54 EXPERIMENT STATION RECORD. 



Brunissure of grapes; its cause and remedies, L. DKciKiLi.v {I'rorj. Ayr. ft ]'it. 

 [Ed. L' J'Jst) , J// [19U.3), No. 15, pp. 44'J-45^). — A di«;ussiou is given of some of tlie 

 supposed causes of this disease' among them various fungi, insects, the lack of nutrition, 

 the effect of overliearing, etc.; and u review is given in which it is shown that there 

 seems to be some relati(jnship between production and occurrence of tlie disease. 

 Differenc-es in susceptibility of varieties are also shown, those of the Vinifera, Labrusca, 

 and yKstivalis types being quite subject to disease, while liiparia, Berlandieri, and 

 Cordifolia are seldom or never attacked. The author seems to incline to the opinion 

 that this disease is due to a lack of nutrition as well as overV)earing. For its preven- 

 tion he recommends thinning grapes to prevent overproduction, and l)etter culti- 

 vation of the vines, furnishing tliem with an a])undance of water and fertilizers. 



The conidial form of the black-rot fungus, (t. Delackoix {(Joinpl. licnd. Acad. 

 Set. P(tri.^, isr> {1902), Xo. 26, pp. 1372-1374) -—In a previous publication (E. S. R., 

 13, i>. 386) the author described a conidial form of the l)lack-rot fungus {(iuignardia 

 bidiri'llii ) which he stated Avas more or less common in the United States and occa- 

 sionally met with under favorable conditions in France. Other investigators have 

 since contested the accuracy of this description, and the author gives an account of 

 investigations conducted during 1902 which have confirmed his previous conclusions. 



The bluing and the red rot of the -western yellow pine, H. von Schrenk 

 ( U. *S'. Dept. Agr., Bureau of Plant Industry Bnl. 36, pp. 40, pU. 14)- — An account is 

 given of the cause of the blue timber of dead wood of western yellow pine {Finus 

 po)idero.'<a) and the effect of the coloring on the value of the wood, together with a 

 description of the red rot of the same tree, the investigations being conducted with 

 special reference to the Black Hills Forest Reserve. As a result of ravages of the 

 pine bark beetle {Dendroetonus ponderosfc) a large amount of the bull pine has been 

 destroyed. This wood seems to have undergone certain changes which result in 

 its becoming of a decided bluish color. The effect of the insect attack is shown 

 by the changed appearance in the color of the leaves following the attacks of the 

 insects in July, August, and September. The leaves turn yellowish in color, the 

 bright green fading almost impercepti])ly, and later the yellow increases and is some- 

 times rejilaced by a reddish coloration. The third year the leaves drop from the 

 trees, when they are known as "black tops." Soon after the attack of the bark 

 beetles the wood of the pine begins to turn blue. This color at first is very faint but 

 soon becomes deeper. The first signs of this change in color are observed several 

 weeks after the attacks of the beetles at points on the trunk in the immediate vicinity 

 of the attack. The color develoj^s rapidly when once the tree is attacked, and 

 standing trees examined in July, 1902, showed signs of blue coloration in 3 weeks 

 after the appearance of the beetles. In general appearance the blue timber differs 

 but little from the sound wood except in its color. The wood dries very rapidly and 

 is said to become much tougher than green wood, and tests of the compression and 

 breaking strength showed that blue timber 2 years old was stronger than the green 

 timber. 



The blue color of the wood is due to the growth of a fungus in the wood cells and 

 it is believed that the fungus is the same as that descril)ed by Hartig as occurring in 

 Europe. This fungus {('eratostomeUa pilifera) occurs on coniferous woods, mostly on 

 pine and develops rapidly in the medullary rays of the timber. The mycelium of 

 the fungus can be readily observed in the split wood and the fruiting organs may be 

 seen on the surface of the wood on which it is growing. A technical description is 

 given of the fungus, its growth in various media, the dissemination of spores, and 

 nature of the color. So far all attempts at extracting the color have failed but inves- 

 tigations show that changes of some kind have taken place in the wood fiber, the 

 nature of which is not definitely understood. The changes brought about by this 

 fungus can hardly be called a decay as the wood is sound to all ordinary appearances, 

 and only after some time do the ordinary processes of decay set in. 



