BUREAU OF PLANT INDUSTRY. 453 



propagating. Special attention is being given to the pollination of 

 the Muscadine grapes. While the vines are botanically monoecious, 

 two varieties have been found Avhich are dioecious and therefore self- 

 pollinating. This advance in INIuscadine grape work indicates the 

 possibility of estabUshing vineyards of self-pollinating vines and 

 thus greatly facilitating the improvement of the native varieties by 

 selection. 



Fruit improvement. — The investigation of the improvement of 

 citrus fruits through bud selection has been in progress during three 

 full seasons. The data obtained from careful observations on the 

 bearing of Washington Navel oranges and Marsh grapefruit, or 

 pomelos, continue to show very marked differences in the yields of 

 individual trees of the same age growing under the same conditions. 

 The large-yielding trees have produced maximum crops during the 

 three seasons, while the small bearers have consistently proved to be 

 shy in bearing properties throughout. This w^ork was extended to 

 the lemon durnig the past year, and consistent results with this fruit 

 are also being obtained. Close studies on the character of variations 

 in citrus fruits are being made. 



This work has received wide recognition from citrus growers, and 

 the department investigation is serving as a basis for the selection of 

 propagating material, both in the establishment of new plantations 

 and in rebudding operations. Citrus growers have followed the de- 

 partment work very closely, and many have made individual tree 

 studies; one large company, operating more than a thousand acres, 

 now determines the production of each tree in its groves. 



These investigations are being gradually extended to deciduous 

 fruits, two seasons' observations having been made on peaches in 

 Connecticut. Field studies of apples are in progress, and it is hoped 

 that systematic work along these lines with apples and other decidu- 

 ous fruits can be carried on during the coming fiscal year. 



Nut culture. — The work of acquiring information regarding the 

 adaptability of the principal species of nut trees grown in the States 

 east of the Kocky Mountains to special localities, the comparative 

 behavior of varieties, the details of orchard operations, and the study 

 of the nuts themselves, along the lines which have been in progress 

 during the preceding years, has been continued during the fiscal year 

 just closed. 



The principal new work inaugurated during the year was that 

 of obtaining exact bearing records of pecan orchards. Promises of 

 orchard yields proportionate to the returns from occasional single 

 trees have induced many persons to make investments in pecan grow- 

 ings during the past five years. The records already acquired have 

 established the fact that trees of the same age, variety, and apparent 

 environment may vary greatly for any single tree; hence, the danger 

 to capital invested on the strength of such computations is beyond 

 question. The obtaining of records from entire orchards is therefore 

 of very great importance to all prospective planters. 



Plans for future work. — It is planned to continue all lines of 

 investigations now under way and to take up such new problems as 

 may be possible, special attention being devoted to the ))rocuring of 

 data on orchards and individual trees, in order to bring about a 

 greater degree of uniformity within established varieties. 



