OWERVIEW ON THE MANAGEMENT OF POWDERY MILDEW IN WHEAT (BLUMERIA GRAMINIS F. SP. TRITICI D. C. SPEER) IN THE CONTEXT OF CLIMATE CHANGE

Powdery mildew (Blumeria graminis f.sp.tritici) is one of the most important wheat diseases that farmers claim first in cereals field in Romania. The incidence of powdery mildew in Romania varies from year to year depends on climatic conditions, cultivar susceptibility and inoculum amount. Most of winter wheat cultivars grown in Romania are moderate resistant and sensitive to powdery mildew therefore the risk of yield losses, especially during wet springs increases significantly without proper management strategies. The highest losses occur when the disease affects flag leaf, respectively 16% when the infection affects flag leaf after heading and 25% when the infection affects flag leaf before heading. In the context of climate change which impact host-pathogen relationship one of the best strategies to control powdery mildew in Romania is chemical control applied at stem elongation stage GS39 (flag leaf blade all visible) to booting stage GS43 (flag leaf sheath visibly swollen) and GS 59 (spike completely emerged above flag leaf ligule). However, changes in plant growth and physiology resulting from higher atmospheric CO2 concentration associated with changes in temperature and precipitation conditions can affect the efficacy of systemic fungicides altering their penetration, translocation and mode of action into the plants, which can determine a new fungicide application calendar.  Â