NOTES AND ABSTRACTS, 



Potash Manures {Jour. Bd. Agr. vol. xxi. No. 6, pp. 562-563).— 

 As this country's supply of artificial potash manures comes almost 

 entirely from Germany, it is important that new sources of potash 

 manures should be sought. The natural supplies in all sorts of 

 vegetable refuse should be carefully utilized. — A . 5. 



Potash, Why waste ? Anon. {Perfumery Record, Oct. 1914, 

 p. 374). — Draws attention to the high percentage of potash in sea- 

 weeds, hedge trimmings, furze, and common weeds, such as groundsel, 

 and recommends the utilization of their ashes for those purposes for 

 which potash is required. — F. J. C. 



Potato Spraying. By the Duke of Bedford, K.G., F.R.S.. and 

 Spencer U. Pickering, M.A., F.R.S. {Wohurn, 14th Rep., 1914, pp. 1-32). 

 — ^The initial object of the experiments detailed was to ascertain the 

 proportion of Woburn Bordeaux paste which was equivalent in 

 fungicidal action to ordinary Bordeaux mixture. The former is simpler 

 to prepare, and by its use a much smaller quantity of copper is required 

 to produce a given result. The conclusion is arrived at that for the 

 treatment of potatos 15 to 16 lb. of the paste (containing copper 

 equivalent of 10 per cent, of its weight of copper sulphate) to 100 

 gallons of water are equivalent to 8 lb. of copper sulphate in the 

 form of the mixture, though it does not necessarily follow that this 

 same equivalent would hold good for other fungus diseases, and 

 where scorching of the foHage is to be feared it would be safer to adhere 

 to half this proportion of paste. It is estimated that, with a fairly 

 good crop and in a year when disease is rife, one spraying with a 

 fungicide of the full strength mentioned should result in an increase 

 of 10 to 30 per cent, of sound tubers. 



The decomposition of the paste in some cases has been a drawback 

 to its general adoption, but a method has been discovered of arresting 

 this, and it is understood that samples are now put to the test of 

 some hours' boihng before being put on the market.—^. P. 



Prickly Pears of Australia (continued). By J. H. Maiden 

 {Agr. Gaz. N.S.W. vol. xxv. pp. 137, 138, 519, 520 ; 4 figs. ; 2 col. 

 pL). — The Golden-bristled Prickly Pear {Opuntia microdasys), a native 

 of Mexico, is grown for ornamental purposes. It is a low- growing shrub 

 with oval joints and yellow fragile bristles. 



The Queensland Prickly Pear, know^n in Queensland as Red Mexican, 

 has large joints and powerful spines. The fruit is edible. As it is a 

 robust grower it is a pest in some districts. — S. E. W. 



Prunus, Cylindrosporium Disease of. By B. B. Higgins 

 {Amer. Journ. of Bot. vol. i. No. 4, pp. 145-173 ; 4 plates). — The author 

 gives an elaborate account of the hfe-history and physiology of the 

 fungus Cylindrosporium, Vv^hich causes a disease of plums and cherries, 

 and has for many years attracted the attention of horticulturists and 

 plant pathologists in Europe and America. In certain species of Primus 



