1G6 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



to the usual manures acts beneficially. Chalk must on no account be 

 used with a sandy soil. — S. E. W. 



Potato "Seed" Stock, Proper Growing- and Handling- of. 



By C. D. Woods and W. J. Morse (U.S.A. Exp. Stn., Maine, July 

 1911). The export of northern-grown potatos for seed in Southern 

 States is on the increase, and this bulletin deals with several points 

 that have arisen in connexion with the trade. The need for securing a 

 uniform stock true to name is insisted upon, and it is advised that 

 the produce of only those plants which produce five to seven good and 

 uniform tubers should be saved for seed purposes, and from these 

 the general crop of seed potatos should be grown. The growing of 

 test plots by the seed producers is also recommended. The seed, it 

 is said, should be stored in cool houses and sent south only in cool 

 weather. Diseases said to be carried by seed tubers are, that caused 

 by Phytophthora infestans, dry-rot {Fusarium), blackleg (Bacteriosis), 

 and scab. The symptoms of these diseases are dealt with, and means 

 of selecting out diseased tubers described. It is recommended that 

 potato sets should be stored in the dark (many British growers recom- 

 mend that they should be exposed to light during storage). Care 

 should also be exercised that bruising is avoided. — F. J. C. 



Potato-spraying" experiments in 1910. By F. C. Stewart, 

 G. T. French, and F. A. Sirrine {U.S.A. Exp. Sta., Bull. 338; May 

 1911; 1 plate, xxv. tables). — A general summary of the experiments 

 of the year indicates that those who spray most obtain the largest net 

 profit. There is little danger of over-doing it. At Geneva six spray- 

 ings increased the yield 63 bushels to the acre, and three sprayings 

 increased it 22 bushels. Flea beetles, early blight, late blight, and rot 

 were all factors in the experiment. — V. G. J. 



Potatos, Mutations in (Rev. Hort. p. 415; Sept. 16, 1911).— Dr. 



Edouard Heckel, Director of the Colonial Institute of Marseilles, 

 reports on the mutations of Solanum Maglia under culture. The 

 tubers obtained, about 4 lb. from each plant, were ripe at the beginning 

 of August ; they were all violet, like those of Commersonii ' Violet ' of 

 M. Labergerie, and of the same form. Their resistance to crypto- 

 gamic disease was altogether remarkable. Dr. Heckel also stated 

 that M. Verne, Professor of the University of Grenoble, had, at his 

 instigation, traversed much of South America to collect the wild 

 potatos of the wild lands of the coastal regions and high up the Andes 

 to a height of 3000 to 4000 metres. Visiting the Argentine, Chile, 

 Brazil, Peru, and Bolivia, he has obtained a large number of tubers 

 of numerous wild varieties, which will be subjected to Dr. Heckel's 

 mode of studying bud mutation induced by plentiful applications of 

 farm manure. — C. T. D. 



Prickly Pears. By J. H. Maiden (Agr. Gaz. N.S.W. vol. xxii. 

 pt. viii. pp. 696-7; 1 coloured plate). — Opuntia imhricata has escaped 

 from cultivation and threatens to be a serious pest. — S. E. W. 



