Prevalence of Ascochyta pinodes on Field Pea Seed Produced in Central Ethiopia and its Relation to Seedling Infection

Abstract

Ninety-four seed samples o f field pea (Pisam sativum) from major production areas of central Ethiopia were assessed for prevalence of Ascochyta pinodes using blotter method in the laboratory and seedling symptom test in the greenhouse. Consequently, percentage seed infection with A. pinodes varied from location to location and from sample to sample. Out of tested samples, 57.4% were infected with A. pinodes where some were severely infected as high as 23%. Highest mean prevalence of 8.6% was recorded from Ziquala followed by Minjar with 6.7%. Low seed infection was recorded from Ambo (0.7%), Chelia (1.1%) and Guha Tsiyon (1.0%). All heavily infected seed lots (>15%) were from Ada, Ziquala, Minjar and Kulumsa comprising 7.4 % of the total seed lots while all seed lots from Ambo, Chelia and Goha Tsiyon had infection <5%. No production area was found free of this pathogen. Though blotter method yielded slightly higher incidence, strong and positive linear relationship was obtained between seedling symptom test (dependent) and blotter method (independent variable) explained by equation Y = 0.8429X - 0.2611 (df = 92; R2 = 0.9408**). A. pinodes was found to be transmitted from seed to seedling at the rate of about 84% being highly seed transmissible pathogen. Hence, either method could be used for assessing this pathogen. Most seed lots had germination percentage over 96%, though seeds
from Sendafa had lower germination percentage (92.2%). There was no correlation between seed infection by A. pinodes and germination percentage of the seeds.