NOTES AND ABSTRACTS. 



391 



Apple, Powdery Mildew of, and its Control. By D. F. Fisher (U.S.A. Dep. 

 Agr., Bur. PL Ind., Bull. 712, Oct. 1918, pp. 1-28 ; 3 plates). — The mildew is 

 generally prevalent in the arid regions of the Pacific North West, where some- 

 times more than 50 per cent, of the crops are attacked. The causal organism 

 (Podosphaera leucotricha (E. and E.) Salm.) winters in dormant buds as mycelium, 

 is spread by wind-carried conidia, and can readily germinate upon leaves and 

 buds and fruit. The disease is controlled by sulphur sprays during the growing 

 season. Bordeaux mixture is less effective than sulphur sprays. It is suggested 

 that three applications should be applied during the season. — A. B. 



Apple Scald. By Chas. Brooks, J. S. Cooley, and D. F. Fisher (U.S.A. Jour- 

 Agr. Res. xvi. No. 8, Feb. 1919 ; pp. 195-217). — It is found that well-matured 

 apples are much less susceptible to scald than immature ones, and that apples 

 from heavily irrigated trees scald worse than those from trees receiving more 

 moderate irrigation. The scalding does not take place at 25°-30° C. Scald is 

 considerably reduced by decreasing the humidity, while 1 per cent, to 6 per 

 cent, carbon dioxide tends to prevent it. Apples susceptible to scald have-been 

 made immune by storing for a few days in carbon dioxide gas. A constant air 

 movement of £ to £ mile an hour practically prevents apple scald. Apples 

 packed in boxes or ventilated barrels scald much less than those in tight barrels. 

 It is supposed that apple scald is due to volatile or gaseous substances other 

 than carbon dioxide that are produced in the metabolism of the apple, and 

 these substances can be carried away by air currents or removed by various 

 absorbents. — A. B. 



Apples, Cost of Producing, in Western Colorado. By S. M. Thomson and G. 

 H. Miller (U.S.A. Dep. Agr., Bull. 500, March 1917; 10 figs.). — A detailed study 

 made in 191 4-1 5 on 125 fruit farms. Similar studies have been made in Flood 

 River Valley (Bull. 518), and Payette Valley, Idaho (Bull. 636). — A. P. 



Apples, Seed Production in. By Charles S. Crandall (U.S. A . Exp. Stn., Illinois' 

 Bull. 203, August 1917, 8 figs.). — Over 30,000 fruits were examined, and it was 

 found that seed production in large fruits exceeded that in small, and was nearly 

 twice that recorded for crab fruits. Control of pollination showed no marked 

 influence on the number of seeds developed. A small test was made of fruits 

 having no developed seeds (parthenocarpic), and they were found to exceed in 

 weight an equal number of fruits selected at random which were highly pro- 

 ductive of seeds. Certain varieties exhibited a strong tendency to multipli- 

 cation of seeds, large Shockley fruits averaging fifteen seeds each as against the 

 full complement of ten in a normal fruit. — A . P. 



Araliaceae. By R. Viguier (Rev. Hort. vol. xci. pp. 228, 229, 250-252). — 

 With the exception of the Ivies the Araliaceae are exotic. They are cultivated 

 for their foliage, as their flowers are insignificant. They may be classified 

 according to the shape of their leaves : (1) simple leaves, (2) palmate leaves, 

 (3) pinnate leaves. — S. E. W. 



Arsenate of Lime. By G. E. Sanders (Dep. Agr. Canada, Crop Protection 

 Leaflet 10). — Arsenate of lime or calcium arsenate is recommended on grounds 

 of economy in cost for spraying apple, pear, and potato, and to supersede lead 

 arsenate, but it is not safe on tender foliage trees as cherry, peach, or plum. 



If used by itself, a yellowing and often burning of the foliage results, but in 

 conjunction with the following the results are promising. 



1. Bordeaux mixture — 1 lb. of calcium arsenate to 40 gals. Bordeaux 

 mixture. 



2. Lime-sulphur — f lb. of calcium arsenate to 40 gals, lime sulphur, with 5 lb. 

 of hydrated lime added. 



3. Sulphide washes — £ lb. of calcium arsenate to 40 gals, sulphide wash, with 

 10 lb. of hydrated lime added. — G. F. W. 



Asparagus. By H. C. Thompson (U.S.A. Dep. Agr., Farm. Bull. 829, pp. 1-20 ; 

 10 figs.). — In preparing the soil for asparagus, plough in 20-40 tons of farmyard 

 manure an acre. Every year, at the end of the cutting season, apply 1,000- 

 1,500 lb. an acre of a fertilizer containing 2-4 per cent, of nitrogen, 6-8 per cent, 

 of phosphoric acid, and 6-8 per cent, of potash, preferably in the form of 

 potassium chloride or kainit. 



• Reading Giant,' 4 Argenteuil,' and ' Palmetto ' are rust-resisting varieties. 



For canning, blanch the shoots by immersion in boiling water, then plunge 

 into cold water; arrange in cans or jars, tips up, cover with brine containing 



