Development of cv. BRS Novaera cowpea inoculated with rhizobium recommended for pigeonpea

Resumo

The cultivation of cowpea (Vigna unguiculata) has grown in Brazil, especially in the Cerrado of Mato Grosso, where it is produced in off-season. The association of cowpea plants with rhizobia has provided much of the nitrogen required by this culture. This study aimed at evaluating the development of cowpea inoculated with rhizobia recommended for pigeonpea (Cajanus cajan). The experiment was conducted at the Federal University of Mato Grosso, University Campus Rondonópolis-MT under greenhouse conditions. The experimental design was completely randomized with three treatments and four replications. The treatments were composed by commercial inoculant recommended for pigeonpea (composed by the combination of strains BR2003 and BR2801), nitrogen (without inoculation and application of 50 mg N dm^-3) and a control (without inoculation and nitrogen fertilization). Plants height, SPAD index, number of pods, number of grain, number of nodules, length of pods, dry weight of nodules, dry grain, dry weight of shoot and relative efficiency of the strains were analyzed. Cowpea show significant response for inoculation in all variables, with increase in production equal or superior to the treatment with nitrogen fertilizer. These results indicate the inoculant recommended for pigeonpea has potential use for cowpea under the tested conditions.