ISSN:0022-5142    

DOI:10.1002/jsfa.2740031101

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

Abstract1. A soil compactometer with an automatic recording device has been described. It is portable and adaptable to spacings of 6 and 9 inches between the rows, and gives satisfactory results with soils varying from very light to heavy resistances to penetration.2. A survey of the compactometers and penetrometers and their uses has been made. The speed of penetration of the instrument into the soil is considered in relation to the design of machines for accurate measurements.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740031102

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractExperience has shown that a low moisture content in the seed is essential for satisfactory expression of the oil. The greater size of tung seed compared with other oil seeds led to experiments with both whole seeds and disintegrated meal, but similar conclusions were reached with both types of feed. Determination of the equilibrium moisture contents of tung seed under the usual atmospheric conditions of Nyasaland showed that the accepted estate methods of harvesting could be improved, resulting in higher yields of oil being expressed from the seed.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740031103

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractThe effect of the presence of free fatty acids on the gelation characteristics of tung oil has been examined by several workers since 1920. They used the different heat tests current at the time and also limited their observations to samples of commercial oils. These were Chinese oils derived fromAleurites fordiior possibly mixed oils from bothA. fordiiandA. montana.The predominance of theA. montanaoil in Nyasaland has led to a closer study of the effect on this oil. It has been found that the same concentration of free fatty acid produces a greater delaying action on the gelation of this oil than is caused on that from theA. fordiispecies. The B.S. heat test was used for the comparison.A consideration of recent investigations into the composition of drying oils affords an explanation of these results.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740031104

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

Abstract1. A study of the effects of cultivation on root development of winter wheat was made in two Midlothian soils, Boghall and Corstrophene, during the years 1945–46 and 1946–47. Cultivation treatments consisted of ploughing to a depth of 8 in., deep cultivation (4 in.) and shallow cultivation (2 in.) with a tined cultivator.2. Ploughing to a depth of 8 in. loosened the soil of the ploughed plots in the 4–8‐in. layer and increased the non‐capillary porosity of the soil (aeration) in this layer compared with the 4‐in. and 2‐in. tine cultivations. No significant differences existed between the treatments in respect of looseness of soil or its non‐capillary porosity at depths of 0–4 in.3. The effects of cultivation on root development were more pronounced at the later stage of growth in July than at the early stages. Compared with time cultivation, ploughing increased the number and lengths of roots at all depths in July, but only at the 10–20‐cm. depth in the early stage of growth. No significant differences existed between the treatments in respect of average vertical root penetration at the early stages of growth. A deep root system with a large number of roots and with profuse branching developed after ploughing, and a shallow root system with a comparatively smaller number of roots and with sparse branching followed tine cultivation.Increased non‐capillary porosity of the soil at a depth of 10–20 cm. and the richer condition of the soil at this depth (formerly the upper layers, now inverted by ploughing) probably contributed to the greater root development in the ploughed plots at the early stage of growth, and presumably in July.4. The degree of branching was affected by the depth of cultivation. Ploughing to a depth of 8 in. induced a higher degree of branching at 10–20‐cm. and 20–30‐cm. depths than did working the soil to 4 or 2 in. with a tine cultivator. Root branching of the second and third order occurred predominantly at depths below 10 cm., and that of the first order predominated at the 10‐cm. level. The poorer conditions of soil moisture in the upper layers probably limited the degree of branching in these layers.5. In the humid and rich soil of Boghall, a shallow root system of wheat developed, the majority of roots (74%) being in the 0–8‐in. layer. Ploughing to 8 in. extended the spread of roots in the deeper layers of the soil in horizon A2 (8–12 in.), but restricted it in the upper layers of soil in horizon A1 (0–8 in.). It is doubtful if deepening the working depth of roots by ploughing in a rich soil offers any advantages over the 2–4‐in. cultivations from the view point of water and nutrient supply.6. At the early stages of plant growth top/root ratio in crop weight as well as in surface area was smaller with the 2‐in. tine cultivation than with ploughing or 4‐in. cultivation. No such differences existed between the treatments after manuring. A deficiency in the supply of nitrog

ISSN:0022-5142    

DOI:10.1002/jsfa.2740031105

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractThe synthesis of a number of compounds likely to possess fungicidal activity has been described by the authors in the earlier papers of this series (Sen&Joshi, 1948, 1949, 1951a, b). This paper incorporates the results of an investigation of the fungicidal action of 55 of those compounds on the fungusAspergillus nigeremploying the agar‐growth technique. The results have been reviewed with the idea of correlating chemical constitution and fungicidal activity in the light of theories put forward by various authors from time to time. As expected, most of the compounds tested have been found to be considerably toxic to the fungus. Interesting results have been obtained with aryloxy‐fatty acids, which stimulate growth at lower concentrati

ISSN:0022-5142    

DOI:10.1002/jsfa.2740031106

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractSamples of urea‐formaldehyde materials, prepared by various methods, have been tested in the laboratory with reference to their possible use as nitrogenous fertilizers. In particular the rate and extent of mineralization of the nitrogen of urea‐formaldehyde products in soil has been investigated in relation to the ratio of urea to formaldehyde initially present in the reaction mixture. The product from equal molar quantities of urea and formaldehyde is almost insoluble and inert in the soil, but the proportion of soluble and available nitrogenous constituents in these substances increases markedly with the urea/formaldehyde ratio of the reactants. Soil tests show that urea‐formaldehyde samples can be prepared which closely resemble natural products such as hoof and horn in their rate of decomposition in the soil. The high degree of availability of the nitrogen of these materials expected in view of their low carbon/nitrogen ratios has not, however, been observed in the present work, unless the water‐soluble nitrogen in the products was high. The form of the curves for mineralization of nitrogen in the soil is discussed in relation to the contents of free urea and water‐soluble nitrogenous constituents, and to the conditions of preparation of th

ISSN:0022-5142    

DOI:10.1002/jsfa.2740031107

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractAn investigation has been carried out to evaluate the common brown algae indigenous to Great Britain as a source of alginate. In particular, the viscosity of the sodium alginate from each species has been examined, and the effect on the viscosity of drying and bleaching has been studied. In an attempt to show that the alginates from the different species are essentially the same, specific rotations have been determined.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740031108

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractDried skimmed milk is generally considered to be a desirable ingredient of chick diets; this opinion is reflected in the present Ministry of Food Regulations, which require that Baby Chick Mash shall contain at least 6% of dried skimmed milk, except that it is permissible to replace each 1% of dried milk products by 1/2% of unextracted dried yeast. In view of the scarcity and high price of both of these materials, an investigation was carried out to determine the effects of reducing the level of dried skimmed milk in a Baby Chick Mash and substituting varying amounts of a riboflavin supplement.The results obtained indicate that, under the conditions of these experiments, the level of dried skimmed milk may be reduced to 3% of the diet, or omitted entirely, without significantly affecting growth rate, food consumption, feathering, or general health of the chick up to 10 weeks of age, provided that adequate riboflavin supplement is added to the mash.The chicks receiving neither dried skimmed milk nor riboflavin supplement in their diet showed a somewhat poorer growth‐rate which was particularly evident in both experiments at 5–6 weeks of age. However, the difference in mean body weight between chicks on this basal diet and the other groups was only significant at 6 weeks of age in the second experiment. In general, feathering was poorer and mortality higher among the birds receiving the diet with neither dried skimmed milk nor riboflavin supplement.In both experiments there were indications that dried skimmed milk was most effective during the first six weeks of the chick's l

ISSN:0022-5142    

DOI:10.1002/jsfa.2740031109

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractInterference by ferrous iron in the determination of ascorbic acid in canned foods can be eliminated by passing an oxalic acid extract through the cation‐exchange resin Zeo‐Karb 215.This method has given satisfactory results when tested on a number of canned food products. The average recovery of pure ascorbic acid added to extracts of iron‐contaminated canned foods was 97%, and the results showed less scatter than those obtained by another method. With citrus juices that were deliberately contaminated by iron, recovery of the natural ascorbic acid was not less than 95%.Results obtained by this method for the ascorbic acid contents of canned foods were generally in good agreement with those obtained on the same samples by another method based on a different prin

ISSN:0022-5142    

DOI:10.1002/jsfa.2740031110

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY