Growth Stages of Field Peas Sensitive to Damage by the Pea Aphid, Acyrthosiphon pisum (Homoptera: Aphididae)

Publisher Website
Google Scholar
Abstract
Field experiments were conducted by caging groups of pea plants, Pisum sativum L., or pairs of flowers and pods and infesting them with various densities of pea aphid, Acyrthosiphon pisum (Harris). Plants infested up to time of flowering recovered from the damage and their yield was normal. Infestation of plants until flowers opened or longer reduced dry matter production, increased number of flowersand pods shed, reduced number of pods per plant and number of seeds per pod, increased percentage of empty pods, reduced weight of 1,000 seeds and yield of seeds, reduced weight of nitrogen-fixing root nodules, but did not affect protein content of seeds. All flower and pod stages were sensitive to direct feeding damage, but young pods were most susceptible. Feeding damage to flowers and pods was highly correlated with aphid density and young pods infested with four aphids for 4 days showed significant reductions in yield. We conclude that field peas must be protected from pea aphids for a 2- to 3-week period beginning when pods start to form.