摘要:

AbstractMeasurement of the CIELAB colour variations of the Norway spruce needles [Picea abies (L.) Karst.] to detect the action of the air pollutants, in the experimental open‐top chambers of monitored pollution. Evaluation of the spruce needles yellowishness by the mean of the colours parameters (L*, a*, b*, C*, h*), and the Fourier transformation of the reflectance curves.The colour parameters of the yellowishness of spruce needles observed during the experiments in open‐top chambers with the controlled pollution can be measured quantitatively by mean of the CIELAB system L*, a*, b*, C*, h, parameters. The study of the reflectance curves in the fourier transformation provides also significant coefficients of the colour differences. Three different provenances of the spruce, 5‐year‐old, shows great differences in saturation (C*), and hue an

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01123.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractA test involving field‐inoculation of three year‐old cypress seedlings was evaluated to find clones resistant toSeriatim cardinale.A satisfactory proportion of resistant trees was found, but it was significant different among three provenances and also among families. Best results were obtained from the provenance of Sames, followed in decreasing order by the provenances of Rhodes and Kr

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01124.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractA stem‐girdling basal canker of autumn olive,Elaeagnus umbellata, was found in Illinois and Indiana.Tubercularia vulgariswas determined to be the causal organism by using field pathogenicity tests. The perithecial state of the fungus was not found. Symptoms of the disease are describe

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01125.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractLaboratory studies investigating the influence of environmental, host and cultural factors on conidium morphology of isolates ofMarssonina brunnea, M. castagneiandM. populiestablished that conidial features (length and breadth dimensions, shape, conidium ratios, L:B, LS:B and septum location) were remarkably stable. Significant differences in length and breadth dimensions and ratios were induced by culture media and host but not by media pH, incubation temperature, photoperiod, leaf age, leaf surface and infection severity. Significant differences in conidial dimensions and ratios ofM. brunneawere observed following examination of monthly collections from a single field‐grown tree. The variation in conidial features induced by environmental, host and cultural factors in no instance obscured taxonomic differences between specie

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01126.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,Sphaeropsis sapineainfected about 2000 ha of pine plantations. A series of sample plots yielded information on symptom development in relation to site factors and stand characteristics. Aerial photography and ground inspection of the area showed that, although the intensity of disease was not affected by site quality or age, it was inversely proportional to altitude.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01127.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractTests were carried out in controlled environments to ascertain the effects of some physical, chemical and biological characteristics of soil on the spread ofRosellinia necatrixand on the development of its infection in poplars. Following the results obtained, cultivation techniques have been suggested which could prevent the diffusion of the fungus or reduce the damage it causes.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01128.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThree scolytid species consistently associated with Dutch elm disease were assessed and compared for their effectiveness as vectors ofOphiostoma ulmi.Assessments were based on the number of beetles within a sample carrying any detectable O.ulmi, the number of O.ulmispores carried by individual beetles and the number of discrete gallery systems colonised by O.ulmi.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1990.tb01129.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY