Nitrogen fixation and protein content of five cultivated rare bush bean cultivars

The aim of this project was to examine and propagate bush bean seed material from the NGO “Arche Noah”. The human impact plays an important role in spreading plant material like seeds or roots from their areas of origin to other places. An example is the common bean Phaseolus vulgaris which originates from Mexico. During breeding the morphological and growth characteristics and yield parameters of five cultivars from the seed were monitored and analyzed. The commercial available and in organic horticulture still grown cultivar 'Saxa' served as a standard for comparison. A CNS (carbon, nitrogen, sulphur) analysis was carried out to calculate the contents of proteins in the seeds with values ranging from 25.5 to 29.9 wt %. To calculate the efficiency of nitrogen fixation an analysis of stable isotopes (¹⁵N, ¹³C) was carried out on bush beans and reference plants. The efficiency of nitrogen fixation was very low in all cultivars and ranged from 6.8 to 14.8%.The conclusion was that the investigated cultivars of bush beans could be a good choice for cultivation and can be considered for growing in horticultural production systems.