658 EXPERIMENT HiTATION RECORD. 



about 50 per cent of the fir trees growing in pure forests ou the lower plateaux 

 were attacked, and that ou the upper elevation scarcely a tree had escaped, 

 but so far as observation has been made none of the trees have been destroyed. 



An Investigation into the cause of this trouble led to the recognition of the 

 fungus, which has been called Phoma abietina, or more properly Fusicoccuin 

 abictiniiin. 



The effect of the fungus on the foliage and branches of the trees is described 

 at considerable length. The author states that while it undoubtedly causes a 

 reduction in the annual growth of the trees proportional to the percentage of 

 leaves attacked, yet it apparently does not cause the death of the trees. It is 

 believed that the severity of attack will diminish, as has been the case in a 

 number of other outbreaks of the fungus that are i*ecorded. 



The brown rot of the lemon, It. E. Smith et al. (Cfilifoniia Sta. Bui. 100, 

 pp. 72, pJ. J, figs. 30). — A detailed account is given of the brown rot of the 

 lemon due to Pi/tliiaci/stis citrophtliora, a preliminary description of which has 

 already been noted (E. S. K., IS, pp. 344). This fungus attacks and destroys 

 large quantities of lemons not only ou the tree but also in the packing house. 

 The fungus is described in detail and accounts given of experiments for its con- 

 trol. These includetl not only an investigation of the trees in the orchard and 

 the soil underneath them, but also the methods of handling the fruit while pre- 

 paring it for shipment. 



For the control of this disease the author recommends a cover crop in the 

 orchai'd in September or early October. Toward the end of the rainy season 

 this cover crop should be plowed under, and the orchaixl kept in clean cultiva- 

 tion, especially under the trees, during the summer. This will to a large extent 

 prevent the infection of the fruit. As a further precaution, the author recom- 

 mends the disinfection of the wash water by adding either formalin, perman- 

 ganate of potash, or copper sulphate, the last named being preferred as cheaper 

 and more efficient. Lemons infected in the orchard should be carefully elimi- 

 nated during picking and washing, and where any are found in the curing tents 

 the affected boxes should be carefully gone over and rotten lemons picked out, 

 as the disease spreads by contact. 



A short review of parasitic fungi of Ficus elastica, S. H. Koorders (Notizbl. 

 K. Bot. Gartru.s u. Mus. Brrlin. .', {1901). Xo. 'lO, pp. 291i-310). —Au annotated 

 list is given of 65 species of fungi that are known to occur as active parasites, 

 facultative parasites, or saprophytes on the rubber plant {Ficus elastica). 



The chrysanthemum ray blight, F. L. Stevens (Bot. Gaz., 44 (1907), Xo. .J, 

 pp. 2Jfl-2oH, figs. 15). — A description is given of a ray blight of cultivated chrys- 

 anthemums which was called to the author's attention late in 1906. The dis- 

 ease had been known for several years, recurring each year with increased 

 destructiveness. 



The symptoms of the disease are most conspicuous in the flower clusters, 

 which are usually attacked on one side either in the bud or during the various 

 stages of blooming. The affected blossoms change in color, cease to develop, and 

 wither, the discoloration proceeding from the base toward the tip of each indi- 

 vidual flower. If the disease be severe and the bud attacked while young, no 

 ray flowers will develop and the head will not open. If the disease appear later 

 one-half or two-thirds of the flowers may develop normally, thus rendering more 

 conspicuous the disease. The receptacle of the flower turns black and the 

 peduncles may be blackened for 1 or 2 cm. below the head. On affected plants 

 the stems are often blackene<l for several centimeters, in a I)and more or less 

 com])letely encircling the stem. 



A microscopical examination was made of the diseased flowers. A fungus was 

 isolated and passed through various cultures, and its characteristics are given. 



