iji 



THE SEARCH FOR BLIGHT-RESISTING CHESTNUT 



SPROUTS* 



Prof. J. Franklin Collins, Rhode Island 



The chestnut blight has now been with us for more than twenty 

 3'ears and has destroyed practically all the chestnut trees of the 

 northeastern part of the country. It has spread in all directions from 

 its original center in the immediate vicinity of New York City until it 

 has reached the limits of the native chestnut growth in the northeast 

 and north, and is steadih' apjjroaching its limits in the west and south. 

 The disease, a native of China and apparently imported into this coun- 

 try on some Japanese or other oriental chestnut, found a more sus- 

 ceptible host in our native chestnut and so became a virulent parasite 

 on this new liost. It was not until lOOi that general attention was 

 attracted to the disease. By tliat time it had obtained a strong foot- 

 hold on tlie chestnuts of southeastern New York (particularly the 

 western end of Long Island), in southwestern Connecticut, and in 

 northern New Jersey. 



All of you are more or less familiar with the efforts made in Penn- 

 sylvania, New York, and elsewhere in the northeast, in co-operation 

 witli the federal government, to control the disease. These efforts are 

 now an old story to most of you and there is no need of repeating it 

 at this time. 



Early in the fight against the blight the attention of many of us 

 was directed to locating possible immune or resistant species, varieties, 

 or individuals. The search for resistant native individuals and the ac- 

 companying experiments in crossing and grafting various species and 

 varieties has been kept up ever since. Foreign explorers have con- 

 stantly been on the lookout, with more or less success, for chestnuts in 

 other countries that might be resistant to the blight. It has long been 

 known that most forms of the Japanese chestnut (C. crenata) were in 

 genera] highly resistant to the blight. Later it was found that the 

 more recently introduced Chinese chestnut (C. mollissima) was also 



*N,ote--'-Blig'bt-resisting" as used in this paper should be interpreted 

 as a slower death of the host than in former years, whether or not the 

 result of increased resistance to the parasite on the part of the host, or 

 to decreased virulence of the parasite, or to both factors combined. 



