One Thousand Questions in California Agriculture Answered By E. J. Wickson Professor of Horticulture, University of California; Editor of Pacific Rural Press; Author of "California Fruits and How to Grow Them" and "California Vegetables in Garden and Field," etc. Foreword This brochure is not a systematic treatise in catechetical form intended to cover what the writer holds to be most important to know about California agricultural practices. It is simply a classified arrangement of a thousand or more questions which have been actually asked, and to which answers have been undertaken through the columns of the Pacific Rural Press, a weekly journal of agriculture published in San Francisco. Whatever value is claimed for the work is based upon the assumption that information, which about seven hundred people have actually asked for, would be also interesting and helpful to thousands of other people. If you do not find in this compilation what you desire to know, submit your question to the Pacific Rural Press, San Francisco, in the columns of which answers to agricultural questions are weekly set forth at the rate of five hundred or more each year. This publication is therefore intended to answer a thousand questions for you and to encourage you to ask a thousand more. E. J. Wickson. Contents Part I. Fruit Growing Part II. Vegetable Growing Part III. Grain and Forage Crops Part IV. Soils, Irrigation, and Fertilizers Part V. Live Stock and Dairy Part VI. Feeding Animals Part VII. Diseases of Animals Part VIII. Poultry Keeping Part IX. Pests and Diseases of Plants Part X. Index Part I. Fruit Growing Depth of Soil for Fruit. Would four feet of good loose soil be enough for lemons? Four feet of good soil, providing the underlying strata are not charged with alkali, would give you a good growth of lemon trees if moisture was regularly present in about the right quantity, neither too much nor too little, and the temperature conditions were favorable to the success of this tree, which will not stand as much frost as the orange. Temperatures for Citrus Fruits. What is the lowest temperature at which grapefruit and lemons will succeed? The grapefruit tree is about as hardy as the orange; the lemon is much more tender. The fruit of citrus trees will be injured by temperature at the ordinary freezing point if continued for some little time, and the tree itself is likely to be injured by a temperature of 25 or 27° if continued for a few hours. The matter of duration of a low temperature is perhaps quite as important as the degree which is actually reached by the thermometer. The condition of the tree as to being dormant or active also affects injury by freezing temperatures. Under certain conditions an orange tree may survive a temperature of 15° Fahrenheit. Roots for Fruit Trees.