The potential of tebuconazole for mitigating oxidative stress caused by limited irrigation and improving sugar yield and root quality traits in sugar beet.

Water deficit is the main reason for sugar yield losses in semi-arid areas. Triazole derivatives may mitigate the harmful impacts of water stress. Therefore, this study aimed to assess the effect of tebuconazole (TEB) application on antioxidants, root quality traits, and sugar yield under drought stress conditions. The treatments included three levels of irrigation set according to crop evapotranspiration (ETC): 100%, 75%, and 50% ETC, as well as three levels of TEB (0, 25, and 50 mg L-1). While significantly increasing antioxidant and alpha-amino-nitrogen (α-amino-N) contents, limited irrigation decreased total chlorophyll content, net photosynthesis rate, leaf relative water content, the weight of roots, and sugar yield. In contrast, TEB treatment resulted in a marked rise in all biological and physiological traits as well as enzymatic antioxidants. Our findings indicated that the decline in α-amino-N content might be linked to increased NR activity in response to the TEB application. Our results also showed that the stress-ameliorating role of TEB cannot be associated with the increase of flavonols (quercetin and rutin). Overall, the results demonstrated that TEB has a high potential for ameliorating the negative impacts of limited irrigation.