58 



PLANT INTRODUCTION AS APPLIED TO BLIGHT- 

 RESISTANT CHESTNUTS AND RELATED CROPS 



By B. T. Galloway 



Office of I-'oreign Plant Introduction, U. S. Department of Ao-ricnlture 



At the suggestion of Secretary Colby, I desire to present .at tliis 

 time a brief progress report on the work conducted by tlie United 

 States Department of Agriculture in its search tliroughoiit tlie worhl 

 for blight-resistant chestnuts and related crops. 



Explorations in foreign countries, "for eliestnuts and other tree 

 crops, liave been under way for many years but the work has been 

 intensified during tlie past fifteen years, since it became evident that 

 our native chestnut was likely to be eventually wiped out by the blight 

 fungus. One of the first important results of this work was the dis- 

 covery of the original borne of chestnut blight by an agricultural ex- 

 plorer of the Bureau of Plant Industry, who was engaged in work in 

 China. This discovery was made in 191 ."5. At the same time, and in 

 the same general region where blight wis discovered, large areas of 

 chestnuts were located, which proved to be a resistant species known 

 botanically as Castanea mollissima, and now conunonly referred to as 

 the Chinese hairy chestnut. A large number of introductions of the 

 nuts of tliis species have been made from China. The species has a 

 wide range in Cliina and varies as to si/c of tree, quality and size of 

 nuts and possibly also ability to resist blight. Evidence has repeatedly 

 come to light in China that blight lias existed there for a long time 

 and that numbers of ways have been devised for combating it. Un- 

 doubtedly, through long natural selection, the resistant strains we are 

 now testing have been developed. In our exploration work we have 

 covered practically the whole of China. In 1921-1922 a special ex- 

 pedition was sent into extreme western China. The result of this 

 work was the discovery of some new types of Castaneas and a large 

 number of Castanopsis^ a related genus which we shall speak of later. 



In the earlier introduction work seeds were brought in and seed- 

 lings grown at one or more of our Plant Introduction Gardens. The 

 first seedlings were distributed somewhat ])romiscuously and in small 

 lots. The losses were necessnrilv heavy, but enough trees were es- 



