The obtained results from evaluation the reaction of twenty-five sugar beet cultivars ( 100 day old) to the disease, explained that, the disease severity of the disease (powdery mildew) was high in the first tested season, while, it was low in the second season. The information of climatic conditions showed that, high differences in maximum and minimum temperature centigrade and relative humidity (RH) % between two tested seasons during the months which were the disease development within them (December, January, February and March),), therefore, the maximum and minimum temperature centigrade were high and the relative humidity % was low and suitable for disease distribution during first season comparing with the second season. Overall, the obtained results indicated that, FD17B4010, MK4199 and Alanya-KWS cultivars, were recorded the least disease severity % (high resistant) against infection with the fungus E. betae and could be recommended in future cultivation. In the contrast, Carma, Dipendra-KWS, Frappina-KWS, SV-2173 and Hammond cultivars, were the most susceptible cultivars(recorded the highest disease severity % ) which can be recommended eliminated and not be planted under Egyptian climatic condition. Moreover, efficacy of foliar spraying of treatments which tested included the essential oils Pelargonium graveolens at 10ml/L and Cymbopogon nardus at 10ml/L and natural substances of Frankincense at 2500 ppm and Chitosan nanoparticles at 500ppm, fungicide Topas 100, EC 1 mL \L , or sprayed with water (control) against powdery mildew disease was tested under field conditions.