ABSTRACT A field experiment designed in a randomized complete block design was conducted at Itay El-Baroud Agriculture Research Station, El-Behiragovernorate, Egypt during two growing seasons of 2017-2018 and 2018-2019 to study the effect of chemical, organic and bio-fertilizers on the growth, seed yield and powdery mildew disease incidence and severity of canola plants ( Brassica napusL.) c.v. Serw 4. Results indicated that, 50% NPK fertilizers + Humic soil application (SA)+ Humic foliar spray (FS) significant increases seed yield/fed and oil yield/fed in both seasons. In the same way, 50% NPK +Humic (FS) significant exceeded all treatments in increasing branches number/plant, plant height, plant dry weight, leaf area/plant, number of seed per pod, number of pod per plant , 1000-seeds weight, seed yield/plant and reducing powdery mildew disease incidence and severity in both two seasons. Finally, the highest oil percentages were obtained from canola plants that treated with H (FS) + H (SA) in both seasons.