiological and biochemical content as response to the tested herbicide treatment at the recommended rates, and this was reflected in the values of essential and non-essential amino acids in the tested rice varieties. The rice crop components were also highly significant due to the application of herbicides.