ANNUAL REPORT, 1937 87 



position of the various treatments was essentialh- the same as in 1936. For this 

 reason, no change is necessary in the statements made in 1936 concerning the 

 various treatments. 



The study to determine the cause and the cure for chlorosis of cultivated blue- 

 berries, which was started in 1935, was continued in 1937. A progress report 

 covering this work will appear in the Proceedings of the American Society for 

 Horticultural Science for 1937. 



Blueberry Culture. (J. S. Bailey.) The study of the self-pollination of the 

 cultivated blueberry was continued in 1937. A report covering the results of this 

 work from 1935 to 1937 will appear in the Proceedings of the American Society 

 for Horticultural Science for 1937. Experiments were started to determine the 

 effect of Gamma (Indole-3)-n-butyric acid on the rooting of blueberry cuttings. 

 This material was tried on dormant cuttings at concentrations of five, ten, and 

 twenty milligrams per hundred cubic centimeters of water for twelve, tw^enty- 

 four, and forty-eight hours at each concentration. Dormant cuttings showed 

 little or no response when treated for twelve or twentx'-four hours at any of the 

 three concentrations. Treated for forty-eight hours, all three concentrations 

 appeared to be toxic. Green wood cuttings taken in July just as secondary- growth 

 started were treated for twelve and twenty-four hours with solutions and con- 

 centrations of five and ten milligrams per hundred cubic centimeters of water. 

 There appeared to be a slight stimulation of rooting in those cuttings treated for 

 twenty-four hours at a concentration of ten milligrams per hundred cubic centi- 

 meters. 



For several years blueberry Plot A has been handled under a mulch system, 

 using sawdust and shavings for the mulch. There has never been any indication 

 of mice working in this mulch. In the summer of 1937, Blueberry Plot B was 

 mulched with a heavy coating of waste hay. In October there was ample evidence 

 of a heavy infestation of mice, although this plot is surrounded by plowed land 

 on which a cover crop of buckwheat was grown. This difference in the preference 

 of mice for the two types of mulch may be an important consideration in the 

 mulching of blueberry fields in sections where mice are prevalent. 



A row of Jersey plants in Plot C bore their first crop this year. This variety- 

 looks very promising. The berries were large, very attractive, firm, and of ex- 

 cellent flavor when well ripened This variety seems to tolerate a drier soil than 

 most other varieties. The variety Pioneer was rather disappointing in its per- 

 formance in 1937 because the berries tended to drop off considerably in size at 

 the end of the season. The variety Cabot apparently needs picking oftener than 

 other varieties since it has much more of a tendency to drop as soon as ripe. 



Premature Dropping of the Mcintosh Apple. (L. Southwick.) Work on this 

 project was continued in the light of certain conclusions derived from last year's 

 data. It was found that a study of the total population (entire crop) of a tree 

 gave more significant results than a study of any one particular section of that 

 tree. This possibly is explained by variations between different branches. 



This past summer variable fertilizer treatments including direct limb injec- 

 tions were initiated. Also a precise dropping record of numbered app'es on three 

 Mcintosh trees was kept. Percentages of dropped fruit will be computed, as in 

 years past, for each Mcintosh tree in the Station Orchards. The year 1937 will 

 go down as one with heavy drop. 



The most significant finding to date is the correlation of time of dropping with 

 fruit seed number. As a general rule the early drops contain fewer fully developed 

 seeds than those apples that hold on. This seems to hold true for short time dura- 

 tions, even a few days. There is also inconclusive evidence pointing to the prob- 



