In realtà gli articoli dicono che il damping-off può essere generato dai 3 patogeni, non solo dal pythium, in quanto come dicevi tu il damping-off è una malattia dei semi o dei germinelli, non indica in sé quale patogeno l'abbia causata.
Turfgrasses are most susceptible to damping off during germination and seedling emergence. After emergence, the turf gradually becomes resistant to the disease as it matures. Damping off is most severe when temperatures or light levels are unfavorable for seedling growth. Pythium causes the majority of damping off problems during warm or hot weather, whereas Rhizoctonia is more prevalent during cool weather.
Fungicides are available for control of damping off, and may be applied as seed-treatments or directly to the seedbed. If damping off is observed, submit a sample to a diagnostic lab for accurate diagnosis because different fungicides are needed for control of Pythium and Rhizoctonia species.
Poi c'è una frase che mi fa pensare che, come dici tu, la maggior parte dei fenomeni di damping-off siano generati da pythium:
Note that fungicides labeled for damping off only have activity against Pythium species. The fungicides labeled for brown patch are needed to provide effective control of Rhizoctonia damping off. Please reference the disease profiles for Pythium blight and/or brown patch for fungicide recommendations if you know which pathogen is prevalent in your turf.
Quindi a livello commerciale, quanto etichettano un fungicida per damping-off danno per scontato che si stia parlando di damping-off da pythium (quindi propamocarb), però a livello scientifico la teoria prevede che tutti e 3 i funghi possano provocare il fenomeno e indicano come più probabile rhizoctonia in mezza stagione e pythium con il caldo. La questione sulla carta mi sembra quindi un po' incerta.
