754 EXPERIMENT STATION RECOED. [Vol.35 



Cupro-ferric sprays for downy mildew and cMorosis, A. Donadietj (Prog. 

 Agr. et Vit {Ed. VEst-Centrs), 37 (1916), No. 12, pp. 271, 272).— Responding to 

 inquiries regarding tlie treatment above mentioned, tlie author gives tlie 

 formula employed. This requires 2,000 gm. copper sulphate and from 750 to 

 800 gm. sodium carbonate in 100 liters of water, with the addition, when the 

 above has been properly made up, of 100 gm. iron sulphate. 



Treatments for downy mildew and the preparation of copper sprays, L. 

 Degbxjlly (Prog. Agr. et Vit. (Ed. I'Est-Centre), 37 (1916), No. U, pp. 317- 

 S24). — Enlarging on the statement that the experience of 1915 showed that cop- 

 per does not necessarily constitute an ideal remedy for mildew, at least under 

 the usual forms and conditions recently found in actual practice, the author 

 discusses the great influence of the time factor as related to outbreaks; the 

 duration of the effectiveness of one spraying (in 1915 not over four to five 

 days) ; the suitable preparation of sprays and the proper dosage thereof; the 

 acid, alkaline, neutral, and casein preparations of Bordeaux and several 

 other preparations. It is stated that in regions severely attacked in 1913 to 1915 

 only those grape growers saved their entire product who employed treatment 

 without intermission throughout the whole of the danger period. 



Mottle leaf of citrus trees in relation to soil conditions, L. J. Bbiggs, C. A. 

 Jensen, and J. W. McLane (t7. S. Dept. Agr., Jour. Agr. Research,, 6 (1916), 

 No. 19, pp. 721-740, pis. 3, figs. 4)- — The authors report a study of the cause of 

 mottle leaf of citrus trees which is characterized by the disappearance of the 

 chlorophyll of parts of leaves. The principal conclusion of their investiga- 

 tion is that the mottling of orange trees in the areas studied is definitely cor- 

 related with a low humus content of the soil, the mottling diminishing as the 

 humus content increases. It is claimed that approximately one-half of the 

 mottling can be accounted for in this way and that the incorporation of 

 organic matter with the soil in such a manner as to be readily accessible to the 

 roots during its decomposition is a promising treatment for this trouble. 



Fighting a fungus, Pythiacystis citropMhora, in the citrus orchards, H. S. 

 Fawcett (Univ. Cal. Jour. Agr., 3 (1916), No. 8, pp. 339-343, 356 figs. 3).— The 

 fungus P. oitrophthora, isolated and described by Smith in 1906 as the cause 

 of brown rot of lemons (E. S. R., 19, p. 658) and shown by the present author 

 in 1913 (E. S. R., 30, p. 51) to cause also a form of gummosis in the bark, 

 is here discussed as to the conditions, modes, and consequences of its attack, 

 and as to its control. 



Bordeaux mixture as a spray is deemed practically preventive, as is also 

 fresh Bordeaux paste in connection with surgery when the trunk is attacked, 

 which usually occurs near the surface of the ground. Sour orange is very 

 resistant and desirable to use for stocks. These should, however, be budded 

 high and so planted as to keep the bud unions as far as possible from the 

 surface of the ground. 



A serious disease of cultivated perennials caused by Sclerotium rolfsii, 

 G. L. Peltier (Illinois Sta. Circ. 187 (1916), pp. 4, fig- i).— It i" stated that 

 during the summer of 1915 a large number of perennial ornamental plants 

 were found dying from crown rot. An investigation of the disease showed that 

 it was due to the fungus S. rolfsii. The disease is said to have made its first 

 appearance in .July and to have killed a large number of plants during the 

 warm weather. It persisted until late in October, although with cooler weather 

 the attack became less severe. Among the ornamentals attacked were several 

 species of Campanula, Phlox, Dianthus, Eupatorium, etc. The outbreak of 

 the disease is attributed to the extremely wet summer, and it is considered 

 doubtful whether, under normal conditions, the disease will ever become serious 

 in Illinois. 



