EFFECT OF ADVANCED GENERATIONS ON THE YIELD OF DIFFERENT TYPES OF MAIZE HIBRIDS

Abstract

The increased cost of maize seed hybrid has caused again the commercial usage of advanced generations. The objetive of this research was to know the actual reduction in yield in different types of modern maize hybrids. F₂ and F₃ advanced generations were compared to F₁ single, three-way, double and intervarietal hybrids. The evaluation was conducted, during 1992, in three maize growing areas in the Nayarit State of México, 50 to 1000 meters above sea level, under good rainfall conditions. The decrease in yield for the F₂ and F₃ advanced generations was of 45.3% and 31.5%, respectively, with regard to the F₁ original hybrids. The negative effect on the yield was greater for the single hybrids with 50.5% and lesser for the intervarietal hybrids, 39.1%. The three- way and double F₂ hybrids yielded 47.3% and 43.7%, respectively, less than their F₁ hybrids. Negative effects also were observed in others agronomic traits, such as days to silking, lodged plants, ear rot and plant height. The advanced generations in maize hybrids are not suitable for commercial usage still in the actual modem maize hybrids.