THE IMPACT OF CLIMATE CHANGE AND GENETIC PROGRESS ON PERFORMANCE OF OLD AND RECENT RELEASED MAIZE HYBRIDS CREATED AT THE ARDS TURDA

Climate change effects on maize performance have been already detectable during the last twenty years in many parts of the world. This study aims to assess the relationship between climatic factors and maize yield, grain moisture at harvest and resistance of plants to broken and stalk lodging, with reference to maize hybrids created at the Agricultural Research and Development Station Turda (ARDS), in the centre area of Romania. The purpose of this study was to detect trends in the yield ability of 35 maize hybrids (18 historical and 17 recently released) and the possible association with weather trends. A significant increase in temperature both during vegetative growth and grain filling was observed, while rainfall presented a decrease in the critical period of flowering and grain-filling, during the last two decades (2000-2020), with large year to year variations. During the analyzed period, yields of the historical hybrids showed a reduction trend from -72 kg/ha/year for FAO groups 210-300, to -272 kg/ha/year for FAO groups over 300. The average yield of recently released hybrids showed an increasing trend from +91 kg/ha/year for FAO 300-hybrids, to +215 kg/ha/year for FAO groups 210-300. This suggests that genetic progress reflected in the release of new maize hybrids was able to counteract the negative effect of climate change seen on the yield of the historical hybrids. The yield difference between recently released hybrids and the historical ones showed the rate of genetic progress of +171 kg/ha/year for very early hybrids, +116 kg/ha/year for early hybrids, and +275 kg/ha/year for semi-early hybrids.