摘要:

An analysis of the monthly sequence of mean temperature during the summer period, April–September, of the years 1894–1937 has been made by expressing each annual sequence as an orthogonal polynomial function of time. Whereas the precipitation sequence, previously studied, required terms of the fourth or fifth degree for its adequate representation, the average temperature sequence at all three stations was very closely approximated by a third degree polynomial. On the average, corresponding coefficients for each station differ significantly, indicating decreasing continentality of the temperature regime with distance westward from Winnipeg. Annual variations in corresponding coefficients for the three locations are appreciably correlated, but for the most part exhibit no regular sequence in time. However, in recent years at Edmonton the mean temperature for April has tended to be lower, and that for July and August to be slightly higher, than previously. There is some suggestion of a feeble inverse correlation in the annual fluctuations of temperature and precipitation.

ISSN:1923-4287    

DOI:10.1139/cjr41c-045

出版商:NRC Research Press    

年代:1941

数据来源: NRC

摘要:

Apple trees of the McIntosh Red variety were sprayed at about the time of full bloom in 1939 and 1940. The origin and structure of the resultant russet tissue is described. The first apparent injury is a browning of the epidermal cells at the base of the hairs. The growth of these browned cells is inhibited and, owing to this, cracks occur as the fruit enlarges. Adjacent hypodermal and cortical tissue is exposed and killed. Cork cambiums and cork are formed in the cortex. This cork is different in origin from normal russet cork, which originates in the epidermis. The further enlargement of the fruit causes the cracks to multiply, extend tangentially, and deepen. All tissues external to the innermost point of fissure penetration become killed. The final scurf-like patches of scar tissue are a mixture of dead epidermis, hypodermis, cortex, cork, and cork cambiums. This scar tissue is not true cork.

ISSN:1923-4287    

DOI:10.1139/cjr41c-046

出版商:NRC Research Press    

年代:1941

数据来源: NRC

摘要:

When a mature green tomato fruit is stored at 12.5 °C. either with or without its stem, the expected respiratory climacteric accompanies the colour change associated with ripening. When the stem is removed and the stem scar area is covered carefully with hot paraffin wax, the fruit thereafter ripens slowly with a low, relatively constant rate of carbon dioxide output. These characteristics are ascribed to "auto-gas" storage resulting from restricted diffusion at the stem scar. The effect of waxing is reversible within limits since removal of the artificial seal after one month has resulted in a return to normal ripening and respiratory behaviour.When yellowing, yellow orange, and full red fruits are stored either with or without their stems, they complete in storage those phases of the respiratory climacteric that had not been completed before detachment from the plant. The careful waxing of fruits picked at these stages of maturity inhibits further coloration and reduces the rate of carbon dioxide output to the same extent as in fruits waxed at the mature green stage. The respiratory drift of fruits picked and stored unwaxed at the early "growing green" stage is characterized by two distinct peaks. Such fruits eventually ripen and the second peak is associated with the colour change that accompanies ripening. Similar fruits stored with stem scars waxed fail to ripen before their pathological "death" and their respiration rate is reduced by the waxing treatment.When yellowing and yellow-orange fruits are waxed, they become soft and highly susceptible to fungal attack before their ripening coloration has been completed. To inhibit the softening process in stored tomatoes, it thus appears to be necessary to apply wax before ripening has commenced. Unwaxed fruits become highly susceptible to fungal wastage only after attaining full ripeness. Waxed fruits on the other hand are subject to fungal wastage when green or partially coloured as well as when fully ripened. This is attributed to the progress of softening in the absence of the usual colour change associated with ripening. Waxing of the stem scars does not act as a deterrent to storage moulds at the waxed area. The waxed tomato has been found to be subject to several physiological disorders the symptoms of which are described.

ISSN:1923-4287    

DOI:10.1139/cjr41c-047

出版商:NRC Research Press    

年代:1941

数据来源: NRC