548 EXPERIMENT STATION RECORD. [Vol. 35 



of apple branches, in which areas of dead bark infested with Coniothyrium 

 fuckeUi surround oviposition punctures of tree crickets. 



The constant association of this fungus with such cankers led to an investi- 

 gation of tree crickets as its carriers. It was found that tree crickets may 

 carry the fungus from raspberries to apple trees and infect them, and also that 

 they may carry the spores of these and other fungi in the digestive tract 

 as well as on the outside of their bodies. Feeding experiments showed that 

 the spores of Ustilago zece, Coprinus micaceus, Coniotliyrium fuckelii, Num- 

 mularia discreta, and Sphceropsis malorum passed through the digestive tract 

 of tree crickets without loss of viability. 



Typical cankers resulted when tree crickets fed on C. fuckeUi were allowed to 

 oviposit on apple branches. The percentage of cankers formed about oviposition 

 punctures was considerably greater when the crickets were fed with C. fuckeUi 

 from raspberry canes than when they were fed with pure cultures of the fungus 

 isolated from apple branches. The oviposition punctures of (Eca-nthus nivcus gave 

 a higher percentage of infection than those of GE. angustipeunis, and for both 

 species the percentage of infection was considerably higher when the punctures 

 were covered with grafting wax than when left uncovered. Typical cankers were 

 also produced by inserting pellets of tree-cricket excrement into punctures made 

 in apple branches and covering them with grafting wax. 



Clean cultivation and the use of arsenical sprays are suggested as remedial 

 measures for the control of tree crickets. 



Collar blight of apple trees, C. R. Okton and J. F. Adams (Pennsylvania 

 8ta. Rpt. 191 Jf, pp. 152-160, pis. S). — This is an account of an investigation of 

 collar blight of apple trees, due to the organism Bacillus amylovorus, a more 

 extended report of which has been noted (E. S. R., 34, p. 247). 



The spraying- experiments of 1915 in the Hood River Valley for the con- 

 trol of apple scab, J. R. Winston and L. Childs {Oregon Sta., Rpt. Hood River 

 Sta. 1915, pp. 30--'f6, figs. 5). — A report is given of experiments carried on in the 

 Hood River Valley for the control of apple scab which, in the last few years, 

 has become a very serious pest in this region. In 1914, cooperative experiments 

 were carried on with a number of growers, and in 1915 work was continued 

 on three orchards in which Winesap and Newtown apple trees were sprayed 

 with various fungicides to test their efficiency. Bordeaux mixture, soluble sul- 

 phur, barium tetrasulphid, atomic sulphur, and iron sulphid were tested in 

 comparison with lime-sulphur solution. In addition, the time of application was 

 studied, particular attention being paid to the delayed dormant application, in 

 which trees were sprayed with a rather strong lime-sulphur solution .iust as the 

 leaves were beginning to show from the winter buds. 



The delayed dormant application proved valuable in some instances, increas- 

 ing by about 12 per cent the sound fruit. Lime-sulphur proved the most efficient 

 fungicide tested, the addition of atomic sulphur in one instance apparently de- 

 creasing its fungicidal properties, and the addition of iron sulphid apparently 

 decreasing the fungicidal properties and slightly increasing the injurious quali- 

 ties. Bordeaux mixture caused serious russeting of the fruit. The barium tetra- 

 sulphid used in strengths recommended by the manufacturers did not prove so 

 efficient as lime-sulphur in controlling scab. Atomic sulphur proved a very 

 poor substitute for lime-sulphur in the later applications. Soluble sulphur was 

 less efficient and decidedly more injurious than lime-sulphur, but it was more 

 efficient than atomic sulphur, iron sulphid, or barium tetrasulphid. 



Based on two years' work, the authors claim that by thorough application 

 of fungicides apple scab may be controlled in the Hood River Valley, even in 

 years favorable to epidemics of the disease. A tentative spray calendar for 



