At 30 days, the plants were thinned to a uniform population of 112 per plot, giving a population density of 72,500 plants/ha. Disease assessment was done at harvest using the methodology proposed by Perez and Bobadilla (2004). The total number of plants and the number of sick plants were quantified after examining the heads and ears for the presence of smut. The values ascertained were used to determine the Smut Incidence Percentage (SIP) and the Treatment Efficiency Percentage (TEP) using the following formulas: