Investigations of Ophiognomonia clavigignenti-juglandacearum: Inhibition by Butternut Bark Extracts and Viability of Conidia.

摘要

Inhibition of Oc-j by Juglans species bark extracts. A reliable disease screening technique is needed for detecting Juglans cinerea with resistance to butternut canker. Both naphthoquinones and bark extracts of Juglans species inhibited germination of Oc-j conidia, depending on the selections of butternut. Juglone and plumbagin were found. Juglone levels correlated with the bark extract bioassay in some months.;Influence of temperature and humidity on the viability of Oc-j conidia. Dispersal of Oc-j by vectors necessitates conidia to tolerate drying. Temperature and humidity influenced conidia germination and survival of air dried conidia. Conidia germinated on water agar over 4- 32°C and were viable after brief periods at 36°C when returned to lower temperatures. Viability of air dried conidia on nylon membranes varied from one day at 28°C, 90% RH to 16 days at 20°C, 80% RH. Conidia held at 100% RH remained viable for 168 days at all temperatures tested.