EEPORT OF THE SECRETARY. 65 



In the export and manufacturing districts special attention has been 

 given to the problem of securing an adequate supply of humus in the 

 tobacco soils, which undoubtedly constitutes the key to improving the 

 yield as well as the quality of the crop in nearly all these districts. 

 This problem is of the greatest importance to the grower because of 

 the fact that most legumes are likely to exert an injurious effect on 

 the quality of the tobacco when preceding this crop in rotation. 



An important feature of the tobacco work of the year has been a 

 careful study of the effects of environment on the habits of growth of 

 the plant and on the quality of the cured product, the principal ob- 

 ject of this work being to afford a proper guide to the development 

 of improved varieties by systematic breeding. The extensive studies 

 relating to the plant-food requirements of the tobacco crop which 

 have now been in progress for several years have been continued along 

 the same lines. 



INVESTIGATIONS IN POMOLOGY. 



The work of identifying fruits has increased to a very large extent 

 during the year, identifications being made of fruits from every sec- 

 tion of the country. 



A revision of the catalogue of the American Pomological Society 

 is now under way. The value of this catalogue to the fruit interests 

 of the country can hardly be overrated, since it has for years been 

 the standard conservative authority upon the value of varieties for 

 the whole country. The forthcoming revision will make the cata- 

 logue more comprehensive and exhaustive than ever. 



Investigations looking to the simplification of fruit nomenclature 

 have been pushed vigorously, resulting in the accumulation of sev- 

 eral thousand card references to the history, origin, distribution, 

 synonymy, description, classification, etc., of the cultivated fruits of 

 the country. 



The collection of fruit varieties at the Arlington Farm has been 

 materially increased during the year. The collection is furnishing 

 admirable opportunities for obtaining information at first hand con- 

 cerning the relative merit of varieties. 



Special attention has been devoted to the Persian walnut. Effort 

 is now being made to introduce foreign varieties, to the end that a 

 thorough test may be made of those that give promise of meeting the 

 demands for an extension of the area of cultivation. 



FRUIT- MARKETING, TRANSPORTATION, AND STORAGE INVESTIGATIONS. 



Investigations on the marketing, transportation, and storage of 

 fruit have consisted mainly of a study of the relation of handling 

 methods to decay and deterioration in oranges and pomelos in 

 Florida; table grapes, oranges, lemons, and apples in California; 



23165"— AGE 1911 5 



