Very frequently young trees are attacked by rabbits, mice, woodchucks and the like and serious damage is done. If the trees are still vigorous and the wounds are not too extensive, the trees may be saved by bridge grafting. When young trees are set in districts where such rodents are numerous, it is a good plan to use some form of a tree protector. These pro tectors may be of wood veneer, wire netting, lath or tar paper. They should be set. into the earth several inches and surround the trunk up to the base of the lower limbs. In milder sections of the South and West, heavy spring frosts sometimes do much damage to the young fruit buds and newly set fruits. In the West particularly,' many large commercial orchards are equipped with fuel pots for burn ing crude oil, distillate and coal, while others use wood. Orchard heating devices are quite common in the citrus regions. The present orchard heating devices are far from perfect and much more must be learned about the range of effectiveness and the limitations of orchard heating before the practice becomes general. They have been more successful when em ployed over a large contiguous area and with fruits bringing high prices than when employed by individual growers and with fruits bringing low prices.
Generally speaking, cultural practices are more highly developed in those regions that are de voted almost entirely to fruit growing and are dependent on long distance markets. The same is true of methods of picking, grading, packing and marketing fruits. It has been thoroughly demonstrated' that careful handling in preparing the fruit for market means a minimum of de cay or deterioration in transit, on the market, or in storage. Also the prompt precooling of carefully handled fruits has a marked influence on their carrying and holding qualities. Compe tition in the fruit trade is keen; hence, fruit that is well grown and given every attention in getting it to the market in good shape must be put up in an attractive manner in order to se cure remunerative prices. The present practice is to put up choice fruits in packages small enough to induce customers to buy by the pack age. This has resulted in so many different sized packages that it has made marketing more or less 'difficult, both for the' dealer' and the consumer. Recent legislation by the Federal gov ernment and by several of the States provides for standard sizes in fruit packagei, whether they be large or small. Fruit especially for apples; have also been established la several States.
The country-wide development of fruit gtow ing has been favored by climate, soil and eco nomic conditions. This growth has also been
fostered by governmental, State and provincial agencies. The Federal and Dominion Depart ments of Agriculture and the various State and provincial agricultural colleges and experi ment stations have contributed largely to the knowledge underlying the commer cial fruit growing. Cultivated fruits have been introduced from foreign countries, varieties have been tested, and cultural problems worked out in experimental orchards. Successful prac tice has been studied in the field with the view of determining the reason for-success and many investigations are conducted in tiamtn*rcial fruit districts in order results may have an immediate practical value. Until very re cently, the cultural phases of fruit growing, re ceived most attention. The ever increasing com petition between different sections' of the coun try has caused the governmental agencies to take up many marketing problems, both tech nical and economic in nature. Many improved practices have resulted' from studies in the handling, precooling, transportation and stor age of fruits. The question of distribution is now receiving attention. The 'Bureau of Markets of the United States Department of Agriculture has an inspection service in most of the large markets for the purpose of investi gating and certifying to shippers the condition and soundness of fruits when received at the market. Information on daily carload move ments of fruit is now available to fruit growers in the commercial areas. See also the articles on the particular fruits.
Bibliography.— The Department of Agri culture of the United States and of Canada as well as the State agricultural colleges and experiment stations have issued numenous bulle tins and reports on the Practical, technical and scientific phases'of fruit growing. Thnagricul tural and general press and private writers have also contributed largely to the •literature of fruit growing. Some of the general works on the subject are Bailey, L. H.,,
New Stand ard Cyclopedia of Horticulture' (6 vols., New York 1914-17) ; id.,