Avaliação de híbridos de milho quanto ao complexo de enfezamento

Abstract

In the last crop, it was possible to observe, specifically in the southern region of Brazil, an increase in the incidence of the so-called stunting complex, transmitted by the leafhopper Dalbulus maidis, directly compromising the production of this cereal. Knowing that the use of genetic resistance of hybrids to this disease is characterized as one of the best control alternatives, since there is no way to control the disease after mollicutes infection and understanding that obtaining new hybrids takes time, materials used have been analyzed because they often do not present information about their tolerance. From this, the objective of this work was to analyze the tolerance of corn hybrids regarding the corn stunting complex. The experiments were carried out in the experimental area of the Universidade Federal da Fronteira Sul Campus Cerro Largo, under a completely randomized design, with 5 treatments consisting of different corn hybrids sown on two different dates, with 4 replications, totaling 20 experimental units each experiment. The hybrids used were: AG 9025 (T1), AS 1666 (T2), 10A40 (T3), DKB 235 (T4) and NK 467 (T5). Each experimental unit consisted of a plot measuring 3 m wide by 4 m long with a spacing of 0.5 m between rows and 0.25 m between plants, for a population of 80,000 plants per hectare. It was considered as the first date, the sowing that occurred on August 29, 2021 and the second date, the one that occurred on October 18, 2021. The evaluations of plant height, incidence, severity, disease index were carried out at the phenological stage grain filling and productivity when the plants were maturing for harvest. It was possible to observe the greater tolerance of the 10A40 hybrid to the stunting complex in relation to the other hybrids evaluated, where it presented lower rates of incidence and severity in the conditions in which the experiment was carried out.