The effect of crop structure on the abundances and distributions of bruchids (Bruchus pisorum) in field peas (Pisum sativum)

Trabajo presentado en la International Conference Advances in grain legume breeding, cultivations and uses for a more competitive value-chain, celebrada en Novi Sad (Serbia) el 27 y 28 de septiembre de 2017.During 2014 –2017 distributions and abundances of B. pisorum eggs and infested seeds were analysed in field pea crops with different structure: pea monocrop (v. Protecta), pea monocrop founded as a combination of two varieties (Protecta with delayed start of flowering + Cisterski with early start of flowering –the second one sown in 6 m wide strips located along edges with Protecta), pea monocrop founded as a combination of the same two varieties –Cisterski sown in 3 m wide strips located along the plot edges and among the 16 m wide strips with Protecta and field pea/barley (Protecta/Sirael –60/40) intercrop. In general the levels of seed infestation were not significantly lower in pea/barley intercrops than in Protecta monocrops. In plots where the two field pea varieties were combined, strong tendency for aggregation of eggs into the zones with Cisterski was recorded. This tendency was more pronounced in the plots where Cisterski was sown in 6 m wide strips along the plot edges. The seeds of Protecta harvested from the plots containing strips of Cisterski were significantly less infested than the seeds from Protecta monoculture even the seeds harvested from pea/barley intercrop in 2014 –2016. When margins with the early variety show width of 6 m and the delay in the start of flowering of the main variety (the variety which occupies the inner part of field) is at least 10 days, the majority (90 % or more) of B. pisorum females lay their eggs on plants located at the margins.N