2380 



ORAXCIE 



ORCHIDS 



scales are most damaging along the coast, while the red 

 and yellow are severe in the interior valleys as well as 

 the coast country. In Tulare County, a species of 

 thrips has done much damage by scarring the fruit 

 and distorting the leaves. The Tortrix worm is the 

 only insect which burrows into the orange. 



Gum disease is the most serious fungous disease of 

 the tree in California, while armillaria root-rot, mal- 

 di-gomma, trunk-rot (Schizophyllum), twig-blight (Scle- 

 rotinia), wither-tip (Colletotrichum), and damp-off 

 fungi are minor troubles. Physiological diseases of the 

 tree include squamosis or scaly bark, exanthema, chlo- 

 rosis, mottled-leaf, die-back, and leaf-gumming. Fun- 

 gous diseases of the fruit are : brown-rot (Pythiacystis 

 citrophthord), blue-mold (Penicillium italicum), green- 

 mold (Penicillium digitatum), gray-mold (Botrytis vul- 

 garis), sooty-mold (Melilola Camellise), cottony-mold 

 (Sclerotinia sp.), gray scurf and navel end-rot (Alter- 

 naria citri). 



Physiological defects of the fruit are: sunburn, frost, 

 off-bloom, exanthema, corrugations, bottle-neck, fin- 

 gers, yellow-spot, double navel, brown-spot, stem-end 

 spot, cracks, puffs, splits, peteca, red-blotch, and others. 



Control measures, more or less satisfactory, have been 

 worked out for the larger number of insects and dis- 

 eases prevalent in the state. 



Protection against frost. 



The different kinds of citrous fruits vary in the 

 amount of cold they will endure without injury. The 

 amount of injury done by a given degree of cold upon a 

 given variety will vary, also depending upon the degree 

 of dormancy, the state of the weather just preceding 

 and just after the freeze and the length of time the 

 cold lasts. Many thousand acres of land in California 

 are well suited for growing citrous fruits except for the 

 fact that they are subject to occasional frosts which 

 destroy the crop and sometimes injure the trees. It is 

 natural, therefore, that under such conditions, the 

 citrous growers of California should be pioneers in 

 the work of frost-protection. A great deal of experi- 

 menting has been done along the line of diminishing 

 the radiation of heat and by raising the dew-point. 

 It has been demonstrated, however, that the most 

 practicable and satisfactory method of fighting frost 

 is by adding heat directly to the trees through the 

 agency of fires distributed throughout the orchard. 

 Some ten or more types of patent orchard-heaters 

 are now on the market, but the kind the citrous 

 growers find most satisfactory is a round sheet-iron 

 pot of three or five gallons capacity fitted for burning 

 low-grade distillate or crude-oil. The pot should be 

 provided with a suitable cover to keep out the rain and 

 a draught by which the size of the flame may be regu- 

 lated to suit the degree of cold to be overcome. The 

 less smoke is produced, the better. The smudge com- 

 monly used by deciduous fruit-growers is objected to 

 on the ground that the fruit is covered with soot and it 

 is both expensive and damaging to the keeping quality 

 of the fruit to clean it properly. Citrous growers prefer 

 to generate the additional amount of heat necessary 

 to compensate for the lack of smoke. 



Many small fires are better than a few large ones. 

 The heaters are usually placed one to each tree or 

 about ninety to the acre throughout the orchard with 

 an extra row along the windward sides. Each ranch 

 should be provided with an oil-reservoir which will 

 hold enough oil to fill all the heaters on the ranch five 

 or six times. When properly equipped with heaters, 

 the temperature of an orchard can be maintained dur- 

 ing the night at 10 F. above that of the surrounding 

 country. 



The effects of frost on oranges appear as a spotting 

 of the skin and a softening of the outward side of 

 exposed fruits. The juice disappears, leaving the 

 interior dry and pithy. Slightly frosted oranges occa- 



sionally develop a very bitter taste. Fruit from the 

 same trees will often grade all the way from sound to 

 badly frosted, depending on the position the fruit 

 occupied on the tree. The method of separating sound 

 from frozen fruit is based on specific gravity. 



The machine consists of an oblong tank through 

 which water may be made to circulate at definite speeds 

 by a small propeller. The oranges roll down an incline 

 and drop into the moving water from a height of a foot 

 or more. The light frosted oranges bob up to the surface 

 quickly, while the sound, heavy fruit is slower to rise. 

 Meanwhile the oranges have been carried along by the 

 current, the sound fruit passing under, and being caught 

 by a horizontal wire screen, while the light fruit is car- 

 ried along above it. At the farther end of the tank the 

 two grades are lifted by conveyors and delivered to 

 separate bins. By adjusting the position of the screen 

 and the rate of flow of the water, any degree of separa- 

 tion desired may be secured. 



By-products. 



The manufacture of citrous oils, perfumes, citrate of 

 lime, and other by-products has never been developed 

 commercially in California, although at present much 

 experimenting is being done in an effort to encourage 

 such an industry, which is badly needed. At present, 

 the culls mostly go to waste or are applied to the land as 

 fertilizer. The manufacture of marmalade and citrate 

 of lime has been attempted but has not as yet assumed 

 importance. j ELIOT COIT. 



ORANGE, OS AGE: Madura. 



ORANGE ROOT: same as goldenseal, Hydrastis canadensis. 



ORCHARD. In North America, the word orchard 

 is applied to a plantation of fruit-trees. The orchard is 

 one part of the typical American farmstead, comprising 

 either a few trees for domestic supply in a regularly 

 laid-out plantation or a larger area planted as a source 

 of revenue. Commercial plantings of large extent are 

 also made without particular reference to a homestead. 

 Except in the warmer parts, the apple tree comprises 

 the usual orchard planting. Plantations of bush-fruits 

 are not known as orchards in this country. By custom, 

 orchards of citrous fruits are usually called groves. 



ORCHARD-GRASS: Dactylis glomerata. 



ORCHARD HOUSE, a name frequently used in Eng- 

 land for glasshouses devoted to fruit-trees. Consult the 

 article on Forcing of Fruits , volume III, page 1260. 



ORCHARD PROTECTION: See article on Frost. 



ORCHIDS. A vast assemblage of herbaceous plants, 

 mostly with unusual and interesting flowers, of which 

 about 15,000 species are at present known. This num- 

 ber is being augmented yearly as the regions which they 

 inhabit become more accessible to collectors. A single 

 collection in New Guinea in 1907 to 1909 brought to 

 light 1,102 new species, an indication of the number 

 of new forms still to be expected from little-explored 

 regions. Since the first edition of the "Cyclopedia of 

 American Horticulture" was published, the number of 

 known species has been increased by about 5,000. 

 Probably the species now outnumber those of the great 

 family Compositae. 



Although widely distributed, the orchids are seldom 

 abundant in any place as to individual plants. They 

 are mostly inhabitants of special or particular places. 

 Orchids are also highly specialized in structure, particu- 

 larly in character of flowers, in this differing widely 

 from the broadly generalized structure of the Com- 

 positae. 



These very special plants, with marvelous range of 

 form and color, have naturally excited the greatest 



