390 JOURNAL OF THE ROYAL HORTICULTURAL. SOCIETY. 



Apple, Bitter-Rot of, and Sources of Infection. By J. W. Roberts (U.S.A. 

 Bur. PI. Industry, Bull. 684, pp. 1-24 ; 5 figs.). — The bitter-rot in apples is 

 caused by the fungus Glomerella cingulata, and is widely distributed throughout 

 the States. The fungi can survive the winter in the host-plant, and these serve 

 as sources of infection for the following year's crop. These sources are as follows : 



(a) Mummy Apples : The fungus can live only one year in these apples. 



(b) Cankers on stem : The fungus may live for several years on an old canker. 



(c) Leaves : It is stated that the fungus may be found on the leaves. 



(d) Other host-plants besides the apples help to enable the fungus to survive 

 the winter months. 



The spores are scattered by rain, dew, insects, and possibly birds. Varieties 

 differ as to susceptibility to the disease. 



The removal of mummy apples and cankers, with spraying, is an efficient 

 control measure, and is recommended. — A. B. 



Apple, Black Spot. By W. Laidlaw and C. C. Brittlebank {Jour. Agr. 

 Vict. Aug. 1918, pp. 484). — -Three different brands of lime sulphur were used, 

 each giving equally good results, costing in material 3d. a tree. The best time 

 for the first spray is when more green than pink is seen ; the second spraying when 

 the centre flowers of cluster are fulty open. Result obtained from lime sulphur 

 was much better than from Bordeaux, 6-4-40 ; the foliage looked healthier and 

 remained longer on the trees ; the skin of the fruit had a better colour, and was 

 clearer and sappier-looking. It is desirable to have all the cultivation done before 

 spraying is commenced, as the resting spores developed in the fallen diseased 

 leaves of the previous season reach maturity at the time the apple and pear are 

 coming into bloom ; under favourable conditions these are blown in countless 

 numbers, and are carried by air currents up to the young leaves and fruits, where 

 they germinate and infect the crop. Cultivation should not be resumed till 

 all danger of infection is past. The results in clean, slightly spotted, and un- 

 marketable are in each case given. First spra}', 1 in 12, or 1 in 15 ; second spraying, 

 1 in 30 or 35. — C. H. H. 



Apple-Bud Selection : Apale Seedlings from Selected Trees. By C. S. Crandall 

 (U.S.A. Exp. Stn. Illinois, Bull. 211, June 1918; 43 figs.). — An attempt to dis- 

 cover whether there are differences in value for purposes of propagation between 

 large buds and small buds, between those produced on different parts of the tree, 

 and between those from different locations on the shoot. So far as growth of 

 trees is concerned, all buds from healthy shoots have been found to be of equal 

 value, and small scions have given as good results as stout ones. Fruiting results 

 are now being watched. — A. P. 



Apple Bug, The Green, in Nova Scotia. By W. H. Brittain (Dep. Agr. 

 N.S., Bull. 8, pp. 5-56 ; 11 plates). — This paper contains a very complete history 

 with control measures of Lygus communis var. novascotiensis, Knight, a serious 

 pest in apple, pear, and quince orchards. 



This insect is the forerunner of canker, and many trees are menaced by these 

 two pests. A very full description is given of the egg, nymphs in their several 

 stages, and imago. The most successful spray was nicotine sulphate, £ pint 

 to 100 gals, water, in two applications — (1) just before the blossoms open and 

 (2) after the blossoms have fallen. It must be applied in a driving, powerful 

 spray. 



Grease -banding in conjunction with spraying is urged to catch the dislodged 

 nymphs returning to the tree. — G. F. W. 



Apple Culture under Irrigation in Victoria. By J. Farrell (Jour. Agr. Vict. 

 June 1918, pp. 355-363, and August, pp. 454-462 ; illustrated). — C. H. H. 



Apple Maggot, The. By W. H. Brittain and C. A. Good (Dep. Agr. N.S., Bull. 

 9, Jan. 191 7, pp. 3-70 ; 7 plates). — This native species, Rhagoletis pomonella, 

 Walsh, is here reviewed with life history, natural enemies, control measures, and 

 a bibliography. It is a pest of small orchards, where spraying is seldom done. 



The eggs are laid beneath the skin of the fruit, and the larvae; on emerging, 

 tunnel the fruit in all directions. 



Picking up and destroying the fruit is an excellent remedy, but it is cheaper 

 to spray with lead arsenate, 2 lb. to 40 gals, water when the flies first appear, 

 which is about the middle of July, and again a fortnight later. — G. F. W. 



