Seed-borne Phoma betae as influenced by area of sugarbeet production, seed processing and fungicidal seed Treatments

Factors influencing the prevalence of Pleospora bjoerlingii on sugar‐beet seed

“…According to Leach & MacDonald (1976) this should also affect seed infection with P. betae. In 1974 most sugar-beet seed crops grown in England were raised under cereal cover crops and grown on in situ, but a few were transplanted.…”

“…The time elapsing between cutting and threshing, the moisture content of the threshed seed and therefore the amount of post-harvest drying are mainly determined by rainfall. According to Leach & MacDonald (1976) this should also affect seed infection with P. betae.…”

“…Byford (1972) reported that in seed samples tested between 1958 and 1970 the mean percent infected by P. betae in any year was not less than 20%. Rubbing seed before sowing removes some of the superficial infection (Gambogi & Byford, 1976;Leach & MacDonald, 1976;Weisner, 1967). Weisner (1967) reported that large polygerm seed clusters gave seedlings more severely attacked by P. betae than small monogerm seed clusters, but this is the only report of factors other than weather affecting the initial incidence of seed-borne P. betae.…”

Identifying and Distinguishing Seedling and Root Rot Diseases of Sugar Beets

“…Sugar beets are susceptible to a number of seedling and root rot diseases that are primary constraints to profitable sugar beet production (5,11,14,15,33,43). The majority of the seedling diseases are caused by soilborne pathogens, but Phoma betae is a seedborne fungal pathogen that can cause both seedling and mature root problems during the season (19,20). Since numerous other environmental and cultural factors may also cause symptoms that could be easily confused with symptoms caused by these pathogens, it is important to be able to correctly identify and differentiate between the various diseases and problems in order to most effectively manage them.…”

“…Seedling disease has most often been attributed to AG4, but isolates belonging to AG2-2 have also been isolated from affected seedlings (35). Aphanomyces cochlioides and Phoma betae are primarily limited to infecting plants in the Chenopodiaceae, and the closely related Amaranthaceae (19,29).…”