406 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Apple-grain Aphis. By A, C. Baker and W. F. Turner {Jour. Agr. Res., 
i8, Dec. 15, 1919, pp. 311-334). — An outline of the life-history of the apple aphis 
Rhopalosiphum prunifoliae Fitch is given. Eggs are laid in depressions on small 
branches ; in mild attacks on large trees only in the lower part. The eggs 
hatch in early spring and the usual sequence of generations is followed. The 
aphides migrate in summer, but the alternate host is not stated. This aphis 
has been confused with Aphis avenae {R. padi L.). — G. F. W. 
Apple Leaf Jassid. By W. W. Froggatt {Agr. Gaz. N.S.W. vol. xxix. 
pp. 568-571 i I plate), — The Apple-leaf Jassid or Frog Hopper {Empoasca mali) 
damages the fruit and foliage of the apple. Fallen leaves and weeds should be 
dug into the soil, and in early summer the trees should be sprayed with kerosene 
emulsion or tobacco-soap wash, A new species, Empoasca australis, is' in colour 
deep yellow, in which respect it differs from E. mali. It does not cause the leaves 
to curl up at the sides, — S. E. W. 
Apple, Powdery Mildew of the. By D. F. Fisher {U.S.A. Bur. PI. Ind., Bull. 
1 120, pp. 1-14 ; 8 figs.). — This disease is caused by Podosphaera leucotricha 
(E. & E.) Salm., which makes a felt-like growth on stem, leaves, blossoms, and 
fruit. It is an external parasite and penetrates the host plant by " suckers," 
which absorb sap from the cells of the apple. It is more frequently met with 
in dry climates and may cause much damage to nursery stock. The fungus is 
found upon the pear, quince, hawthorn, cherry, plum, and other fruits as well as 
the apple. The varieties least susceptible are ' White Pearmain ' and ' Winesap.* 
Spraying three or four times with lime sulphur i in 50 is recommended as a means 
of control. — A. B. 
Apple, Powdery Mildew. By E. Breakwell, W. J, Allen, and W, Le G. 
BTeieton {Agr. Gaz. N .S.W. vol. xxix. pp. 408-412). — When apples are affected 
by powdery mildew, all diseased wood and mildewed terminals must be cut 
out and burnt in autumn. When the blossom buds show pink, spray with 
sulphide of iron, later spray with sulphide of iron and lead arsenate. Three 
weeks later repeat this treatment, and once more if necessary. 
The iron sulphide is prepared by adding 2| gallons of commercial 
lime-sulphur to 12 pounds of iron sulphate dissolved in 32 gallons of water. 
Allow the black precipitate to settle, syphon off the clear liquid, and wash the 
precipitate three times by decantation. Finally add sufficient water to make 
the total volume 50 gallons. 
Mix a portion of this stock mixture with nicotine or lead arsenate as required, 
and add water to bring the bulk to ten times the original volume. — S. E. W. 
Apples, Cost of Producing in Yakima Valley, Washington. By G. H. Miller 
and S. M. Thomson {U.S.A. Dep. Agr., Bull. 614, April 1918 ; 6 plates, 14 figs.). — 
A study of apple-orcharding in 1915. The average annual acre cost on the 120 
farms dealt with was found to be $345.68, which, allowing for an annual yield 
of 432 boxes to the acre, works out at about $0.80 per box. The greatest item 
of fixed cost was the interest on the money invested, which accounted for nearly 
a quarter of the total net annual cost. — A . P. 
Apples, Storage Diseases of . By Chas. Brookes, J. S. Cooley, and D. F, Fisher 
{U.S.A. Bur. PI. Ind., Bull. 1160, pp. 1-25 ; 26 figs.)- — The diseases of storage 
apples depend upon conditions which influence the development of parasitic 
fungi, and also upon abnormal physiological conditions in the fruit itself ; and 
these are largely due to bad storage conditions. Scald and various apple rots 
are often produced when temperature of storage is high, while deficient ventila- 
tion is also a contributory factor. Each variety of apple, however, has its 
storage limitations, and these vary from year to year. — A. B. 
Arisaema Fargesil Bucket. By C. H. Wright {Bot. Mag. t. 8861, Sept. 1920), 
— Spathe purple with paler lines, yellow or greenish. Native of Szechwan and 
thriving under greenhouse treatment. — F. J. C. 
Atraphaxis Billardleri Jaub, et Spach. By O, Stapf {Bot. Mag. t. 8820 ; 
Dec. 1919)- — A mountain shrub of Greece, Crete, Asia Minor, and Syria, remark- 
able for its bright perianth segments, which enlarge after flowering. It is hardy 
in the neighbourhood of London, where it forms a dwarf semi -prostrate shrub. 
F. J. C. 
Avocado in Guatemala. By W, Popenoe {U.S.A. Dep. Agr., Bull. 743; 
23 plates). — Thirty-six varieties of avocado grown in Guatemala are described. 
5. E. W. 
