摘要:

When runner-grafted to domestic plants of the strawberry varieties Premier and Glen Mary (symptomless carriers of the virus of yellow-edge) clones of the common wild strawberry,Fragaria virginianaDuchesne, were found to vary widely in their resistance and susceptibility to the disease. Certain clones of noticeably more delicate growth type, proved to be very highly susceptible to deterioration and exhibited complete symptom-expressing propensities. Other clones, characterized by a particularly robust type of vegetative growth, although readily susceptible, showed capacity for at least partial recovery, tending to react more like the English indicator variety, Royal Sovereign. Still other clones, also of the robust type, showed resistance that was virtually complete; thus they were eliminated from plants of the "carrier" class.

ISSN:1923-4287    

DOI:10.1139/cjr41c-027

出版商:NRC Research Press    

年代:1941

数据来源: NRC

摘要:

Inter- and intravarietal relations between malt extract and barley properties (extract, starch, total nitrogen, 1000-kernel weight, salt-soluble nitrogen, saccharifying activity, cellulose-lignin residue, and steeping time) have been investigated by developing prediction equations for malt extract.The most useful single factors for intervarietal prediction are barley extract, starch, and cellulose-lignin residue, in the order given. The inclusion of salt-soluble nitrogen and steeping time, as additional independent variables, with barley extract or starch, results in a significant improvement in the level of prediction. The most accurate equation was:malt extract = 1.1 + 0. 93barley extract + 7.44salt-soluble nitrogen− 0.035steeping time. This equation serves to indicate the relative extract yield of varieties grown at the same station, the standard error being ± 0.8%. The constant, 1.1, varies from station to station; hence, although this average value gives relative extract yields, the constant must be evaluated for specific environments if absolute extract yields are required.The most useful single factors for intravarietal prediction are barley extract, starch, and total nitrogen. Statistical analysis showed that only barley extract and total nitrogen could be effectively combined for prediction purposes. The equation is:malt extract = A + 0. 58barley extract− 2.4total nitrogen, standard error ± 0.6%. The factorAis dependent on variety but the data suggest that for Canadian malting varieties this constant has a value of about 35.7.Attempts to develop a generalized equation applicable to all samples, irrespective of varieties and the environment in which they were produced, proved unsuccessful. This is apparently due to significant differences between the inter- and intravarietal partial regression coefficients for the properties studied.

ISSN:1923-4287    

DOI:10.1139/cjr41c-028

出版商:NRC Research Press    

年代:1941

数据来源: NRC

摘要:

The methods used for the isolation and study of film-forming yeasts are described. Two of these methods are of special interest, viz., the observation of the structure of pseudomycelium on "cross-hatched" plates and the preparation of gypsum cultures in test tubes.

ISSN:1923-4287    

DOI:10.1139/cjr41c-029

出版商:NRC Research Press    

年代:1941

数据来源: NRC

摘要:

Norway spruce cuttings were collected at intervals throughout the year, subjected to treatment with talc dusts containing from 5 up to 10,000 p.p.m. of indolylacetic acid, and propagated in outdoor frames. In some experiments, indolylacetic acid treatments were included in a series of dusts involving cane sugar, potassium acid phosphate, and organic mercurial disinfectants. Effects of wax coating of cuttings of Norway and white spruce and eastern white cedar were also considered.Indolylacetic acid treatment failed to have any general beneficial effects on rooting; concentrations of 8000 and 10,000 p.p.m. were usually injurious. However, treatment of apparently dormant cuttings, taken shortly before emergence of new growth, with 1000 p.p.m. gave 25% rooting, as compared to 8% for the controls, and tended to increase the length of root. Treatments with organic mercury, cane sugar, and potassium acid phosphate increased survival of new growth, and, in combination with indolylacetic acid, increased survival and root lengths.Talc treatment increased rooting to as much as 70% for cuttings planted in sand as compared to 25% for the controls, but had no effect on plantings in a sand–peat mixture. Talc effects were the most marked on cuttings taken before emergence of new growth and when planting was delayed for 24 hr. after treatment.Wax application had no effect on dormant spruce cuttings but was markedly injurious to summer collections. Injurious effects were reduced when wax was used in conjunction with indolylacetic acid treatment.

ISSN:1923-4287    

DOI:10.1139/cjr41c-030

出版商:NRC Research Press    

年代:1941

数据来源: NRC