456 EXPERIMENT STATION RECORD. [Vol. 35 



5g), — Condensed notes are given on selected articles on animal pests and plant 

 diseases of the sugar beet in 1914 in Germany and Austria-Hungary. 



Dying of young fruit trees, A. H. Cockayne (Jour. Agr. [New ZecU.], 11 

 (1915), No. 6, pp. 504-506). — A serious disease already known to affect several 

 varieties of apples, also other fruits, has recently caused heavy loss. It is 

 characterized outwardly by a wilt of buds or young leaves in early spring and 

 inwardly by a browning of the inner bark and cambium. This browning appar- 

 ently always extends downward with considerable rapidity, being soon followed 

 in typical cases by a souring of the sap and sooner or later by the death of 

 the tree. 



Recent work has shown the trouble to be due to a fungus, though such pre- 

 disposing factors as unfavorable soil and climatic conditions may favor infec- 

 tion. The mycelium is found in the bark, cambium, and medullary rays and 

 vessels, blocking the water-conducting system. The fungal fructifications found 

 exteriorly have not yet been definitely connected with the internal mycelium. 

 The disease is said to resemble somewhat that caused by Valsa prunastri in 

 Europe, though certain specimens have shown fruiting bodies of the coral spot 

 fungus (Nectria cinnabarina) . The organism is thought to be a wound parasite. 

 Removal of all affected parts or trees Is recommended. Regrafting may, it is 

 thought, be practiced with safety. 



Some points on the general care of apple orchards, G. P. Stewabt (Proc. 

 State Hort. Assoc. Penn., 55 {WW, pp. 89-95, pi. i ) .—Discussing measures 

 designed to secure early bearing, control of aphids and red bugs, and immu- 

 nity to Stippen (or fruit-pit disease), the author submits provisional lists of 

 apple varieties regarded as susceptible in various degrees or as free from the 

 last-named trouble, which is thought to be physiological in its character. 



Spot diseases of the apple causing much general confusion, C. Beooks and 

 D. F. FisHEB (Better Fruit, 10 (1916), No. 8, pp. 13-15, fig. 1).— The authors, 

 presenting to the Washington State Horticultural Association a progress re- 

 port on studies designed to lessen the prevailing confusion regarding the 

 nature, appearance, causation, and control of the various apple spot dis- 

 eases, and discussing the origin and applicability of the names used therefor, 

 state that the names to which preference should be given or to which usage 

 is too firmly attached to be readily changed, are bitter pit, fungus fruit spot, 

 Jonathan spot, corky pit (or drought spotting), and stigmonose. 



On bitter pit and the sensitivity of apples to poison, II, A. J. Ewakt 

 (Proc. Roy. Soc. Victoria, n. ser., 26 (1913), No. 1, pp. 12-44, pls. S).— Having 

 employed in further investigations the methods described in a previous paper 

 (E. S. R., 27, p. 749), the author claims to have shown that it is possible, by 

 applying poison during the starch stage of development of an apple, to pro- 

 duce artificially every symptom of bitter pit. It is stated that the apples found 

 to be most resistant to poison are also most resistant to bitter pit. Low tem- 

 peratures increase resistance to poison as well as to bitter pit. The poisoning 

 theory is claimed to be in accordance with all that is known with regard 

 to the sensitivity of the pulp cells toward poisons, to their diminishing resist- 

 ance with increasing age, and to the changes which take place in the cell, 

 the increased percentage of ash in bitter tissue also pointing in the same 

 direction. It is claimed that it is possible to poison the pulp cells of apples 

 by traces of poison so minute as to be incapable of detection by delicate 

 chemical analysis. The brovTuing of apple pulp is said to be due to the 

 oxidation of tannic acid. 



Other chemical and biological considerations are discussed, and a critical 

 examination is made of the views set forth in the reports of McAlpine (E. S. 

 B., 32, p. 751; 33, p. 852). 



