Title: Inoculum Density Relationships for Infection of Some Eastern <scp>US</scp> Forest Species by <i><scp>P</scp>hytophthora ramorum</i>
Abstract: Abstract Our objectives were to establish inoculum density relationships between P. ramorum and selected hosts using detached leaf and whole‐plant inoculations. Young plants and detached leaves of Q uercus prinus ( C hestnut oak), Q. rubra ( N orthern red oak), A cer rubrum (red maple), K almia latifolia (mountain laurel) and R hododendron ‘ C unningham's W hite’ were dip‐inoculated with varying numbers of P. ramorum sporangia, and the total number of diseased and healthy leaves recorded following incubation at 20°C and 100% relative humidity. Calibration threshold estimates for obtaining 50% infected leaves based on linear analysis ranged from 36 to 750 sporangia/ml for the five hosts. Half‐life ( LD 50) estimates (the number of spores for which the per cent of diseased leaves reaches 50% of its total) from asymptotic regression analysis ranged from 94 to 319 sporangia/ml. Statistically significant differences (P = 0.0076) were observed among hosts in per cent infection in response to increased inoculum density. Inoculum threshold estimates based on studies with detached leaves were comparable to those obtained using whole plants. The results provide estimates of inoculum levels necessary to cause disease on these five P. ramorum hosts and will be useful in disease prediction and for development of pest risk assessments.
Publication Year: 2013
Publication Date: 2013-04-03
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 11
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot