Background. Soybean is a thermophilic plant and is sensitive to unfavourable environmental factors. Therefore, the yield obtained varies depending on the growth location and study years. Habitat conditions in the south-eastern part of Poland are conducive to soybean cultivation, however, in other regions of the country satisfactory production can be limited by unfavourable weather conditions. The aim of the work was to evaluate the yield of soybean, cultivars Merlin and Lissabon, at three locations in the Podkarpackie Voivodeship. It was found that the number of pods per plant was the most flexible and the number of seeds per pod was inflexible. Both varieties reacted in the same way to the factors studied.  
Material and methods. Field experiments with the soybean cultivars Merlin and Lissabon were set up in the years 2016-2018. Experiments were carried out in three experimental stations in the Podkarpackie Voivodeship. Cultivars Merlin and Lissabon (Saatbau Poland Ltd.) give high and stable seed yield in the study region. Weather conditions are given according to the records of the Meteorological Station PAAC in Boguchwała (hot and dry) and the Meteorological Stations ESCA Przecław (warm and wet) and EDCA Nowy Lubliniec (warm and dry). Soil sample analysis was carried out at the laboratory of the District Chemical-Agricultural Station in Rzeszów.
Results. The cultivar Merlin, in comparison to the cultivar Lissabon, was characterized by a significantly higher plant density before harvest and crude fat content in the seeds, and by a significantly lower number of pods per plant and 1000 seed weight. The average soybean yield at ESCA Przecław, PAAC Boguchwała and EDCA Nowy Lubliniec was 4.18, 3.85 and 2.93 Mg·ha-1, respectively. In 2018, the highest protein content in grain and protein yield were obtained. In 2017, the highest amount of crude fat in seeds was found, but the fat yield was the lowest.
Conclusion. The quantity and quality of soybean seed yields were diversified according to the location of the experiment. Also, changing weather conditions in the study years had a significant effect on the studied characteristics and parameters. However, no significant differences were observed in seed yield between the cultivars (Merlin and Lissabon) depending on the study years. It is important to recommend varieties for a given region.

Jun 12, 2020
Original paper