摘要:

AbstractInvestigations into the dependence of beech bark necrosis on infection with Cryptococcus fagisuga in commercial beech‐(Fagus sylvatica)forests.Occurrence and sequence of attack ofFagus sylvaticabyCryptococcus fagisuga, slime flux, and necrosis were followed with four different methods of observation. Under average climatic conditions provocation and development of individual successive infection waves overlap to such a high degree that, because of the relatively short duration of the scale attack and because of the long duration and the great variation of the intensity of the necrotic reaction of the susceptible members of the beech population, individual waves of attack can hardly be discriminated in time and spac

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01275.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractIn tests under aseptic conditions, the herbicides hexazinone (PrononeTM5G® and Velpar L.R.®), glyphosate, and triclopyr reduced seedling growth and mycorrhizal development ofPinus contortavar.LitifoliaandPicea glanca.Triclopyr was most toxic of the tour herbicide formulations. Under greenhouse condition, only 2 formulations of hexazinone (PrononeTM5G® and Velpar L.®) were tested. At high concentrations (2 and 4 kg/ha) it reduced growth and mycorrhizal infections significantly but showed recovery with time. No adverse effects were observed at low concentration (1 kg/ha). In general, seedlings inoculated with mycorrhizal fungus (Suillus tomentosus), were more sensitive to herbicide than the ones without mycorrhizal inoculation. Under field conditions overall effects of herbicide application were less intense. Only 4 kg/ha rates of hexazinone resulted in reductions in seedling growth and mycorrhizal infections. The nonmycorrhizal seedings planted in the field developed mycorrhizae in over 40% of short roots within 2 months after planting in all herbicide treatme

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01276.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractComparison of basal area increments of paired healthy and declined oak trees shows a marked disjuncture beginning in the early 1950′ at 3 of 4 sample locations across the southeastern United States. An argument is presented that the change in growth was caused (or accelerated) by a series of severe regional droughts in the early 1950′s that impacted the trees which then responded by forming two distinct populations consisting of: 1. relatively healthy trees, and 2. declined trees. Both populations produced less annual basal area increment after several subsequent short‐term droughts, but marked crown deterioration and death appeared in the declined population after a moderately severe drought in the early 1

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01277.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractPinus resinosa, P. sylvestris, P nigra, Pseudotsuga menziesii, andPicea glaucaseedlings in three sites andPinus thunbergiiin two sites in New York State were inoculated with conidia ofGremmeniella abietinatwice in 1986. Percent infection therefrom was determined in spring of 1987, Some members of each species ofPinusbecame infected at one site within the current range of the disease and in other sites 84 and 300 km south of the current range.P. glaucaandP. menztesiiwere not infected. Results of experiments to test efficacy of postharvest treatments to eradicateG. abietinafrom infected seedlings suggested that immersion in hot (55°C) water and applications of dilute sodium hypochlorite would eradicate the pathogen with little or no effect on retention or color of foliage ofP. resinosaandP. sylvestris

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01278.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractDamages in Christmas tree‐plantations of Norway spruce by Rosellinia minor (Höhn.)Francis. In a plantation of Christmas trees of Norway spruce in the valley of Rhine (Vorarlberg, Austria) an epidemy ofRosellinia minor(Höhn.) Francis occurred in 1987 and 1988. 10 years old trees were totally affected by the fungus. Differences in fruiting‐structures betweenR. minor, R. herpotrichoides(Hept. and Davids.) andR. aquila(Fr.) de Not. are disc

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01279.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractInfection of plane tree by Ceratocystis fimbriata f. platani after contamination of water as growing substrate of wounded roots.Plane tree seedlings (Platanus acerifolia) were cultivated during 1. year so as some roots emerged from the culture pot And grow in the water of a container placed below. In April, these roots were wounded and nearby, conidia suspension of C.fimbriata†.platamwas injected into the water. 1 month later, foliage of some seedlings began to wilt and after 2 months, 7 out of 12 plane trees were drying. The pathogen was recovered from all parts of the roots above the water level inside the pots and as high as the collar for 4 plant

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01280.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractDry pollen ofPicea omorikawas fumigated with 820 μg/m3SO2for3,4, or 5 days. Few or no adverse effects occurred during subsequentin vitrogermination: germination percentage was not affected at all, and reduction of the pollen tube length was only 10% in pollen exposed for 5 days.Nevertheless pollination with fumigated pollen resulted in reduced seed production. 41% fewer seeds per cone were produced, and only 33% were filled seeds, compared to 70% filled seeds of the control. Seed‐weight was reduced from 3.6 g per thousand in the control to 3.0 g per thousand, when cones were pollinated with pollen fumigated for 5 days. Similar but less striking effects were found with pollen fumigated for 3 or 4 da

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01281.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY