摘要:

AbstractWeights of rhizomorphs of undeterminedArmillariasp. obtained using ring‐trench and core soil sampling methods around aspen stumps in stands at different intervals after harvest were correlated. The core method was used to sample a second series of stands twice (at an interval of two growing seasons) at radial distances of 0.5, 1.0, and 1.5 meters from stump centers. Stands were uncut (at both samplings) or 3, 6, 9, 12, or 15 years after harvest (at the time of the initial sampling). Rhizomorphs were obtained from less than half the cores from the uncut stand, and the quantities (weights and lengths) were relatively small from both samplings. Mean numbers of soil cores yielding rhizomorphs and the mean quantities obtained generally increased as a function of the interval after harvest (and from the first to the second sampling), except for the oldest stan

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1991.tb00297.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA total of 22 fungicides were evaluatedin vitrofor their efficacy againstCylindrocladium quinqueseptatum(CQ),C. ilicicola(CI),C. floridanum(CF),C. parvum(CP), andC. camelliae(CC) causing various diseases ofEucalyptusin Kerala, India. Though there were a number of fungicides effective (ED100) in the comdial germination and poisoned food techniques, only carbendazim provided complete inhibition of CQ, CI and CC in the soil‐fungicide screening technique; carbendazim was also highly effective against CF and CP.C. ilicicolaappeared to be more tolerant than other species ofCylindrocladiumas only a few fungicides were found to be effective against it even in the conidial germination technique. On comparison of the three fungicidal evaluation techniques, it is concluded that, for a pathogen producing microsclerotia, likeCylindrocladium, the soil‐fungicide screening technique is the most appropriate one for obtaining reliable resu

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1991.tb00298.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractPhloem necrosis of rubber tree(hevea brasiliensis)is characterized by cel wall degradation, alteration of the middle lamella, the vesiculation of endomembranes, the formation of tylosoids and the internal coagulation of rubber.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1991.tb00299.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractSimulated acid rain (SAR) of pH 2.6, 3.6 and 5.6 (control) was applied toAbies balsamea(L.) Mill. saplings at 2‐week intervals for 3 years. Ambient precipitation was excluded from the trees during this period. Light to dark brown necrotic spots along the midribs of needles, 0.1 to 0.5mm in diameter and sometimes having a white center, were associated with the most acidic (pH 2.6) SAR treatment. These spots appeared over a significantly (p = 0.05) larger area of the foliage in the pH 2.6 treatment than in controls (pH 5.6). Needles that received SAR of pH 3.6 had intermediate numbers of spots. The spots persisted for at least 12/3years after cessation of SAR application. Needle retention, needle lengths, and the occurrence of epicormic shoots and the needle rust caused byUredinopsis longimucronataFaull were not significantly (p = 0.05) affected by the SAR treatments. Needle retention tended to be lessened by the most acidic (pH 2.6) SAR treatment. The occurrence ofLophodermium piceae(Fuckel) Höhnel needle cast was significantly lower in the middle tree sections of the pH 5.6 and 3.6 treatments than in the pH 2.6, drought and ambient treatments. Damage by naturally occurring insects was negligible, and was not related to the SAR treatmen

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1991.tb00300.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractIn foliage ofPinus sylvestris, Populus euramericana, andPicea abiesthe fatty acid composition was analyzed. Whereas clonal material of pine and poplar in controlled ozone fumigations did not show any significant differences as compared to controls, such differences were obtained in fieldgrown spruces showing needle loss.

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1991.tb00301.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryDamage symptoms, were expressed on detached shoots ofSalix repenswithin 24 hours of exposure to toxin preparations from culture filtrates ofRosellina desmazieresii. Many of these symptoms, which resembled those observed on diseased plants, could also be obtained in the test system by exposure to cytochalasin E solutions. This toxic compound is produced byR. desmazieresiiand may be important in symptom development, since culture filtrate preparations from isolates producing little cytochalasin E induced few symptoms.Toxin preparations fromR. desmazieresiiinduced damage on detached shoots of several woody species, including both hosts and non‐hosts of this fungu

ISSN:0300-1237    

DOI:10.1111/j.1439-0329.1991.tb00302.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY