352 EXPERIMENT STATION RECORD. [Vol. 37 



755). — Observations during recent years, on the fruit plantations of the eastern 

 counties, have shown tliat American gooseberry mildew has been reduced, and 

 in some places almost eradicated, by growers who have subjected their bushes 

 to a thorough tipping (cutting off and burning the diseased shoots), followed by 

 two or three thorough sprayings with lime-sulphur during the growing season. 

 The authors therefore undertook these experiments to ascertain how much the 

 disease could be reduced in a single season by spraying alone, employing for 

 this purpose the variety Whinham Industry, on the plats used by Brooks, 

 Petherbridge, and Spinks, as previously noted (E. S. R., 34, p. 846). The hand 

 pumps used gave a pressure of 60 lbs. per square inch and carried swivel noz- 

 zles set to spray almost vertically. 



The results show that 2.5 per cent lime-sulphur is, in certain seasons, capable 

 of reducing the American gooseberry mildew attack on the berries to less than 

 1 per cent even in case of a susceptible variety badly affected previously. The 

 first spraying should be applied before the primary outbreak in the .spring, 

 preferably the first week in April. Two more sprayings, three or four weeks 

 apart, should also be given. In 1916, the first week in May proved to be the 

 most suitable time for a single spraying. 



Thorough spraying reduces to a marked extent the disease on the shoots. 

 Tipping, as carried out commercially, is of little value on a thoroughly iufested 

 plantation in such a .season as the one in question. 



Mysterious vine disease, J. W. Jeffrey (Mo. Bui. Com. Hort. Cal., 5 (1916), 

 A^o. 11, pp. 416, 417). — A peculiar grapevine trouble has appeared in several 

 districts of California for each of the last three seasons. The vines start with 

 apparently normal vigor in spring but lose their leaves in midsununer, and 

 show later only a small, sickly leaf at each axil, the fruit meanwhile withering 

 away in an immature condition. Although weakened the .second season, the 

 vines may not die until the third season. No variety is inmiune. so far as 

 known. The trouble appears to be independent of soil and irrigation, though 

 a decay of the roots seems to precede the final death of the plant.s. 



The gray root fungus of cinchona, A. Rant (Bui. Jard. Bot. Buifenzorg, 

 2. aer.. No. 22 (1916), pp. 23, pis. S). — An account is given of observation and 

 experimentation on a gray root fungus on cinchona, which has been observed 

 to attack also a considerable number of other plants named. The organi.sm, 

 which appears to be transmitted through both soil and air, is considered as gen- 

 etically related to Graphiuni. 



Control of blacJi spot and brown spot in citrus, G. P. Darnell-Smith 

 (Agr. Gaz. N. S. IVfl/cs, 27 (1916), Xo. 12, p. 8.^-}).— Black spot (Phoma c-itri- 

 carpa) of oranges and brown spot (Colletotrichttm glceospohoidcs) of oranges 

 and mandarins have been dealt with during four years by O. Brooks at Erina, 

 and the results are briefly set forth. 



Of the spraying solutions tested, potassium sulphid and copper sulphate were 

 dropped after the first year, and formalin and lime-sulphur after the third 

 year, leaving Bordeaux mixture alone to be tested the fourth year. This prepa- 

 ration, at first used at a strength of 6 lbs. of copper isulphate with 4 lbs. of lime 

 in .50 gals, of water, can, according to subsequent tests, be reduced to half 

 that strength, or less, with complete safety. The lime should be freshly burnt 

 and the mixture applied as soon as made, the application to be precedetl by a 

 thorough pruning of all dead or diseased wood. 



Composition of citrus leaves at various stages of mottling, C. A. .Ie.nsen 

 (U. S. Dept. Agr., Jour. Agr. Research, 9 (1917), No. 6, pp. 157-166).— In 

 experiments carried on at the California Citrus substation at Riverside, the 

 author undertook to determine whether mottled citrus leaves show a deficiency 

 of the mineral elements directly affecting chloroi)hyll formation. 



