Phenotypic stability and reonization maize hybrids

Statistical data and trial results have shown that maize grain yields in commercial production and trials alike vary according to both the year and the site. The hybrid is the single most important of the many factors affecting maize production and one whose effects, fortunately, can be controlled. Consequently, the best possible hybrid should be chosen for each agroecological region. With this goal in mind, large-plot trials with maize hybrids are established year after year in all major maize-growing regions in Yugoslavia. In the present study, we have calculated phenotypic plasticity, or adaptability, of maize hybrids in the agroecological conditions of the Vojvodina province. This was done based on the grain yields of 12 NS maize hybrids (NS300 (FAO 300), NS420, NS444 (FAO 400), NS501 (FAO 500), NS604, NS606, NS607, NS640, NS663, NS6666, Balkan, and NS645ulj (FAO 600)) obtained from nine sites during the 1999/2000 season. The highest average grain yield was produced by the hybrid Balkan and the lowest by the hybrid NS645ulj. The Vajska area was shown to be the most favorable part of Vojvodina for maize growing, while B. Topola proved to be the least favorable. Significant values (agreement) (W) of the hybrids ranked according to their grain yields were recorded at B. Topola - Erdevik - Ruma and Erdevik - Ruma - A. Šantić sites. In these areas, the same or similar hybrids are recommended for sowing in the upcoming period as well. A low correlative agreement, on the other hand, was observed at the following combinations of sites Kula - Sombor - Bečej and Subotica - Kula - Bečej. The low coefficient of correlation suggests that in these locations the right hybrids should be selected on a year-to-year basis.