Sources of inoculum of Lophodermium seditiosum on Pinus sylvestris¹

Abstract

Abs t metA survc)' oi the nicidenee oi PoplHidernunin sedilitisuni. /.. pinastri aiul /, co/iii^enuni m plantations c^i Pinus sylvestris in iuu"rh-cast Scvuland showed that /.. seditiosmn pretloinmateJ un lallen cones and on voung needles \\-liich lell prematurel\' in earh' summer. /,. piiidstri prcJominatcd (ui old senescent needles \\'hich fell m autiunn. The meulence ol /,. u>}ir.ienifin WAS low oii lallen cones and needles and it is not thought that this species could elfectix'ch lepLue L. seditiosmn.It !S concluded that the mam source ol L. ^ediiinsmn luoculuni ior inleciions m plantations ami ncarb\' nurseries is wnnig nifeeted tallen needles on whieh ascocarps iorm m Luc summer And autumn,

Fungicidal Control of Lophodermium seditiosum on Pinus sylvestris Seedlings in Swedish Forest Nurseries

“…Lophodermium seditiosum infects pine during late summer or autumn, the infection source being spores from ascocarps on fallen needles (Diwani & Millar 1990). After the snow melts in the spring of the year after infection, red -brown spots appear, and the whole needle eventually turns red.…”

“…Black, boat-shaped ascocarps are formed in summer or autumn. In humid conditions a shiny, greenish coloured longitudinal slit appears in the ascocarp and the threadlike ascospores are expelled; these can then infect new needles (Diwani & Millar 1990, Butin 1995.…”

“…These outbreaks could have an impact on reforestation since P. syl×estris is one of the main commercial tree species in Sweden. It has been suggested that the increased problems with L. seditiosum might be due in part to the occurrence of several consecutive mild winters, since climatic factors appear to play an important role in the appearance of disease symptoms (Diwani & Millar 1990, Butin 1995. Another probable reason for the increase in outbreaks is that the use of mancozeb: maneb compounds was prohibited in forest nurseries in Sweden in 1993 for toxicological and environmental reasons.…”

Occurrence of Lophodermium spp. in young scots pine stands in Latvia

“…Therefore, research has been done to develop effective fungicides to combat the disease (Millar, 1975;Ormrod, 1976). Weather conditions favorable for this disease are increasingly observed during recent decades -humid and warm autumns (as well as the end of summer) and mild winters (Martinsson, 1979;Diwani & Millar, 1990;Stenström & Arvidsson, 2001), making this period of time suitable for the studies of occurrence and impact of this disease. Hanso & Drenkhan (2007) indicate that Estonian climatic conditions (cold winters) are not an obstacle to the spread of the disease, which are favorable in late summer and autumn.…”

Identification ofLophodermium seditiosumandL. pinastriin Swedish forest nurseries using species‐specific PCR primers from the ribosomal ITS region

“…Lophodermium seditiosum infects pine needles during late summer or autumn (Diwani and Millar 1990). In spring of the following year, after snow melt, red to brown spots appear on infected needles.…”