G50 EXPERIMENT STATION RECORD. [Vol.41 



ducted long enough to determine whether these fertilizers may prove profitable 

 in prolonging the life or bearing vigor of the tree after it otherwise would 

 have begun to decline. 



With one exception young peach trees and apple trees have made much 

 stronger growth and suffered less mortality and have reached bearing age 

 and strength sooner where nitrogen was applied. Blight, however, has dur- 

 ing the past three years been very much more severe on the trees rendered 

 more succulent by the addition of nitrogen. The more succulent trees suffer 

 enough more from blight to offset the greater growth produced by the nitrogen. 



Counts made in the spring of 1918 show that nitrogen is a very important 

 limiting factor in blossom formation upon the tree. The blossoms were 

 numerous on the nitrogen-fed trees but were entirely absent on those receiving 

 mineral salts, although a few of the check trees had an occasional bloom. The 

 nitrogen-fed trees are establishing a splendid stand of fruit spurs, while no 

 such fruit spur development is beginning on check trees or those fed mineral 

 salts. These tests Indicate that available nitrogen is very essential in develop- 

 ing the strength, vigor, and size of young apple trees and in hastening their 

 development to fruiting capacity, whereas no liberal amount of mineral salts 

 is required. 



Spraying investigations conducted by W. W. Lawrence during the year in- 

 dicate that among the arsenicals used to destroy insects that chew and swal- 

 low their food the ortho, neutral, or triplumbic form of arsenate of lead pro- 

 duces the least injury to fruit and foliage, and gives satisfactory results from 

 the control point of view. Lime and sulphur gave the most desirable results 

 for early spraying, while Bordeaux gave better results for late spraying. 



Beport of the Lamao Experiment Station (Philippine Agr. Rev., 12 (1919), 

 No. 2, pp. 80-84, pis. 2). — Brief stateiuents of progress made in the estabUsh- 

 ment of experimental plantings of tropical fruits, citrus fruits, pineapples, 

 avocados, papayas, mangoes, coffee, and root crops, including also data on 

 plant and seed distribution. 



Fruit growing and training, J. Vercier {U Arboriculture Fruiti^re en 

 Images. Paris: Libr. Larousse, 3. ed., pp. 254, fios. 111).— A manual of infor- 

 mation on the culture of various fruits with special reference to training 

 the trees and bushes into special forms. Each fruit is considered with refer- 

 ence to its origin, soil and climatic requirements, planting distance, fruiting 

 period, uses, propagation, methods of pruning, diseases and Insect pests, va- 

 rieties reconunended, and manuring. 



The culture of tree fruits, Gressent (U Arboriculture Fruitidre. Paris: 

 Libr. Agr. de la Maison Rustlque, 1916, 13. ed., pp. 1080, figs. 485).— A treatise 

 on intensive and extensive culture of orchard and bush fruits and crops, in- 

 cluding forcing and nursery practices, together with suggestions for the care 

 of trees in parks, avenues, and forests. 



Orchard management, E. P. Sandsten {Colorado Sta. Bui. 250 (,1919), pp. 

 3-20, figs. iO).— This bulletin discusses the general principles of orchard man- 

 agement, and points out some of the local problems that exist In different 

 localities In Colorado, with suggestions for their solution. 



The commercial apple industry in the United States, J. C. Folger (f7. S. 

 Dept. Agr. Yearbook 1918, pp. 367-378, pi. 1, fig. 1 ) .—This article discusses the 

 commercial phases of the apple Industry, and briefly describes the relative Im- 

 portance of different regions and the factors which Influence their development. 



Keport of division of horticulture, J. P. Pillsbuby (North Carolina Sta. 

 Rpt. 1918, pp. 56, 57). — In the grape-breeding work, hybrids of Vitis rotundi- 

 folia and several other species were secured by using pollen of rotundifolia. In 



