SEVERITY OF HELMINTHOSPORIUM LEAF BLIGHT IN POPCORN HYBRIDS AT DIFFERENT SOWING DATES

Abstract

The culture of popcorn (Zea mays L. var, everta) is more susceptible to leaf diseases when compared to common corn. In addition, there is a huge shortage of hybrids with tolerance in particular to helminthosporiosis (Exserohilum turcicum). Within integrated disease management, the combination of different practices is critical to successful disease control. In this sense, the positioning of the sowing season, the preventive use of chemicals, and the use of genotypes that have a greater tolerance to helminthosporosis, are some of the strategies. Thus, the objective of the study was to evaluate the severity of helminthosporosis in different hybrids and sowing times of popcorn. The experimental design was a randomized block experiment in a bifactorial scheme (4 x 6), with four sowing dates (08/21, 09/11, 09/30 and 10/19/2019), six popcorn hybrids imported from the United States (H1, H2, H3, H4, H5 and H6) and four repetitions. For sowing up to 9/11, all hybrids had low severity of helminthosporiosis, which allows us to conclude that the sowing of popcorn in this region should be carried out between August 20 and September 10. For all sowing seasons, hybrids H3 and H1 showed superiority in tolerance to helminthosporiosis.