摘要:

A rapid refractometric method for the estimation of the iodine value of freshly prepared linseed oil is described. This involves expression of the oil at laboratory temperature from finely ground flaxseed, determining the refractive index at 25 °C. and converting to Wijs iodine value by means of the regression equation expressing the relation between these variables. In a study of cold pressed linseed oils prepared from 339 samples of sound Canadian flaxseed varying in Wijs iodine value from 153 to 202 units, a correlation of 0.980 between refractive index and Wijs iodine value was found which permits the estimation of iodine value with a standard error of prediction of 2.1 units.Ethyl ether extracts obtained by the usual extraction procedure for determining oil content are not recommended, owing to differences in the characteristics of the oil and a lower degree of association between refractive index and iodine value.Since the refractive index of linseed oil and its relation to iodine value are influenced by free fatty acids, oxidation and polymerization, the method is not applicable to commercially prepared oils nor to flaxseed which has heated or become musty.The method is considered sufficiently accurate for surveys of the quality of flaxseed produced in different districts and of new varieties and hybrids submitted by plant breeders. It should also prove of considerable utility to linseed crushers for securing a measure of the intrinsic drying value of their raw material.

ISSN:1923-4287    

DOI:10.1139/cjr37c-027

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

Data from 21 varieties of flax, grown at the Central Experimental Farm over a five-year period, were analyzed statistically to determine the relation of quantity and quality of oil to seed size, days to maturity, days from flowering to maturity, and height of plant. In addition, hybrids of Cyprus × Ottawa 770B and Buda × Ottawa 770B were studied to determine the genetic basis for the inheritance of quality of oil, flower type, color of seed, color of oil, seed size and height of plant.The refractometric method for determining the quantity and quality of oil was compared with the ether extraction method for oil content and the Wijs method for iodine number and found to be very practical for breeding studies.In the variety test, high oil content was associated with a long period from blossoming to maturity and with large-seeded varieties.In the hybrids, iodine number, seed size, and height of plant are apparently dependent on several genetic factors. No significant association between oil content, iodine number, seed size or height of plant was found among these hybrids. The inheritance of flower and seed type has been explained on the basis of a single factor, the Ottawa 770B type with white, narrow, involute petal and greenish-yellow seed being inherited as a simple recessive or the expression of several very closely linked recessive genes. An association of high iodine number with this factor for yellow seed color was indicated in both hybrids.Although insufficient data were collected to give definite conclusions, evidence indicated that color of oil, as measured by carotinoid pigment content, had a genetic basis. No correlation was indicated between carotene pigment content and the quantity and quality of the oil or color of the seed.

ISSN:1923-4287    

DOI:10.1139/cjr37c-028

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

Chemicals applied to annual weeds frequently gave dosage-mortality curves that were not of the usual sigmoid shape. These departures appear to be attributable to the method of application, as the spray is only partly retained by the leaves and stems. The proportion of the applied quantity of poisonous constituent retained by the plant decreases as the volume of spray is increased, and increases as the concentration of the spray solution is increased. Leaf sprays will therefore be most effective if the minimum volume of solution required for coverage is used, and the effective dosage of the chemical obtained by adjusting the concentration.A few indices sometimes used for estimating the efficacy of herbicides were compared with the mortality criterion. The number of leaves left, and the height of the living plants after treatment are of little or no value for estimating the effect of the chemical. The weight per unit area of the living plants remaining after treatment may be of some value.

ISSN:1923-4287    

DOI:10.1139/cjr37c-029

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

The development of the four protective layers of the apple, namely the hairs, cuticle, epidermis and hypodermis, is described in detail, from the time the flower emerges from the winter bud early in May, until harvest time early in October. The gradual loss of living and active cell contents is recorded for each layer. Measurements of cuticle thickness for the period of the study are listed and an approximate date is given for each stage of development. The descriptions of tissue morphology are supplemented by ten illustrations.

ISSN:1923-4287    

DOI:10.1139/cjr37c-030

出版商:NRC Research Press    

年代:1937

数据来源: NRC