Vegetative cuttings can also carry inoculum or the live pathogen. This process requires immune mechanisms to kill or inactivate the inoculum of the pathogen. The period that overwintering spores require to cause infection depends on the inoculum source. These conidia are said to be the primary inoculum for "A. flavus". Fungicides are soil fumigants that are used to decrease amount of inoculum in the soil. Bacteria present in plant debris can serve as a source of secondary inoculum. The primary source of inoculum is Xcc infected seed. Pseudothecia that overwinter on infected barley stubble and act as the primary inoculum. Cankers were identified as one of inoculum sources for black pod disease. Infected plant debris is in most circumstances the primary source of inoculum. A primary inoculum of this disease is typically from cankers formed the season before. Crop rotation also helps minimize the amount of inoculum that results in infection. Wind is required for dispersal of the inoculum once it reaches the air. Blight can be controlled by limiting the source of inoculum. If inoculum is not added, fermentation could take up to 7 days.