Investigation of Cowpea (Vigna unguiculata (L.) Walp.)–Insect Pollinator Interactions Aiming to Increase Cowpea Yield and Define New Breeding Tools

Abstract

Impact of pollination on the agri-food sector is of paramount importance. Pollinators contribute to the maintenance of ecosystems, the reproduction and survival of many plants, and their presence usually leads to increased yield and quality of agricultural products. Breeding and selecting for plant traits for enhancing pollinator visits could therefore lead to more resilient farming systems. In stating the advantages of enhancing pollinators in agricultural systems, this study was designed aiming to assess six cowpea accessions for their flower traits and their effect on insect-pollinators. Pollinators species abundance and foraging activity was recorded and their impact on yield was investigated. Twenty-five of the twenty-seven flower traits studied differed statistically significantly among cowpea accessions. The main pollinators recorded belonged to the genus Xylocopa (Latreille, 1802). Seed and fresh pod yield was not affected by pollinators. The floral traits related to pollinators abundance and foraging activity were flower color, inflorescence position and the hours that the flowers per plant remained open during the day. However, they were not related linearly to pollinators abundance and foraging activity; therefore, they did not constitute safe traits for selection aiming to increase pollinators visitation. The findings suggested that other traits, such as pollen and nectar reward, probably perform a more important role in attracting pollinators compared to flower traits.