The bulb onion (Allium cepa L.) is an important product in the Boyacá economy, for which it is necessary to preserve the quality and productivity of its cultivation. Within the department, the highest production rate is found in the Alto Chicamocha Irrigation District (DRAC), since it offers appropriate environmental conditions for crop development. Physicochemical and biochemical parameters are considered important to determine soil quality. Biochemicals, due to their high sensitivity, allow us to quickly know the changes that occur in the soil, in this case, the one cultivated with bulb onions. Likewise, the bulb onion is the target of pests that cause detriment to its quality and production, one of these is the fungus Sclerotium Cepivorum, which causes white rot, a limiting disease of the crop due to its difficult control due to its propagation and dissemination characteristics. The use of plant extracts is proposed as an alternative to control these pests. This book addresses three important fronts in the phytosanitary and physiological study of bulb onion cultivation: the assessment of the phytosanitary conditions of the crop and the identification of the specific agronomic characteristics of the región, the evaluation of the isolates of native microorganisms as possible biocontrollers in the Sclerotium Cepivorum – Allium cepa L. model at the field level, and the establishment of the effect of some plant extracts on the fungus Sclerotium Cepivorum at in vitro and in situ levels. With the above, it is proposed to establish an integrated management system for sustainable production and the reduction of phytosanitary problems in the cultivation of bulb onions.