摘要:

SUMMARY AND CONCLUSIONS1The temperatures of dormant and opening fruit buds of apple, black currant and raspberry have been investigated by thermoelectric methods.2Apple buds are warmer than the air by day, and usually cooler at night. Warming seems to be effected by radiation from the sun, since a screened bud was cooler than the air during the daytime as well as at night. Cooling would seem t o be a direct result of evaporation from the bud, with radiation as an important secondary factor on clear nights.3Black currant and raspberry buds are usually cooler than the air at all times. Buds of these plants were opening, whilst apple buds were dormant, and it would seem that loss of heat by evaporation dominates even the warming effect of the sun during the day.4Apple buds seem to have a mechanism of resistance against frost, whilst no evidence of such protection has been found in black currant buds.5Results are discussed further under the various headings of the text.In eonclusion, we desire to express our sincere thanks to Prof. J. H. Priestley for extensive help in the prosecution of the investigation here recorded, to Mr J. W. Eves of Leeds University, and to Mr A. Potts of the Fruit Station, Osgodby, for valuable assistance in obtaining the 1932 records.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05549.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SUMMARYExperiments are described which are concerned with the possibility of an increase or decrease in susceptibility to pathogenic fungi, induced or transmitted by grafting. Two diseases are investigated, namely, potato blight, caused byPhytophthora infestans(Mont.) dc By., and tomato leaf mould, caused byCladosporium fulvumCke.Preliminary inoculation experiments were carried out on eleven large‐fruited varieties of tomato, eight varieties of potato, various small‐fruited tomatoes, and other Solanaceous plants, with the following results:Phytophthora infestans.All the varieties of potato were equally susceptible, but certain varieties only of tomato, viz. Giant Red, Golden Queen. Detached leaves of the currant tomato were also infected.Cladosporium fulvum.Only tomato varieties and certain smail‐fruited tomatoes were susceptible. Giant Red and Golden Queen were particularly susceptible, Stirling Castle and Maincrop were relatively resistant. The currant tomato(Lycopersicum racemigerumLange orL. pimpinellifoliumDun.) was immune. No support can be given to Schmidt's suggestion that immunity depended on the presence of a substance termed “prohibitin”, capable of inhibiting spore germination. It is suggested that the identity of Schmidt's cultures was mistaken.About fifty grafts were made involving various combinations of resistant and susceptible plants. The grafts were inoculated, in most cases, after new growth had developed from stock and scion. Without exception, the results of these experiments were the same as on the ungrafted material, both stock and scion retaining their characteristic reaction to infection unaltered. Although negative results cannot be conclusive in themselves, they indicate that resistance and susceptibility are either genotypic properties of the protoplasm or else are due to some factor that is not, as such, transmissible from stock to scion orv

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05550.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SUMMARY1Glomerella phacidiomorpha(Ces.) Pet. has been found to be the cause of a disease ofPhormium tenaxin England. This is the first record of the fungus in Britain.2The fungus is only weakly parasitic, and is of danger only to plants of lowered vitality.3The imperfect fungusColletotrichum rhodocyclum(Mont.) Pet. is shown to be a conidial stage ofGlomerella phacidiomorpha.I wish to express my indebtedness to Mrs N. L. Alcock, Plant Pathologist to the Department of Agriculture for Scotland, who supplied the material ofPhormium tenax,and to Dr M. Wilson, Mycology Department, University of Edinburgh, who supervised the work.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05551.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SUMMARY1Isolates ofOphiobolus graminiscompared were obtained in England, Canada and Australia from the following hosts:Triticum vulgare, Agropyron tenerum, A. repensandHordeum murinum.2The optimum for growth of all isolates studied on carrot dextrose agar was in the neighbourhood of 25oC. They varied in their ability to grow at temperatures above and below the optimum.3Isolates vary in type of growth on carrot dextrose agar, the most noticeable difference being in the production of macrohyphae.4Saltation leading to the abundant production of black strands of macrohyphae by a culture producing very few was observed.5There are distinct differences in ability to survive desiccation over calcium chloride or 60 per cent, sulphuric acid. There seems to be some relation between the presence of macrohyphae and ability to withstand desiccation.6Isolates exhibit marked differences in general pathogenicity, but these differences are not specific towards certain hosts. Those causing greatest reduction in length of plants ofTriticum speltaalso caused greatest injury toT. dicoccum, T. monococcum, T. vulgarevarieties andHordeum vulgare.Conversely, hosts most resistant to one isolate were also those most resistant to the others.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05552.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SUMMARYThe salient points that deal with the disease of tulip fire are discussed, its names, the various forms of the disease such as fire, spot and a rot of the bulb, the symptoms of these, the distribution of tulip fire, its economic importance, its host specialisation and the relative susceptibility of varieties to it.The life history of the organism causing it,Botrytis Tulipae(Lib.) Lind is given, and the formation, germination, viability, and development of conidia and sclerotia in natural and artificial media are discussed. Infection studies in the laboratory and field with conidia and sclerotia are described, and the meteorological factors that favour artificial or natural epidemics.Observations and experiments dealing with control measures are given.Concluding this study the writers wish to acknowledge with sincere thanks the assistance given by growers and those otherwise interested in the cultivation of this crop, particularly to those that have given land, material, and the benefit of their experience.A. Beaumont thanks Messrs Tomlin Bros., Penzance, for supplying bulbs for experiments and much information on spraying and dusting.W. A. R. Dillon Weston thanks Mr H. Goude, the Horticultural Superintendent for Norfolk; Mr E. Cave, of Terrington St Clement,Norfolk, for land, material and his valuable observations and co‐operation; Mr W. Leake, of Messrs R. H. Bath, Ltd., Wisbech, for information on the susceptibility of varieties, and Mr J. R. Booer, of Messrs F. W. Berk and Co., Ltd., for the preparation of chemicals for work on bulb disinfection.E. R. Wallace thanks his colleagues at the Agricultural Institute, Kirton, and many growers in the Spalding distric

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05553.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SUMMARYA negative correlation has been shown to exist between the growth rate of seedling tomato plants and the length of the incubation period.Evidence has been presented, which suggests that the relative effects oftobacco virus1 on the growth rate of the plant subsequent to the appearance of symptoms is the same in both summer and winter.The percentage water content of all parts of infected plants was found to be lower than that of the controls, during the early stages of the disease. Later the water content tended to rise above that of healthy plants.In conclusion we wish to express our thanks to Mr B. D. Bolas for his interest and valuable advice.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05554.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SUMMARYCertain types ofActinomycesproduce a pungent odour which has frequently been described as “earthy”. This odour is caused by an organic compound which is slightly soluble in water, volatile in steam, soluble in ether, and partly soluble in alcohol. In concentrated form the substance forms a brown amorphous material with a penetrating manurial odour.When dissolved in water in concentrations as low as two parts in ten million it imparts to the water a pungentActinomycesor “earthy” taint which is particularly noticeable when the reaction of the water is maintained on the alkaline side of the neutral point.The existence of an excessive contamination of an important salmon river with odour‐producing actinomycetes was established. This contamination and the resultant pollution of the water with a pungent “earthy” taint was restricted to the tidal part of the river, where decaying organic matter was abundant.Acknowledgment is due to the Inspector of Salmon Fisheries for Scotland for his interest in the work. Thanks are also due to the Director of Chemical Research in the Department of Scientific and Industrial Research for facilities afforded in publication of the results of these experiments with which the Water Pollution Research Board of the Department has also b

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05555.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SUMMARY1A muddy or “earthy” taste can be imparted to the flesh of trout by material produced by an odoriferousActinomyces.2The taste resembles that imparted by a natural mud rich in actinomycetes.3The taint appears to be acquired through the gills and to be carried in the blood stream.4The taint can be slowly removed by clean flowing water.The authors wish to express their thanks to the Director of Fishery Investigations of the Ministry of Agriculture and Fisheries for permission to publish these results, and to the Inspector of Salmon Fisheries for Scotland for his interest in the work. Acknowledgment is also due to the Director of Chemical Research in the Department of Scientific and Industrial Research for facilities afforded in publication of the results of these experiments with which the Water Pollution Research Board of the Department has also been concer

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05556.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SUMMARYThe sorghum midge,Contarinia sorghicola(Coq.), is reported for the first time from the Anglo‐Egyptian Sudan.A short account is given of the distribution, life history, damage and control of this midge as it occurs in the Anglo‐Egyptian Su

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05557.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SUMMARYFrom the foregoing morphological descriptions of the main genera of the British Melolonthinae, it will be seen how much more closely alliedAmphimallusis toMelolonthathan isSerica.In nearly all details where the former species differs only slightly fromMelolontha, Sericais found to differ more widely. This therefore gives support to the practice of separating this subfamily into the two tribesof SericiniandMelolonthini.Since Scarabaeid larvae other than those of the Melolonthinae are also found damaging crops in the British Isles, a table for the rough identification of the most common genera is appended. All species of the Scarabaeoidea are not however included, and since genera such asGeotrupesandAphodiusmay be found at the roots of crops, confusion may occasionally arise in their identification, although they are not known to cause damage to plants. In such cases therefore reference should be made to the foregoing descriptions for exact identification.1(2) Body club‐shaped at caudal end, antennae long with joints of unequal length. 3.2(1) Body thickest at middle, antennae short with joints of equal length.Cetonia.3(4) Spines of radula arranged in two longitudinal rows 5.4(3) Spines of radula arranged in one transverse rowSerica.5(6) Longitudinal rows of spines on radula parallel or slightly converging at ends 76(5) Longitudinal rows of spines on radula diverging especially at caudal end.Amphimallus.7(8) Caudal aspect of mandibles with stridulating area made up of small pits.Melolontha.8(7) Caudal aspect of mandibles with stridulating area made up of transverse file‐like ridgesPhylloper

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1936.tb05558.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY