VIEW ARTICLE

Effect of Low-Level Ozone Fumigation on Crown Rust of Oats. Allen S. Heagle, Plant Pathologist, National Air Pollution Control Administration, CPEHS, PHS, USDHEW, Crops Research Division, ARS, USDA, North Carolina State University, Raleigh 27607. Phytopathology 60:252-254. Accepted for publication 3 September 1969. DOI: 10.1094/Phyto-60-252.

Exposure of crown rust differential varieties of Avena spp. to 10 pphm ozone for 6 hr in the light for 10 days after infection with Puccinia coronata significantly reduced the growth of uredia. Urediospores produced on the plants exposed to ozone germinated as well, produced as many appressoria, and resulted in as much infection as spores produced on unexposed leaves. Exposure on dry leaves to 20 pphm ozone for 3 hr for 1-5 days did not affect urediospore germination, appressoria formation, or penetration.