摘要:

AbstractThis paper is a follow‐up of an earlier article on inland spruce cone rust published by the author in 1981. It discusses the impact of the disease on cone and seed production, and seed quality, including seed viability. The cone and seed production and seed viability were reduced to a lesser or greater degree depending on the severity of infection; in severely infected cones practically no seeds were produce

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01154.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractFollowing a hail storm in the southern Cape Province of South Africa, about 2000 ha of pine plantations were infected bySphaeropsis sapinea.The timber loss due toS. sapineainfection in compartments prematurely clearfelled was about 28% of volume and 55% of value of potential production. Total predicted volume of timber lost in compartments not felled prematurely was an average of 11.4%. Percentage volume lost increased with age, with the greatest losses being recorded on good quality sites.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01155.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractSap‐feeding nitidulid beetles were trapped for 15 months at four oak wilt centers in central Texas and assayed for the presence ofCeratocystis fagacearum.Levels of contamination with the pathogen ranged 0.3% (Kerrville) – 2.0% (Austin); also detected were C.piceaeat slightly higher levels and a low number of beetles carrying C.pluriannulata.The percentages of contaminated beetles were similar to those reported for other parts of the oak wilt range in the USA, but probable species differences in Texas were detec

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01156.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe needle‐infecting fungusPhaeocryptopus gaeumannii(Rohde) Petrak spread to stands of Douglas fir [Psendotsuga menziesii(Mirb.) Franco] in most parts of New Zealand following its first detection in the central North Island in 1959. At Hanmer Forest in the South Island, the percentage of infected needles rose more rapidly in a provenance from northern inland California than in one from Kaingaroa Forest in the North Island. Increase in infection was accompanied by a significant decrease in the proportion of needles retained on shoots of certain age classes, the reduction in the Californian seedlot being greater than in that from Kaingaroa. More older foliage was retained in the Kaingaroa provenance at Hanmer Forest, when infection averaged under 30 %, than at two other locations where mean infection exceeded 90 %. It is suggested that heavily infected production stands of Douglas fir suffer some premature casting of older needles, even when crowns appear health

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01157.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractSeeds of four species ofAlnuswere surface sterilized and placed on plates containing water agar. After seedlings had been produced, they were, without the seed coats attached, transferred onto malt agar plates. On such media, possible contaminants grew quickly and contaminated seedlings could be detected and discarded. With this method, numerous uncontaminated seedlings can be produced and used for synthesis experiments.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01158.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractIn a field experiment in southernmost Norway four young trees of each of eight coniferous species were subjected to artificial inoculation with the pathogenic blue‐stain fungusOphiostoma polonicum, associated with the spruce bark beetleIps typographicA dose previously known to Be lethal to most Norway spruce trees also killed individuals of Sitka, white, and black spruce, and Douglas fir. All Scots and lodgepole pines, and subalpine firs survived the given load of infection. Douglas fir did not exhibit the induced resinous defence reaction seen in spruce and pine. The fungus did not proliferate in the phloem of Douglas fir, but spread more easily in a tangential direction in the sapwood of this species than in spruc

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01159.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY