Showing papers on "Bark published in 1970"

Canker of Eucalyptus grandis and E. saligna in Surinam caused by Endothia havanensis.

Abstract: Eu 19(>">. fue detectada en Surinam una seria enfermedad fungosa que causa chancTOs en el tronc o y la muette en ârboles de Eucalyptus grandis y E. saligna plantados en 19(>2. En /967, despuéi di un reconocimiento en las plantaciones establecidas it t ttas especit r, r< pudo déterminât qui la enfermedad se ptesentaba en todos las localidades en las cuales ban ùdo introducidas. El aislamiento, inoculation e identification probe que el agente causal tli la enfermedad es tl bongo Endothia havanensis.

Beech bark disease.

Abstract: The beech bark disease, caused by fungi (principally Nectria coccinea var. faginata) infecting minute feeding wounds made by scale insects (principally Cryptococcus fagl) in the bark of beech (Fagus grandifolia), is well established in the eastern United States and is spreading. Many beech trees are killed and weakened in infected stands, although some trees seem to have a natural resistance to the disease. There was little real concern about the disease in the U.S. until the last few years, when industries learned to use beech profitably. Now there is a need for better understanding of the disease. The beech bark disease presents an ironic paradox in the Northeast today. In the early 1930's, there was great concern over the beech bark disease, primarily because it was new. It was spectacular. No one could miss seeing the infested trees, the bright red perithecia and the decimated forests. Then the concern waned rapidly. Forest managers welcomed the disease because it was killing the big weed tree of the forest. Wood industries used very little beech, so there was no economic loss. In the last decade, however, the wood industries have learned to dry and use beech profitably. The supply was plentiful and the price low. Now that beech has gained acceptance, the beech bark disease is threatening the supply. For the first time real concern is developing over the disease. Questions are being asked: What can we do? Why don't we know more about this disease that has been here so long? The situation will get worse as the disease moves westward into areas where beech is dying because of a beech decline and injury caused by an oyster scale. In Europe, the disease has invaded all the beech forests. There are many healthy beech trees in Europe now, but where there are diseased trees only the aftermath stage is present. Mortality is not so common. In the United States, the disease has vast areas of beech forest yet to attack, and the disease is moving rapidly. This article is a summary of what we know about this disease now, with some pointers toward what we still need to know. Cause of Disease The beech bark disease, as it exists in the northeastern United States, is caused by fungi infecting minute feeding wounds made by scale insects in the bark of beech. The principal fungus is Nectria coccinea var. faginata Lohman, A.J. Wats., and Ayres (1). Nectria galligena Bres. and possibly other species of Nectria are also thought to be involved (70). The beech scale insect is Cryptococcus fagi Baer. A detailed account of the interaction of these organisms and others in the beech bark disease is given by Shigo (9). The hosts are the American beech (Fagus grandifolia Ehrh.) and all of its varieties. Trees of all sizes are attacked. History The beech bark was known in Europe before 1849 (4), and except for a few outbreaks, little little damage was caused by it. The beech scale was introduced into Halifax, Nova Scotia, about 1890. But the first recorded outbreak of the disease was not until 1920 (4). In the United States, Faull (5) first published information on the disease in 1930, and Ehrlich (3), reported a species of Nectria on dying beech trees. At the same time, Ehrlich (3) recognized 1 Presented at The International Shade Tree Conference in Detroit, Michigan in 1975. Previously printed in The Journal of Forestry, May 1972. 22 Shigo: The Beech Bark Disease the scale insect on ornamental beech trees in and about the Arnold Arboretum in Boston, Massachusetts. From 1929 to 1934, great concern developed over the disease and a study was made by Ehrlich (4). Very little research on the disease has been done in North America since that time.

Bark Beetle Pheromones

Abstract: KINZER et al.1 have recently reported the identification and synthesis of the bicyclic compound, frontalin. We wish to question the validity of some of their conclusions in the light of earlier work by this group at the Boyce Thompson Institute and Battelle Memorial Institute.

Elm bark derived feeding stimulants for the smaller European elm bark beetle.

Abstract: The principal feeding stimulants for the beetle Scolytus multistriatus Marsham from the twig bark of Ulmus americana L. have been identified as (+)-catechin-5-β-D-xylopyranoside and lupeyl cerotate.

Elements of bark structure and terminology.

Abstract: Bark structure varies considerably from that of wood, although analogies may be drawn between specific elements and overall structure and function. The terminology of bark structure is discussed and various cellular elements are described. Several bark structures are illustrated with light and electron micrographs pointing out differences between species and species groups.

Neutral terpenes from the bark of Sitka spruce [Piceasitchensis (Bong.) Carr.]

Abstract: Four of the minor components of the neutral triterpene fraction of Sitka spruce bark have been isolated and characterized as 3β,21α-dihydroxy-Δ14-serratene (1) (serratenediol), 3α,21 β-dimethoxy-Δ14-serratene (2), 3α-methoxy-21-keto-Δ14-serratene (3), and 3β-hydroxy-21-keto-Δ14-serratene (4). 13-Epimanool was characterized as its 3,5-dinitrobenzoate derivative.

Limonoid extractives from Khaya ivorensis.

Abstract: The timber of Khaya ivorensis contains khivorin, small amounts of swietenolide esters and other limonoids; the seed contains mainly methyl angolensate, and the root bark contains a complex mixture of limonoids. One of the new compounds from the timber, methyl ivorensate, has been found to contain a ring A lactone system, similar to that in nomilin, and is the first compound of this type found outside the family Rutaceae.