BULLETIN 153. 



FRUIT BUD FORMATION. 



By B. S. Pickett. 



The subject of fruit bud formation is so comprehensive that any investiga- 

 tion into the causes which bring; about the formation of fruit buds, or into 

 means by which these causes may be controlled or directed, leads one into a 

 field so vast thai it becomes immediately apparent that the subject must be 

 studied phase by phase. Among the factors that underlie the formation of 

 fruit buds are climatic conditions, varietal forms and adaptations, supply 

 of plant food, supply of moisture, age or maturity of the plant, and its health or 

 vitality as affected by natural agencies such as attacks by insect pests, or 

 fungous diseases, or by artificial practices such as pruning, training, thinning, 

 and spraying. Investigations on fruit bud formation by the Department of 

 Horticulture at the New Hampshire Agricultural Experiment Station have, 

 therefore, been limited to such experiments as the material, means, and 

 time of the department required. They arc, however, designed to give 

 results of permanent value from a scientific standpoint as well as to furnish 

 data of pract Leal value to the fruit growers of the state. 



In accordance with the plan of limiting the field of investigation to the 

 means at the disposal of the department, it was decided to experiment only 

 with the most important fruit grown in the state, the apple, and further to 

 confine the work to the variety most largely grown, the Baldwin. The 

 factors chosen as fust in line for investigation include a comparative study of 

 certain methods of cultivation, fertilization and cover cropping. It was 

 further planned to experiment on the effects of both top and root pruning. 

 The material, however, proved unsuitable for this purpose, the plan for top- 

 pruning being abandoned at the outset of the experiment and the attempt at 

 special root-pruning being; abandoned at the close of the season of 1910. 



Method of Procedure. 



An orchard which, at the beginning of the experiment, consisted of 302 

 trees, was leased for a period of ten years. This orchard is located on the 

 farm of Mrs. 8. J. Woodman, and is two and one-half miles from the college. 

 With the exception of a few trees at the south end of the orchard all are Bald- 

 wins, and were about 25 years old at the beginning of the experiment. The 

 soil is sandy in character, remarkably uniform in physical characteristics from 

 end to end of the orchard, and almost perfectly level. It has an eastern 

 exposure and is protected on the west by a ridge in the adjoining field. The 

 orchard is divided into ten plots, separated by division rows. Another 

 plot, numbered eleven, crosses plots 7, 8, 9 and 10. Chart No. 1 illus- 

 trates the plan of the plots and the arrangement of trees in the orchard. Of 

 the original 302 trees a considerable number which, from one cause or another, 

 were considered unsuitable for the experiment, have been eliminated and do 

 not appear in the chart. 



The schedule of treatments of the various plots during 1908, 1909, and 1910 

 is as follows: 



