Open AccessGrowth, Sporulation, and Pathogenicity of the Raspberry Pathogen Phytophthora rubi Under Different Temperature and Moisture Regimes
Author(s) -
K. M. Graham,
Bryan R. Beck,
Inga A. Zasada,
Carolyn F. Scagel,
Jerry E. Weiland
Publication year - 2021
Publication title -
plant disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.663
H-Index - 108
eISSN - 1943-7692
pISSN - 0191-2917
DOI - 10.1094/pdis-09-20-1916-re
Subject(s) - blowing a raspberry , biology , phytophthora , root rot , mycelium , spore , horticulture , moisture , water content , pathogenicity , pathogen , botany , microbiology and biotechnology , chemistry , geotechnical engineering , organic chemistry , engineering
Phytophthora root rot of raspberry, which is mostly caused by Phytophthora rubi, is a significant issue for the Washington State red raspberry industry. Considered a cool weather pathogen, it is often assumed that it is most active and infective during the cool, wet winters of the region when soil temperatures range from 5 to 10°C; however, there are little data to support this view. More recent research has found that symptoms of root disease during late summer were strongly associated with P. rubi. Therefore, experiments were conducted at four temperatures from 5 to 20°C to evaluate the effects of temperature on P. rubi mycelial growth and sporulation and the effects of both temperature and soil moisture on the pathogenicity of P. rubi on red raspberry. At 20°C, P. rubi grew fastest and sporulated the most heavily. However, disease was most severe at both 15 and 20°C. The soil moisture parameters tested did not affect the pathogenicity results. These results show that P. rubi is more likely to infect during the spring and summer months (from May through September), when soil temperatures are consistently in the range of 15 to 20°C.