152 EXPERIMENT STATION RECORD. [Vol. 38 



terminal branches, the marked or amraoniated fruits, the bark excrescences, and 

 the multiple buds. The secondary symptoms are an exceptionally deep green 

 color of the foliage, a distorted growth of the immature angular terminal 

 branches, frenching of the foliage, and thick, coarse, and somewhat peach-leaf 

 shaped leaves. 



The definite cause of dieback is not known, although it is supposed to be 

 connected in some way with organic matter in the soil. Conditions known to be 

 favorable to dieback are the presence of excessive quantities of ammoniates, a 

 lack of drainage, hardpan too near the soil surface, excessive cultivation, and 

 irregular moisture conditions. 



The disease n»iy be controlled by correcting the above soil conditions, and 

 affected trees may be cured by the use of copper sulphate on the soil and be- 

 neath the bark of the trees and by spraying with Bordeaux mixture. 



Armillaria root rot on the English walnut, K. Peakcy {Arncr. Nut Jour., 

 6 (1917), No. 6, p. 85). — <jiving the results of experience with Armillaria root 

 rot attacking English walnuts of all ages and at all seasons locally, the author 

 states that where the dirt was dug away until the graft unions were exposed, 

 cylinders of heavy roofing paper placed around the bases of the trees, and the 

 soil filled in around them afterwards, no more trees were lost in that planting. 

 These cylinders have to be kept cleaned out each year of such dirt as may 

 fall into them during cultivation. Holes where dead trees have been dug 

 out must be left open to the sunshine for a time to kill any portions of the 

 fungus that may be exposed. 



A new disease of cultivated Pelargonium, A. Lingelsheim (Ztschr. Pflan- 

 zenkranlc, 26 {1916), No. 6-1, pp. 315-318, figs. 2).— A brief description and 

 discussion are given of a speckled appearance twice observed in young leaves 

 of Pelargonium. The phenomenon becomes more apparent in the older leaves. 

 The cause is thought to be defective development of some of the parenchymal 

 cells as regards size and chlorophyll content. The observed phenomena are 

 compared with some reported by other authors. 



Hybrids and other new chestnuts for blight districts, W. Van Fleet 

 (North. Nut Growers Asi^oc. Proc, 1 (1916), pp. 5//-5S).— It is stated that no 

 diminution in the virulence of the chestnut-bark disease is yet apparent, the 

 disease having spread within a little more than ten years from a point near 

 New York City into 13 States, practically reaching the eastern and northern 

 limits of chestnut growth and sparing no individual trees exposed to infection, 

 so that the American chestnut as a forest asset is likely soon to disappear. 



Chestnut trees are killed in a short time, though a duration of five to eight 

 years has been noted. The fungus probably does not, however, attack very 

 harmfully even closely allied forms. Certain Asiatic forms, as Castanea 

 crenata of Japan and eastern China and C. molissima of the interior are most 

 promising in this respect. C. sativa, the commercial chestnut of Europe, has a 

 resistance somewhat higher than that of C americana. C. pumila often escapes 

 infection owing, supposedly, to its small size, smooth bark, and comparative 

 freedom from insect attack. 



Crosses of chinquapin with Japanese chestnut have shown a hopeful degree 

 of resistance or of recuperative power, and some of these show considerable 

 promise as nut producex'S in regard to quantity and quality, early ripening, and 

 vigor of the trees. Observations and tests are still in progress. 



New hosts for Razoumofskya americana and R. occidentalis abietina, 

 J. R. Weir (Phytopathology, 1 (1917), No. 2, p. /,//0).— The author reports the 

 occurrence of R. americana on Pinus attenuata and of R, occidentalis abietina 

 on Abies nobilis and A. amabilis. 



