952 EXPERIMENT STATION RECORD. 



Of the nitrogen-consuming cover crops sometimes used in orchards, rye and buck- 

 wheat are considered of most importance. Oats are also spoken of favorably in some 

 parts of the country, but have not been satisfacfory when used in connection with 

 crimson clover at the Michigan Station. A mixture of alfalfa, mammoth clover, and 

 turnips, in the proportion of 6 lbs. mammoth clover seed, 10 lbs. alfalfa seed, and 2| 

 oz. of turnip seed per acre, is reported as having given satisfaction as an orchard 

 cover crop. In the cooperative experiments the necessity of preparing the soil with 

 great thoroughness before seeding was demonstrated, as well as the fact that good 

 surface tillage conserves moisture and does much to insure a satisfactory catch of 

 seed. Rolling clover seeded ground has proved an excellent aid to germination. 



Citrus fruit culture, J. W. Mills ( California Sla. Bui. 1S8, pp. 1-38, 42-46, jjh. 

 21). — In this bulletin 12 of the leading varieties of California oranges are described, 

 and a discussion is given of the relative merits of sweet orange, sour orange, and 

 pomelo stocks for oranges, together with general directions for jilanting out orchards, 

 cultivating, irrigating, top-working over old orchards, pruning, diseases, etc. The 

 scales of points used in judging oranges and lemons are also given. 



The Washington Navel, with its subvarieties, constitute the principal oranges of 

 commerce now grown in California. An examination of the root systems of differ- 

 ent stocks resulted in showing that the sweet orange produces a shallow root system 

 with an abundance of fibrous surface-feeding rootlets, thus making trees budded on 

 sweet orange stock especially susceptible to drought. Sour orange stock roots, on 

 the other hand, were found penetrating the soil to a depth of 9 ft., and the laterals 

 were generally more sharply descending. Trees on sour stock do not appear to come 

 into full bearing quite as early as on sweet orange or pomelo stock, but in localities 

 ' where sweet orange stock fails it is thought sour stock will prove especially valuable. 

 In an introductory note by C. H. Shinn it is stated that sour stock is more resistant 

 to alkali than sweet stock, and that the dwarf deciduous orange of Japan {Citrus tri- 

 folinta) is more resistant to alkali than either. The roots of jjomelo stock have been 

 found at a little greater depth than those of sweet orange. It is more fibrous rooted 

 than either stock and is resistant to a certain extent to the root form of gum disease. 

 It has succeeded better at the station than sour stock, and, according to the author, 

 is becoming the favorite stock in southern California. 



The Japanese long-fruited "Cumquat," or gooseberry orange, and dwarf Oonshiu 

 have done especially well at the Sierra Foothill Substation on trifoliata stock, and are 

 recommended for gardens having an elevation of 2,000 ft. 



The Reed system of transplanting is described and illustrated. It consists in thor- 

 oughly watering the trees in the nursery before removing and then lifting them with 

 a large ball of earth attached. The most vigorous trees are used and only the longer 

 branches cut back. The trees are set in holes 2 ft. deep and about 2^ ft. wide. Dirt 

 is then filled in around the roots and settled with water, so that the tree stands at 

 the same height as in the nursery. The ground .should be soaked for several feet 

 around the newly set tree, after which thorough cultivation should follow. AVjoutf 

 lb. of bat guano applied after planting to each tree has been found beneficial. It is 

 mixed with earth and applied in the bottom of trenches on each side of the ball of 

 earth, at right angles to the irrigation furrows and reaching to them. Trees thus 

 transplanted are said to come into bearing one year sooner than by the usual 

 methods. 



In working over old trees the use of "cured" buds is especially recommended. 

 "These are buds that have been cut from the tree and kept in damp sand or moss 

 for a few weeks before using. When treated in this way they become tougher, and 

 when inserted into a tree that has freely flowing sap they absorb it more readily. 

 When buds are well cured, and not allowed to become either too wet or too dry, 

 they are not easily injured in handling." The buds should be wrapped with waxed 

 bands, which are allowed to remain from 4 to 6 weeks. By this time the buds will 



