84 DErAKTMENTAL REPORTS. 



During the year several lines of viticultural investigation have been 

 inaugurated in addition to those previously begun. A comprehensive 

 descriptive index of varieties of Yinifera graj^es, with their full syno- 

 nyms, has been commenced and will be added to as rapidly as the other 

 duties of the expert permit. A beginning has been made in forming 

 a viticultural herbarium, and nearly 200 varieties of grapes have been 

 received and described. 



An experiment was made early in 1901 to determine the effect of the 

 hot- water dip sometimes used to rid grape cuttings of Phylloxera infes- 

 tation. In this experiment grape cuttings were treated by dipping in 

 water at different temperatures from 122° F. to 140° F. for varying 

 lengths of time. It was found that no injury resulted from a tempera- 

 ture of 122° F. for five minutes. At the same temperature a dip of ten 

 minutes resulted in decided injury, while at 140° F, for five minutes 

 the cuttings were practicallj^ all killed. The effect of the dip was 

 accurately determined by i)lanting equal numbers of cuttings, both in 

 the open ground and in the greenhouse and making observations upon 

 them as the season progressed. 



An extensive exj^eriment in bench and field grafting of Vinifera 

 grapes of different types and varieties on different resistant stocks has 

 been begun. This experiment is made with a view to detrermining as 

 promptly as possible the relative congeniality of different Vinifera 

 varieties to different resistant stocks, as well as the relative rooting 

 characteristics and adaptability to different soils of the latter. Several 

 methods of grafting are under test in a comparative way in connection 

 with the same experiment. This work is for the present conducted at 

 Washington, but will have distinct bearing on future developments in 

 the work in the South Atlantic States and on the Pacific coast. 



The experimental vineyards established in 1899 in North Carolina 

 and Florida are now yielding very interesting and valuable results. 

 In Florida the distinct superiority of stocks of the Rupestris tj^jje over 

 those of the Riparia type on the sandy soils that are representative of 

 a large portion of the State has been demonstrated. A number of 

 Vinifera varieties in the collection at Earleton are considered exceed- 

 ingly promising and worthy of commercial planting in a small way on 

 suitable stocks in favorable locations in that State. 



In North Carolina the behavior of the vines is less encouraging. 

 This is probablj^ partially due to the difficulty in securing skilled labor 

 to care for the experimental vineyard, but appears to be chiefly due 

 to the less favorable climatic conditions in that region during the sea- 

 son of 1901. Notwithstanding the unfavorable conditions which greatly 

 lessened the output of native grapes in that section, a number of Vin- 

 ifera varieties on resistant stocks have made good growth and have 

 borne good crops for two years past, indicating that there is still a 

 possibility of their successful culture in that section. Some of them 

 have produced better crops and better fruit than either the Niagara or 

 Delaware, the leading commercial varieties of the region, and have 

 proved less subject to black rot than the Niagara. 



In connection with the effort to develop choice table grapes in the 

 South a considerable number of cuttings and vines of different varie- 

 ties have been distributed to individuals and experiment stations. 

 An investigation of the methods of manufacture of unfermented 

 grape juice, its use, its effects on the human system, and its imi)or- 

 tance as a commercial product has been instituted. Rapid progress 

 has recently been made in this line of manufacture, and unfermented 

 grape juice is now an important article of commerce. Some changes 



