The economic viability of a fungicide application can vary greatly according to the price of corn and cost of the fungicide and application. Higher corn prices and lower treatment costs both reduce the break-even yield response; while lower corn prices and higher costs increase it (Table 2).
At a break-even yield response of 4 bu/acre, 65% of the Pioneer on-farm trials conducted over ten years would have seen an economic benefit from fungicide application (Figure 1.
However, at a break-even point of 8 bu/acre, the success rate drops to only 48%.
The 2009 Pioneer small plot trial also included different cropping sequences and tillage practices among locations (Table 1). Average yield response to fungicide application tended to be higher among locations planted to corn the previous year and locations using no-till or strip-till practices; however, high yield response at some locations was driven primarily by common rust pressure. Common rust does not overwinter in crop residue, so would not be affected by crop rotation or tillage practices.