Cowpea (Vigna unguiculata (L.) Walp.) is an important food source. However, there is a lack of studies on this crop in Midwestern Brazil. Experiments were conducted in field conditions in Aquidauana, Mato Grosso do Sul, aiming to find genotypes less preferred by black aphid (Aphis craccivora (Koch.)). In April and October 2009, 20 prostrate genotypes were sown, and after germination the number of females and colonies were counted. At day 30, the percentage of infested plants was evaluated. In the experiment carried out in April and May, all genotypes were colonized by A. craccivora. However, the genotypes MNC99537F142 and BRS Paraguassu showed the smallest numbers of colonies. In May, the lowest percentages were found in the genotypes MNC99537F142, MNC01631F205 and BRS Paraguassu, with 6.3, 5.7 and 6.3 % of infested plants, respectively. Among the studied genotypes, MNC99537F142, MNC01631F205 and BRS Paraguassu should be further investigated for the selection of materials resistant to black aphids.
Antixenosis; cowpea; insecta; plant resistance; Vigna unguiculata
