PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Cereals are characterized by rapid seedling development and high stocking densities which generally result in good competition with weeds however intervention to eliminate undesirable flora is inevitable because the presence of weeds in a wheat field can cause yield losses of up to 70% depending on the region the nature of the weeds and the climatic conditions of the year. These losses are the result of competition for water mineral elements and light that directly affect the growth of the crop and subsequently on yield In addition massive infestations interfere with harvesting operations (cutting losses) and can even compromise them because of clogged grilles in crops that are overinfested with weeds and especially green (due to late rains) they can also cause storage problems if the product is not cleaned so the use of chemical weed control on fall cereals is a necessity to eradicate weeds and ensure good yields. In this study we tested the effect of eight herbicide treatments on the yield of durum wheat (​Triticum durum​) and its components in the Experimental Station INRA-Allal Tazi of the Gharb region (Morocco) during the agricultural season (2017-2018). The treatments used were in the form of single and combination of herbicides. The inventory carried out at the station revealed that the adventitious flora is represented by 24 species belonging to 13 botanical families. the majority of which are dicotyledons with 87.5% and therophytes with 87.5%. The results of our trial showed that all herbicide treatments significantly increased the grain yield compared to the non-weed control. Plots treated with Mesosulfuron-methyl + Iodosulfuron-methyl (Cossack) recorded the best yield (50. 7 q/ha) compared to simple treatments. The combination of Fenoxaprop-p-ethyl (Puma) + 2. 4-D + MCPA (Printazol) appears to be the most effective on weeds. This combination of herbicide achieved the best grain yield with 51. 3 q/ha.