摘要:

AbstractExperiments on the behaviour under glasshouse conditions of schradan and demeton‐S applied to different species of plants are reviewed.Following application of schradan to leaves, some was absorbed and some evaporated. Absorption occurred both in light and darkness but higher temperatures accelerated initial absorption. Whilst the two surfaces of broad bean andColeusleaves were equally absorptive, the lower surface of apple and chrysanthemum leaves absorbed more than their upper surface. Application of demeton‐S to leaves was followed by three processes—evaporation, change into less volatile, toxic derivatives, and absorption, and the chemical was effectively removed from the leaf surface within a few hours. The products derived from demeton‐S were also absorbed but at a slower rate. The evaporation of demeton‐S gave rise to a fumigant effect.Translocation of schradan from treated leaves to other parts of the plant occurred, mainly in an upward direction and in amounts sufficient to kill aphids. Schradan was also found in the nectar of borage and mustard flowers following leaf application before the flowers had opened. The schradan appeared to be translocated in the phloem. Translocation from leaves treated with demeton‐S was never sufficient to kill aphids feeding elsewhere on the plant, and no unchanged demeton‐S and only small amounts of its toxic derivatives were found in untreated leaves or nectar.Species differences were found in the rate of breakdown of schradan after absorption from leaves and in the relative rate of breakdown of schradan in treated leaves and in those receiving schradan by translocation. The primary derivatives of demeton‐S were retained for several weeks, especially within treated leaves. The breakdown rates of both schradan and demeton‐S slowed down towards the end of the growing season.Following root application to broad beans in sand or soil, unchanged demeton‐S was absorbed and detected in the shoot tip where concentrations of demeton‐S and its primary derivatives were present in amounts sufficient to killAphis fabae.Movement in xylem following root application

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070901

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractKing Edward potatoes were treated with maleic hydrazide as a pre‐harvest foliar spray or with a preparation containing 3% of tetrachloronitrobenzene. In neither case was there any effect on the accumulation of reducing sugars when the potatoes were stored under cool conditions. A second experiment, in which two different maleic hydrazide treatments were given, also showed no effect on reducing sugar or sucrose behaviour during subsequent cool storage of the tuber

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070902

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractMethods are given for the determination of the four main classes of carbohydrate in wheat flour, viz., starch, pentosan, sugars and cellulosic material. The sum of the individual classes so found agrees closely with the figures obtained as ‘carbohydrate by difference

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070903

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe carbohydrate fractions of various types of flour available in the United Kingdom have been analysed into four main classes, viz., starch, pentosan, sugars and cellulosic material. The sum total of these classes has been found to correspond with the carbohydrate ‘by difference’. A correlation was observed between the amount of ‘available’ carbohydrate and the calculated digestibility of each type o

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070904

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe penetration of methyl bromide into packages during treatment by various methods of vacuum fumigation has been further studied using bagged whalemeat meal of high protein content. Results are compared with those obtained in similar tests on bagged wheatfeed previously described. The time during the fumigation at which restoration of the pressure to atmospheric secures the maximum effective penetration of fumigant is established. Whether or not such enhancement of the effectiveness of penetration is desirable in the case of a highly sorptive product such as whalemeat meal is discussed in the light of evidence that effective concentrations of methyl bromide remain at the centre of the bag for a considerable period after the usual airing procedures. Airing at reduced pressure is suggested as being likely to be more effective than the procedures at present followed.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070905

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

Abstract1. The mean proportion of nitrogen in 23 samples (representing 18 different composts) that nitrified in soil in 5 and 13 weeks was found to be 9.3 and 10.6% of the total nitrogen; this difference was not statistically significant.2. The amount of nitrogen in composts that nitrified in soil in 5 and 13 weeks correlated significantly with the amount of organic plus inorganic nitrogen in the composts that was soluble in cold O.IN‐hydrochloric acid.3. The percentage of the total nitrogen that nitrified in soil in 13 weeks was closely correlated with the nitrogen content of the organic matter in the compost for composts prepared from similar materials (sewage sludge and straw). There was no similar correlation, however, for composts from different materials (sewage sludge and town's refuse, coir fibre, cotton‐waste, et

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070906

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractCephalocroton cordofanusseed oil has been examined and found to consist chiefly ofcis‐12:13‐epoxyoleic acid (62%) along with linoleic (17%), oleic (10%),threo‐12:13‐dihydroxyoleic acid (4%) and saturated acids (7%). The structure of the epoxy acid follows from its identity with the acid fromVernonia anthelminticas

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070907

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe problems involved in the infra‐red study of dairy products are considered and a special type of liquid absorption cell for such samples is described. Spectra of various dried products are presented and the effects of protein‐carbohydrate interactions upon infra‐red spectra are disc

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070908

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractImmobilization of nitrogen in the presence of sucrose has been compared in 24 soils differing widely in origin and composition. Marked differences were found in the amounts of nitrogen immobilized in the various soils, these being correlated with the pH, phosphate content and carbon/nitrogen ratios of the soils.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070909

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractProduction of carbon dioxide and accumulation of inorganic nitrogen have been studied in a group of 27 soils differing widely in origin. Samples of each soil were incubated for 28 days at 23.5° and 30°. Further batches of soil were incubated at 23.5° after partial sterilization by steaming, and others after air‐drying and re‐moistening.Significant relationships were found between the carbon and nitrogen mineralized under each of the experimental conditions tested. Steaming and air‐drying the soils generally increased the mineralization of both carbon and nitrogen, as compared with untreated soils incubated at the same temperature, and resulted in a lower ratio of carbon to nitrogen mineralized.The amounts of nitrogen and carbon mineralized were significantly correlated with the total nitrogen and organic carbon contents of the soils. Evidence was obtained that the organic matter of intensively cultivated soils is more resistant than that of maiden soils to further microbiological decom

ISSN:0022-5142    

DOI:10.1002/jsfa.2740070910

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY