摘要:

Wheat seed was treated by dusting with a series of seed disinfectants containing 5% of ethyl mercuric halide (80 Br: 20 Cl) and three concentrations of each of KNO3, KH2PO4, NH4KHPO4, and Ca(H2PO4)2∙H2O. This method of applying nutrient salts failed to effect any general stimulation to germination or early growth. In one experiment with Marquis wheat, KNO3accelerated germination without increasing the final value, and all but KH2PO4increased root weight three weeks after planting. In two subsequent experiments with only KNO3added to the mercurial, but with four varieties of wheat, conducted at different temperatures, no stimulation was observe

ISSN:1923-4287    

DOI:10.1139/cjr40c-018

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

With the object of discovering the significance of the "opaqueness" surrounding so-called lipolytic colonies on fat-emulsion agar plates, detailed observations have been made on uninoculated globules of butterfat, pure triglycerides, fatty acids, and mixtures of fats and fatty acids. The following observations have been made:At room temperature, sooner or later, fat crystals form in all butterfat globules. The rapidity with which crystals form and their general conformation and texture are capable of considerable variation. This depends upon the previous history of the butterfat, temperature, and the physical and chemical characteristics of the agar medium in which the fat is suspended.Sodium chloride, among other substances, brings about rapid changes in the form of the globules and the texture of the crystals.The crystals of pure fats suspended in agar are quite unlike the crystals in globules of butterfat. When these same fats are suspended in some form of oily matrix this difference disappears.The chief difference between pure fats and fatty acids, when suspended in oil, is that there is a tendency for the fatty acids to crystallize at the fat-agar interface, while the fats do not. The lower, solid fatty acids often protrude out into the agar medium.As well as copper sulphate and Nile blue sulphate, a large number of other dyes have been used to differentiate fatty acids from fats.It appears probable that the phenomenon of opaqueness in the fat globules surrounding lipolytic colonies in fat-emulsion agar plates is owing, at least in part, to the rapid formation of fat crystals, as well as to the formation of fatty acids.

ISSN:1923-4287    

DOI:10.1139/cjr40c-019

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Samples of 12 varieties of barley from 12 experimental stations in Canada were analysed for starch, barley extract, and crude cellulose plus lignin. Nine six-rowed varieties averaged 3.4% lower in starch, 3.7% lower in extract, and 1.4% higher in cellulose plus lignin than three two-rowed varieties. Maximum and minimum values of the means for the six-rowed varieties were: starch, 55.0% and 52.4%; extract, 77.2% and 74.3%; and crude cellulose plus lignin, 11.3% and 10.1%. Environment had a significant effect. Maximum and minimum values for station means were: starch, 59.2% and 51.7%; extract, 80.8% and 73.6%; crude cellulose plus lignin, 11.0% and 9.6%.Correlation coefficients of carbohydrate fractions with total nitrogen were not significant between varieties but highly significant within varieties for starchr = − 0.95, and extract,r = − 0.91. Partial coefficients, independent of nitrogen between starch and 1000-kernel weight, were significant: between varieties, 0.62; within varieties, 0.75. Those with crude cellulose plus lignin did not attain significance.Starch and barley extract are closely associated within varieties,r = 0.961, and between varieties,r = 0.982. The insoluble cellulose-lignin fraction gave negative inter-varietal associations with starch,r = − 0.952, and barley extractr = − 0.968. Similar relations within varieties are obscured in the simple coefficients but the corresponding partials independent of total nitrogen are significant.

ISSN:1923-4287    

DOI:10.1139/cjr40c-020

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

The transpirational histories of wheat plants, inoculated withBelminthosporium sativumParam., King & Bakke to produce root rot, showed a marked reduction in water loss during the early stages of growth, when compared with uninoculated plants. This was accompanied by a corresponding reduction in the transpiring areas owing to reduced lengths and widths in the second, third, and fourth leaves to appear. As the plants entered into the early stages of elongation of the culm the transpirational story reflected a recovery in the inoculated plants. The later leaves to appear were longer with greater transpiring areas than in uninoculated plants. This fact combined with the death of the first three or four leaves resulted in greater transpirational and photosynthetic areas in the inoculated plants with consequent increased yields of dry matter. Probably similar recovery does not occur under competitive field conditions, where weeds and healthy wheat plants are present. Poor light conditions and low soil moistures were not conducive to recovery of inoculated plants. The water requirements of wheat did not appear to be affected significantly by inoculation. Of two varieties of spring wheat, Reward was more severely injured initially and recovered more rapidly than Marquis. Several possible explanations of the recovery recorded here are discussed.

ISSN:1923-4287    

DOI:10.1139/cjr40c-021

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

A foliage disease of poplar caused bySclerotinia bifrons(E. & E.) Whetzel has been studied during an important outbreak in the years 1935–1937. The perfect stage of this fungus has been correctly named by Whetzel. The fungus hibernates on the ground in the sclerotial condition, and during the spring apothecia are produced on sclerotia. Inoculation of the leaves is induced by ascospores ejected from apothecia. After two or three weeks of incubation, reddish areas appear on leaves; new sclerotia are formed in the lesions in June and are ready to fall about July 15. The epiphytotic development of the disease is favoured by the following set of conditions: presence of a fairly large number of sclerotia on the ground, occurrence of a dense stand of young poplars, low temperature and high humidity before and at the time of foliation. Quite a number of trees at the sapling stage are killed and others are affected by an intense defoliation, during an outbreak. These effects are noticeable only in thickets of pure population of Aspen, which represent usually the first stage of natural reforestation under Quebec conditions.

ISSN:1923-4287    

DOI:10.1139/cjr40c-022

出版商:NRC Research Press    

年代:1940

数据来源: NRC