Numerous bulletins of the agricultural experiment stations and of the United States Department of Agriculture, and books and periodicals relating to garden topics, were consulted during the preparation of the manuscript, and many references are cited throughout the volume. The general plan of the book is in accordance with the recommendations of the Association of American Agricultural Colleges and Experiment Stations. It is hoped that the data gleaned from the author's experience as a commercial grower of vegetables, from a study of many successful market gardens and truck farms, and from the literature of the subject, will be useful to students as well as to practical gardeners.
Most of the photographs were made by the author, although many friends assisted in securing the necessary illustrative material. All the drawings have been prepared by Mr. B. F. Williamson from sketches or photographs furnished by the author. Special acknowledgment is made to the Pennsylvania State College for the use of numerous negatives, and to Professors J. W. Gregg and C. E. Myers of this institution for assistance in making photographs; to Professor L. C. Corbett and Professor W. W. Tracy, of the United States Department of Agriculture, for Figures 82, 84, 90, 93, 94, 95, 100, 102, 103, and 104; to H. B. Fullerton, of the Long Island Railroad Experimental Stations, for Figures 50, 54, 73, 81 and 75; to Professor C. G. Woodbury, of the Illinois Experiment Station, for Figures 87 and 88; to Dr. H. H. Whetzel, of the Cornell Experiment Station, for Figures 62 and 72; to Dr. L. O. Howard, of the Missouri Experiment Station, for Figure 24; to Professor John W. Lloyd, of the Illinois Experiment Station, for Figure 89; to R.'H. Garrahan, Kingston, Pa., for Figure 21; to H. R. Pennypacker, Phoenixville, Pa., for Figure 78; to Lord & Burnham, for Figure 19; to the Skinner Irrigation Co. for Figures 15, 16 and 17; to Robert J. Walton, Hummelstown, Pa., for Figures 55 and 76; to F. J. Zuck, Erie, Pa., for Figure 56; and to J. G. Curtiss, Rochester, N. Y., for Figures 69, 70 and 71.
RALPH L. WATTS.
State College, Pa., 1911.