OF SOUTHERN CALIFORNIA. 451) 



function or the presence of the scale. That I incline to the former 

 as the cause, is from the assumed fact that tlie accumulation of dust 

 and filth upon the leaves, remaining undisturbed for a brief or 

 indefinite period, must seriously interfere with the solar influence 

 upon the chemical processes going on therein. And this alone by 

 returning unelaborated sap as nutriment to the whole tree, might 

 account for its tardy growth and sickly appearance. And then again, 

 should the roots be struggling in uncongenial soil, or if, on the con- 

 trary, the soil is found entirely compatible, injudicious treatment 

 might prove equally injurious to the free play of functional energy. 

 These must be regarded as definite causes of derangement, and the 

 latter especially as a fundamental cause of a form of plant dyspepsia. 

 Under such a condition of things, instead of the roots being able to 

 contribute to plant life and health by a reciprocity with the leafy 

 foliage, they can only serve to increase the existing complications 

 and general derangement. 



That the scale-infested tree almost entirely ceases to grow left to 

 itself with but the ordinary culture, is too apparent to call s])ecial 

 attention thereto. And it is also equally apparent that before the 

 scale has made much progress in possessing the tree, the greater por- 

 tion, if not the entire surface, will be found grim with the exudation 

 before mentioned, dust and fungus. 



Later in the progress of the parasite and disease, excrescences, both 

 from insects that prey upon it, and the scale itself, will rapidly accu- 

 mulate and thickly spread over leaf and branch in a short space of 

 time. To arrest this is the first object, and for this accomplishment 

 nothing but a thorough renovation by the cleansing process will pro- 

 duce the desired result. Thus freed from these foreign accumula- 

 tions with a trimming away of all unnecessary inner twigs and hlth 

 receptacles, a slitting down of the stem bark on the shady side, with 

 the addition of potash in the form of wood ashes, or of unslaked lime 

 about the roots, i. c, upon the surface of the ground about the tree, if 

 in a sandy or gravelly loam, will speedily liberate the imprisoned 

 functions, and new life and vigor will at once appear in an abund- 

 ance of a rich and healthy foliage. In the adobe, clay, or heavily 

 inclined and therefore naturally cold soil, a liquid fertilizer from the 

 barnyard should be applied to the roots and a generous mulch of tlie 

 coarse yard accumulations subsequently spread over the entire root 

 surface of the tree. It is understood, however, that the application 

 of these fertilizers should precede the washing, in order to permit the 

 water to do double duty of cleansing the top and at the same time 

 facilitate the fertilizers in penetrating the soil. The above treatment, 

 if thorough, will prove entirely satisfactory in every respect. 



I presu.me this or a similar course has been pursued by the majority 

 of orange orcliardists heretofore, but it may be a question whether it 

 was adopted with a special or a double object in view. The use of a 

 small jet of cold water under a pressure of twelve feet or more, acts 

 mechanically in disengaging the scale and all adhering substances, 

 and also as a detergent, but will not accomplish the full purpose of 

 cleansing and invigorating the tree that is desired, in the woi'st forms 

 of the disease and presence of scale, unless often repeated during a 

 growing season, and also during the dormant stages of the tree. If 

 this course is pursued, nothing else will be required to bring the tree 

 up to a healthy standard. 



Much more of interest bearing upon the insect plague of our orange 



