Abstract

"The experiment was conducted at the research station farm of the faculty of Agriculture university of Omar AL-mukhtar , ELBaida - Libya , during (2021-2022) growing season The main objective of this experiment was to study the effect of the flag leaf to the formation of grain yield and its components for five varieties of wheat crop through a split plot experiment by in randomized block design three Replications, the results of the study were as follows. The results of the statistical analysis showed that the difference between the genotypes is significant with the superiority of the cultivars Marjawi, Ain Al-Faras, Humeyra in both the number of spikelets/ spike, grains / spike , biological, grain and straw yield ton/e and the 1000 kernels weight. While Sargula cultivar gave the lowest averages for most of the studied traits. The differences reached a high level of significance between the studied genotypes by removing the flag leaf, where the removal of the flag leaf caused a significant decline in each of the plant height, spike length (cm). Number of spikelets , grains / spike. Biological, grain and straw, yield ton/ha, 1000 kernels weight. (g), and harvest index. There is a positive significant correlation between the flag leaf area and the grain yield in the durum wheat crop, as it was shown through this study that the varieties that have a flat flag leaf give a better grain yield resulting from an increase in the weight of one 1000 kernels weight., which indicates the importance of the presence of the flag leaf in determining the degree of grain fullness During the fullness period and then in the 1000 kernels weight as one of the most important components of the crop in grain crops. It can be conclude the importance and significant of vital role of flag leaf to contribution of grain yield about by 12%, number of grains / spike by 8% and 1000 kernels weightcontributed by 10% "