FPL 52 – Lophodermium Needle Cast The information accessed from this screen is based on the publication: Ziller, W.G. and R.S. Hunt. 1977. Lophodermium Needle Cast of in Nurseries and Plantations. Canada, Forest Insect and Disease Survey, Forest Pest Leaflet No. 52 4p. Introduction The name "needle cast" refers to a condition in coniferous trees where a sudden, severe loss of needles occurs. Although it can be caused by insects, climatic factors such as frost or drought, excessive shading, poor soil, or any combination thereof, needle loss is due mainly to the disease caused by fungi of the family Hypodermataceae (Phacidiales). Lophodermium pinastri (Schrad. ex Hook.) Chev. of the Hypodermataceae, is the commonest attacking the needles of ; it occurs throughout the world, but only on species of pine. It causes one of the most serious diseases of native pines in Europe, especially in nurseries and plantations (2), but in the forests of British Columbia, the damage is slight and economically insignificant. In response to recent enquiries about the increasingly severe defoliation noted in plantations of Scots pine ( L.) in the lower Fraser Valley, mainly attributed to Lophodermium pinastri, a short review on this needle parasite and its control has been prepared.

Hosts and Distribution Nearly all species of pine are affected to some degree, Scots pine, red pine ( Ait.) and Monterey pine (P. radiata D. Don) belonging to the commercially most important as well as most susceptible hosts. Degree of susceptibility varies greatly, depending not only on species and provenance of pine, but also on the strain of Lophodermium pinastri attacking it. There are numerous strains, races and varieties of L. pinastri, each differing in their capability to cause needle cast of each of the various pine hosts. Some of these types can be distinctly recognized and work on delineating them is currently underway (5, 11). Individual trees severely defoliated by L. pinastri often grow adjacent to healthy ones of the same species, age and provenance, indicating inherent resistance of certain trees to the same strain of L. pinastri. White (5-needle) pines are relatively resistant. Needle cast of white pines is generally attributed to another fungus, L. nitens Darker, but Lanier (3) found little difference between this fungus and L. pinastri and therefore considers L. nitens to be merely a race of L. pinastri. Pine needle cast caused by L. pinastri has been reported from North America, especially southern Canada and northern U.S.A., the West Indies, Europe, India, Japan, Siberia (9) and Australia (1O).

Life History and Recognition The first symptoms of Lophodermium needle cast usually appear in mid-summer. They are "small pale spots on the needles. These become yellow and then brown, spreading and merging, so that the needles take on a mottled appearance, gradually becoming completely brown" (4) (Fig). "However, these early symptoms are not unique to Lophodermium infection ....Moderate insect damage by sucking insects can also produce a similar appearance. These insects often escape detection by dropping to the ground when branches are touched" (10). Toward the end of the summer, characteristic narrow black bars may appear on dead parts of infected needles, together with minute brown to black spots (Fig), the asexual fruiting bodies (pycnidia). Shedding of the infected brown needles usually takes place during the winter or in the early spring. The sexual fruiting bodies (apothecia) are produced on the fallen needles in spring or summer (4). They are dull to shining black, elliptical, 0.30.7 mm in diameter and 0.9-1.5 mm in length, opening by a longitudinal slit when mature. After periods of rain, are released from the apothecia and become airborne, capable of causing infection on pine needles. These spores are enveloped by a gelatinous sheath and will therefore adhere to pine needles on contact. Under suitable conditions of temperature and high humidity, the spores will germinate on the pine needles by producing "germ tubes". The germ tubes will then penetrate the needles and cause new infections. The normal one-year life cycle of L. pinastri is thus completed. "In practice, however, the disease does not necessarily follow this straightforward course. It is certain that apothecia can ripen and infection take place throughout the summer (Rack 1955), and that they are occasionally produced at other times of the year. The fungus can remain alive in fallen needles under favourable conditions for considerable periods. Infection can take place on mature as well as on developing live needles, and it is clear from the universal infection of the needles on cut branches that it can invade dead or dying needles of any age. Thus while the worst cases of defoliation usually appear in the late winter or spring, as would be expected from the normal cycle, browning and needle-cast apparently associated with this fungus can often be found at other times of year. These variations in the time of infection and in the rate of development obviously make control by spraying a difficult problem" (4). Among the many causes that may contribute to pine needle cast, L. pinastri can be recognized easily by its conspicuous black apothecia on recently shed needles. With a microscope, identification may be confirmed by the presence of thread-like, gelatinous spores in the apothecia.

Damage In British Columbia, damage of economic importance is confined to nurseries and plantations of principally exotic species such as Scots, red and Monterey pine. Native pines such as lodgepole pine (Fig) generally are resistant to severe attacks by Lophodermium pinastri. In nurseries, the disease is serious if it affects seedlings intended for export, either to the forest for planting or for sale. Defoliated seedlings do not survive the rigors of planting and have little sale value. If they are carefully lined out or, better still, left in the nursery beds for another year, a high proportion, even of those worst affected, will recover (4). In Christmas tree plantations of Scots pine in the Fraser Valley, the lower crowns are most severely affected by needle cast, making many trees unsaleable. Frequently all but the current year's needles become brown, most of them being shed prematurely. Damage in the same plantation may fluctuate greatly from year to year, depending mainly on the amount of Lophodermium-infected needles in the litter, and on temperature, air humidity, and wind velocity and direction during the infection period.

Control Nursery Sanitation The fungus apparently travels only short distances and can be kept out of an area by using only clean stock (11). Nurseries should maintain an intensive spray program to keep the disease in check (6).

Silvicultural "W. Fischer (1957) considers pure plantations far more apt for the development of this disease than mixed ones. He particularly advocates an admixture of broadleaved trees, the leaves of which will cover the pine needles on the ground and prevent reinfection from them" (4). Spraying the litter with fungicides to destroy the spores before they leave the ground proved to be ineffective. "M. Leroy (1957) found that plants closely surrounded by vegetation were badly affected and therefore advocated clean weeding of young pine plantations" (4). Weeding probably reduces air humidity at ground level, thus inhibiting release from the dead pine needles. Spraying the ground with selective herbicides should accomplish the same purpose as weeding. "N P K trials in Korea's Knagwon Province showed applied potassium producing healthy pine seedlings tolerant to needle cast infection" (J. Korean Forest. Soc. Rep. 10. 1970). Potassium was found to build both plant health and disease resistance. Shearing trees and close planting restricts air movement causing a high incidence of the disease (11).

Selection of Resistant Pines "The possibility of increasing resistance to Lophodermium by selection of provenances or individual seed trees, and by breeding from resistant strains, has already been mentioned. This disease appears to offer one of the most promising fields for work of this kind" (4). In a recent experiment by Affeltranger (1), "four varieties (Bulgarian, Spanish, Turkish and French Auvergne) of untreated 1-0 Scotch pine were evaluated for susceptibility to Lophodermium needle cast. The Spanish variety was most severely damaged, with 80% infection. The remaining three varieties each displayed only 3 to 4% infection".

References 1. Affeltranger, C.E. 1972. Incidence and control of Lophodermium needle cast on Scotch pine nursery seedlings. Plant Dis. Rep. 56: 457-460. 2. Collis, D.G. 1972. Pine needle casts in British Columbia. Can. Dep. Environm., Pacific Forest Res. Centre, Victoria, B.C., Pest Leaflet No. 43 3. Lanier, L. 1967. Morphologie du Lophodermium pinastri (Schrad.) Chev. dans les conditions europeennes et americaines. Comparison avec le Lophodermium nitens Darker. Bull. Soc. Mycol. France 83: 959979. 4. Peace, T.R. 1962 Pathology of trees and shrubs with special reference to Britain. Clarendon Press, Oxford. 5. Millar, C.S. 1971. Two biotypes of Lophodermium pinastri in Scotland. Eur. J. For. Path. 1: 87-93. 6. Nicholls, T.H. and D.D. Skilling. 1974. Control of Lophodermium needlecast disease in nurseries and Christmas tree plantations. U.S. For. Serv. Res. Pap. NC-110. 7. Ormrod, D.J. 1974. Lophodermium control in Scots pine pays off. Brit. Col. Dep. Ag. Pl. Path. Notes 31: 8. Ormrod, D.J. 1974. Lophodermium progress report. Brit. Col. Christmas tree growers newsletter for March. 9. Spaulding, P. 1961. Foreign diseases of forest trees of the world. U.S. Dep. Agr., Handbook No. 197. 10. Stahl, W. 1966. Needle-cast fungi on conifers in the Australian Capital Territory. Australian Forest. 30: 20-32. 11. Staley, J.M. 1975. The of Lophodermia on pines, with special reference to problems in North American Christmas tree plantations. In: Lophodermium in pines. Proceedings of the 5th European Colloquium for Forest Pathologists, 15th to 17th April, 1975, Schmalenbeck. Compiled by B.R, Stephan and C.S. Millar, September, 1975.

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Figure 237-0035. Lophodermium needle cast on 1 year-old foliage of lodgepole pine.

Figure 237-0034. Discolored needles, and fruit bodies of Lophodermium needle cast on alpine .

Figure 237-0036. Lophodermium needle cast on older foliage of lodgepole pine.