Response of different cultivars of wheat Triticum aestivum L. to spraying by growth regulator (Ethephon)

A field experiment was carried out at Al-Hartha Research Station, which is one of the agricultural fields of the College of Agriculture, University of Basra (30 km north of the center of Basra Governorate), during the winter season 2021-2022. In order to study the effect of spraying by growth regulator (ethephon) at a concentration of 2.25 ml l-1 at tillering and elongation stages on growth, yield and quality of ten cultivars of bread wheat (Triticum aestivum L.): Al-Baraka, Al-Rasheed, Ibaa-99, Babil, Mawaddah, Bohouth-22, Bengal, Jad, Wafeya and Jihan), a factorial experiment was applied according to a randomized complete block design (RCBD) with three replications. The results showed that wheat cultivars differed significantly in most of the character of the study. The cultivar Bohuth-22 recorded the highest grain yield and harvest index of 5.652 t ha-1 and 35.21%, respectively, due to its superiority in spikes number of 395.00 spikes m, but did not differ significantly from the two cultivars Mawaddah and Al Baraka in grain yield, as they recorded 5.323 and 5.085 t ha -1 respectively as a result of their superiority in one or more of the yield components. The results also showed the superiority of the Babil cultivar in the qualitative character, as it recorded the highest percentage of wet protein and gluten, with an average of 13.43 and 32.78% for the traits, respectively. The results showed that spraying wheat plants by ethephon increased spikes number per m², grains number per spike, and 1000 grains weight. This was reflected in an increase in the grain yield, with an average of 5.043 t ha-1, the highest protein content in an average of (13.63%). The spraying of ethephon positively increased the proportion of wet gluten in wheat grains. The effect of the interaction between the cultivars and spraying with ethephon on spikes number and percentage of wet gluten. The combination between cultivar Bohuth-22 and the plants sprayed by ethephon was superior in spikes number per m, with an average of 452 spikes m-1, and the combination between cultivar Babel and plants sprayed with ethephon excelled in the percentage of wet gluten in the grains 37.34 %.