Epidemiological insights into the management of Septoria leaf blotch and leaf rust in durum and bread wheat in the semi-arid regions of Morocco

This study was conducted over two cropping seasons in arid (Jemaat Shaim) and semi-arid regions (Sidi El Aidi) of Morocco. It identified key factors driving the development of Septoria leaf blotch (SLB) and leaf rust (LR) on 14 wheat varieties with three fungicide regimes (none, one, or two applications of propiconazole). Results showed that disease control depended on the site and crop season climatic conditions, varietal resistance, and fungicide strategy. In less humid conditions of Jemaat Shaim, a single fungicide treatment at the heading-anthesis stage reduced SLB AUDPC by 18% and disease progression by 25%. Two applications at stem elongation and heading reduced these variables by 72% and 44%, respectively. At Sidi El Aidi, with more humid conditions, a single fungicide application reduced SLB and LR AUDPC by 12% and 17%, and disease progression by 36% and 25%. Two fungicide applications of what? further reduced SLB and LR AUDPC by 45% and 43%, respectively, and disease progression by 54% and 30%.