Collection: Directories and Documents > Pamphlets

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Title: Report on the Agriculture Experiment Stations of the University of California (PH 4-16)(1890) Collection Type: Directories and Documents Collection Name: Pamphlets Catalog #: PH 4-16 Author: E.W. Hillgard Published: 1890 # of Pages: 211 Download PDF: User Login Required Download OCR Text: User Login Required

Printed or handwritten: All printed text Date Scanned: 2024-10-31 16:19:15 Scanned By: Shelby Figueroa Scanning Equipment: CZUR Book Scanner OCR Software Version #: tesseract 5.4.1 Item Sourced From: JPGs First Created: 2025-03-17 05:48:55 Last Updated: 2025-03-17 05:48:55

Original Held At: Searls Historical Library Location: 161 Nevada City Hwy, Nevada City, CA 95959

Page: of 211  

CENTRAL EXPERIMENT STATION. 23 MrtrorontoGy or OAKLAND—Continued. 1882, 1883. 1884, 1885, 1886, 1887, 1888. Mean temperature of spring -----.----54.12 . 54.63 . 55.59 . 58.08 . 55.06 . 55.29 49.39 Mean temperature of summer ---.--.60.06 . 61.16 . 61.89 . 61.23 . 61.60] 60.29} 55.52 Mean temperature of autumn-56.44 . 54.25 . 57.07 . 59.52 . 56.89] 56.85 62.29 Mean temperature of winter --46.80 . 46.20 . 47.38 . 51.69 . 52.12] 49.80 59.30 Maximum temperature ---._-_. 84.00 . 103.00 . 88.00} 89.00 . 91.00 . 101.00 91.00 Minimum temperature --..-.-..--30.00} 25.00 . 28.00 . 27.00} 30.00] 31.00 26.00 Mean relative humidity. .-.---.-----82.57 . 83.71 . 85.39 . 86.74 . 87.15] 88.53 . 85.83 Lowest relative humidity --.----._---. 2870} 33.90} 38.19} 41.50} 26.70 . 41.50 56.70 Rainfall, July to following June-.----18.13 . 20.22} 31.10] 17.95} 32.21} 18.45 17.10 These records show clearly the leading characteristics of the climate under which culture experiments are made at the Central Station. Seasonal temperatures are very equable. The variation between the coldest and warmest months of the years cited has ranged from 12 to 17 degrees. At no time has the mercury fallen more than 7 degrees below the freezing point, and has reached this depression but once, while the usual minimum temperature is but 3 degrees below freezing. Thus only very tender plants are winter-killed. In fact, the prevailing low summer temperature more seriously limits the adaptability of the location to experimental fruit cultures than does the cold of winter. Fruits bloom approximately at the same date as the same varieties in the hot interior valleys, but so tardy is the growth under the low summer temperature that these varieties ripen a month or more later than in the interior, or, as in the case of late-ripening varieties, do not reach perfection at all. The same is true of other plants and trees which require high summer heat to secure large growth or excellence in fruitage. On the other hand, plants adapted to comparatively cool, moist air may thrive in Berkeley and utterly perish in the interior. As the table shows, the atmospheric humidity sinks to a loy minimum each year; but this condition prevails but for a few days at a time, while a dry, north wind is blowing; and plants which show distress (by curling of leaves, etc.) during this period, generally recover quickly under the influence of a current of moist air, which flows in from the ocean as soon as the north wind is stayed. For this reason some plants thrive here which would not survive the continued heat and drought of some interior points which perhaps do not show a lower minimum humidity. . Thermal Belts—Among the climatic peculiarities belonging more or less to the whole State, but more especially pronounced in the valleys opening toward the bay, is the occurrence of “thermal belts,” or minor regions exempt to a remarkable degree from the severer frosts of winter, but more especially from the later ones of spring, which are so dangerous to fruit about the time of bloom. These usually occur between one hundred and eight hundred feet above the valleys, varying of course with the trend and exposure to the coast winds. The difference in temperature at sunrise between these belts and the valleys sometimes amounts to as much as 10 degrees F., which, in a region where the thermometer rarely falls below 26 degrees, of course implies a very material difference in the chances of such fruits as almonds, apricots, and even the vine, and in many cases Regs of the successful culture of semi-tropical fruits, such as the orange, emon, pomegranate, etc. Thus the latter are successfully grown (e. g., in certain valleys near Martinez, Contra Costa County) within two miles of the cold blast that sweeps through Carquinez Straits. Similar cases are frequent in the valleys of Napa and Sonoma; a very striking example is