A master's thesis at the College of Agriculture at the University of Basrah discussed the response of the wheat crop to spraying ethephon at different growth stages The thesis of the researcher, Dua’a Nima Zuaibel, included a study of different concentrations of ethephon (0, 0.300, 0.600, and 0.900 kg of active substance H-1) in different growth stages {before the stage of ripple formation (ZGS18) and during the stage of rib formation (ZGS25) and the beginning of the stage of ripple formation (ZGS25) Elongation (ZGS30)} in growth characteristics, grain yield and its components in wheat. The results of the study showed that the concentration of ethephon 0.900 kg active substance H-1 was the highest in most of the characteristics of the study, as it recorded the highest average for the growth rate of the crop, the number of stalks, the grain yield, the vital yield and the harvest index, and the concentration of 0.900 kg of active substance H-1 recorded the lowest average for plant height and the coefficient of sluggishness sequentially. . The dates of spraying ethephon in different stages of wheat growth showed a significant difference in most of the characteristics of the study, as the treatment of ethephon spray at the stage of formation of ribs (ZGS25) gave the highest average of the area of the flag leaf, the efficiency of the spike, the number of spikes, the grain yield, the vital yield and the harvest index, with an increase in its amount sequentially compared with Spray treatment in the elongation stage (ZGS30). The thesis aims to know the study of the effect of spraying with different concentrations of ethephon in different stages of growth before the stage of ripple formation, during the stage of ripple formation and the beginning of the elongation stage on growth characteristics, grain yield and its components. The thesis recommended conducting other similar studies using different varieties of wheat and barley. Conducting similar studies using higher levels and on crops suffering from the phenomenon of sluggishness to understand the extent of plant response to ethephon and to determine the optimal level for it.
