Influence of Plant Densities on Some Yield Elements in Several Local and Foreign Soybean Cultivars in Transylvania Plain Conditions

Soybean can play an important role in securing the European protein resources. Transylvania Plain is a very favourable area for soybean crop. To optimise the crop management in these conditions, thirteen soybean cultivars (9 created at Agricultural Research and Development Station Turda and 4 of foreign origin) were studied with different plant densities and row spacing, in the specific environment of Transylvanian Plain. The yield increased by increasing the plant density up to 60 germinating seeds m-2, after which yield declined at the highest plant density. 60 g.s. m-2 plant population recorded the highest positive significant differences (approximately 10%), as compared to the average of all tested plant densities. The distance of 25 cm between rows produced a significantly higher yield as compared with the average of the trial. The climatic conditions influenced very significantly the yield variation (55.95%) while the genotypes, plant populations, and distances between rows had a statistically significantly lower influence (8.72%, 4.42% and 1.57%) compared to the effect of climatic conditions. The interaction between genotype and plant density contributed significantly (2.26%) to grain yield per unit area, while the interaction between plant density and row spacing had a statistically not significant effect of 1.09%).