The use of inoculants containing N-fixing bacteria for cowpea in the regions North, Northeast, and Central-West of Brazil is on the rise every year. However, in some cases, strains recommended for soybean have been used despite the existence of specific strains for cowpea. This study aimed to evaluate the performance of Bradyrhizobium strains recommended for soybean in cowpea nodulation and development. A greenhouse experiment was conducted with cultivar BRS Guariba, evaluating the soybean recommended strains: SEMIA 5079 (= CPAC15), SEMIA 5080 (= CPAC7), SEMIA 587 and SEMIA 5019 (= BR 29), two strains indicated for cowpea: SEMIA 6462 (= BR 3267) and SEMIA 6464 (= BR 3262), one mineral nitrogen treatment, and one control. The results showed that strain 587 presented similar biological nitrogen fixation efficiency in cowpea like the strains SEMIA BR 3262 and BR 3267. On the other hand, despite the high cowpea nodulations by the strains CPAC 15 and CPAC 7, the plant development, nodular efficiency and N accumulation was less efficient than of the strains BR 3262 and BR 3267, showing that cowpea inoculation with these strains is not advisable.
Vigna unguiculata; nitrogen; FBN
