ISSN:0022-5142    

DOI:10.1002/jsfa.2740020502

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractAn examination of the Morgan ‘quick’ test showed that the amount of phosphate extracted from soils increased with the widening of the ratio, soil/extractant, and with the period of extraction; the maximum extraction was obtained in most soils by shaking the soil with the extractant for I hr. Of the likely phosphorus‐bearing constituents of soil Morgan's reagent dissolves mainly calcium (and probably magnesium) phosphates; organic forms of phosphorus dissolve only to a small extent. In the soil examined, Morgan's test failed to distinguish the effect of 17 successive annual applications of superphosphate at the rate of 100 lb. per acre. However, it did detect, decisively, corresponding applications at the rates of 200 and 400 lb. per acre.The Morgan test further demonstrated the depression of phosphate availability by repeated application of ammonium sulphate, the opposite effect of liming, the very substantial increase in availability after the application of dung, the absence of any effect of treatments with potassium sulphate and an apparent seasonal variation in phosphate status in the soil exa

ISSN:0022-5142    

DOI:10.1002/jsfa.2740020503

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractAlthough numerous investigations have been directed towards relating chemical structure to insecticidal activity, little work of this type has been carried out with ovicides. This paper describes the results of ovicide tests using some phenyltrichloromethylcarbinols and their esters against eggs of Tetranychus telarius L.The laboratory method employed for assaying ovicidal activity, which was developed at the Cheshunt Research Station, is described.4‐Chlorophenyltrichloromethylcarbinol and its acetate were the only compounds showing appreciable ovicidal action, but the following relations between ovicidal activity and chemical constitution were indicated by the results: (a) toxicities of phenyltrichloro‐methylcarbinol and its esters are increased by the introduction of C1— and, to a lesser degree, of CH3— into the para‐position of the ring; (b) the ovicidal activity of the carbinols is reduced by esterification; (c) the 4‐chlorobenzoates appear to be more toxic than the corresponding 4‐nitrobenzoates, but less toxic than

ISSN:0022-5142    

DOI:10.1002/jsfa.2740020504

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractThe serviceability of lined kraft‐paper bags for packaging cornflour has been assessed in statistically‐designed transport trials. Closely similar results were obtained by laboratory drop‐tests. Conventional strength‐tests on the kraft paper showed no correlation with the behaviour of the bags in

ISSN:0022-5142    

DOI:10.1002/jsfa.2740020505

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractComparison is made of the Dyer, Truog and Morgan tests for available phosphate in soils using long‐term fertilizer trial plots. All three tests recorded the cumulative effects of annual applications of superphosphate and the more marked effects of dung; however, the actual values indicated by the tests differed. The Truog and Morgan methods, but not the Dyer test, reflected the depressive effect of ammonium sulphate and the beneficial effect of lime on phosphate availability. Test data are compared with the recovery of phosphate by a flax crop. A seasonal variation in the available phosphate in soil was indicated, notably by the Morgan and Truog tests: it was more marked in plots receiving annual dressings of superphosphate than in those receiving dung, untreated controls occupying an intermediate position in this respec

ISSN:0022-5142    

DOI:10.1002/jsfa.2740020506

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractGlucose is slowly destroyed when heated in neutral solution and the rate of destruction is accelerated by sulphuric acid, but to a much greater extent by hydrochloric acid. Sulphuric acid has therefore been chosen as a suitable starch‐hydrolysing agent and conditions of hydrolysis have been developed whereby starches may be estimated with a high degree of accuracy. A factor, which is almost unity, is used to correct for the loss of glucose by acid degradation. The method has been applied to potato amylose and amylopecti

ISSN:0022-5142    

DOI:10.1002/jsfa.2740020507

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractAn examination has been made of the significance of several vitamin factors in the production of bracken ‘poisoning’ in ruminants. Bracken feeding led to a rapid cessation of urinary vitamin‐B1 excretion but this was not associated with any consistent increase in pyruvic acid excretion or in blood pyruvic acid concentration. Injections of vitamin B1 given to ruminants showing symptoms of bracken ‘poisoning’ did not produce any recovery. Although bracken‐fed ruminants probably have a subnormal vitamin‐B1status, no evidence was obtained of any acute deficiency.Measurements of blood prothrombin time suggested that no deficiency of vitamin K is involved in the production of this disease, but low body‐reserves of vitamins A and C were found in experimental sheep which had died with brac

ISSN:0022-5142    

DOI:10.1002/jsfa.2740020508

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740020501

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY