1917] DISEASES OF PLANTS. 151 



it Is thought may prove to be the incipient stages of the circular white patch 

 condition. 



Manual of fruit diseases, L. R. Hesler and H. H. Whetzel {Netv York: Tlie 

 Macmillan Co., 1917, pp. XX+462, figs. 126).— The authors give popular de- 

 scriptions, together with suggestions for control, of bacterial and fungus dis- 

 eases, as well as those of unknown causation, of the apple, apricot, blackberry, 

 cherry, cranberry, currant, gooseberry, grape, peach, pear, plum, quince, rasp- 

 berry, and strawberry. The various diseases are treated in the order of their 

 usual economic importance. A chapter is devoted to the importance of the 

 preparation of some of the more common copper and sulphur fungicides. The 

 information given is designed for fruit growers and embraces the results of 

 recent investigations. 



Bitter pit, D. McAxpine {Fruit World Austral., 17 (1916). No. 1, pp. 2, 3, 5. 

 7, figs. 2). — Tlie author discusses bitter pit control as regards fruit on the tree, 

 in storage, and in transit, also the influence of resistant stocks. 



The trouble is worse on main branches and spurs thereof than on laterals 

 and their spurs, on pruned than on unpruned laterals, on trees bearing a few 

 large fruits than on those bearing many small ones, on trees with large than on 

 those with small bearing surface, on rank than on less profuse growths, and 

 on trees having very abundant or irregular water supply and faulty transpira- 

 tion. Drainage, cultivation, manuring, and in general maintenance of good 

 conditions are considered important means of prevention and regulation. It has 

 been found that in apples kept at 30 to 32° F. in storage or transit the develop- 

 ment of bitter pit and ripening are practically arrested. Breeding of resistant 

 varieties is regarded as a possibility. 



The Illinois canker, or the blister canker of the apple tree, D. E. Lewis 

 {Trans. Kans. State Hort. Soc, 33 (1914-15). pp. i7'5-i78).— Observations are 

 sunnnarized on blister canker (Nummulario discreta), said to have been present 

 In Kansas for more than 15 years and very destructive for several years dur- 

 ing some of the latter part of that period (owing to the weakening effect of 

 drought). The author outlines tlie development and the effects of the attack, 

 and the control measures favored, which consist in selection of resistant varie- 

 ties (some of which are named), and in aeration and general sanitation. 



Notes on an apparent relation between aphids and fire blig'ht (Bacillus 

 amylovorus), J. H. Merrill ('rrans. Kans. State Hort. Soc, 33 (1914-15), p. 

 71). — Observations carried on since 1913 in Doniphan County by the department 

 of entomology of the Kansas Experiment Station are said to have shown that 

 where aphids are kept down by spraying with black leaf 40, tlie percentage of 

 attack by fire blight (B. amylovorus) is greatly diminished and in some cases 

 is practically zero. Comparatively few aphids were found in orchards which 

 had received a thorough dormant spraying with lime-sulphur. 



Ripe rot of stone fruits, A. B. Mansfield (Jour. Agr. [New Zeal.], 12 (1916), 

 No. 3, pp. 214-216, figs. 2). — It is stated that in the Auckland districts the loss 

 In stone fruits due to ripe rot (Monilia fructigena) has recently been consider- 

 able. The term ripe rot is preferred to that of brown rot, the latter being 

 deemed more appropriate to a similar disease of apples and similar fruits. 



Grape downy mildew in Algarve, P. P. M. Judice (Bol. Assoc. Cent. Agr. 

 Portnguesa, 18 (1916), N,os. 3, pp. 81-90; 4, pp. 126-137).— This is an account 

 of observations carried out in the Province of Algarve during a number of years 

 on the intensity of mildew attack in connection with meteorological conditions. 



It is stated that the attacks in this region have usually been of comparatively 

 slight intensity, varying from year to year and with the locality in the same 

 year. Some localities never have suffered from mildew attack, so that while 

 three or more treatments are considered as technically advisable, these are not 



