Nodule formation ability of common bean (Phaseolus vulgaris L.) cultivars

In the course of 1994 - 1995, a field experiment with 26 local and introduced common bean cultivars (Phaseolus vulgaris L.) was carried out at "Dobroudja" IWS, Bulgaria. The aim of the study was to evaluate their nodule formation ability. The genotypes were tested on the background of 3 agronomic treatments: 1. Without treatment (control); 2. Nitrogen (N) - 90 kg/ha and 3. Rhizobium inoculation (RI). It was established that the local cultivars had a very good nodule formation ability and had no positive response to RI with selected rhizobium strains. On the contrary, the introduced cultivars had bad nodule formation ability with native rhizobium strains but they showed a very good response to inoculation with selected rhizobium strains. Positive correlation was found between the size of seeds, growth habits, shoot dry matter, the seed color and the nodule formation ability.