DISEASES OF PLANTS. 451 



The pycnidial stage of this fungus is linown as Cytospora cincta. Cultures 

 from botli forms develop on the A-arious media only conidia, which occur in 

 both open and closed pycnidia, but when the cultures of either form were in- 

 oculated on peach limbs both pycnidial and perithecial stromata finally 

 developed. 



Cultures of Valsa and Cytospora from apricot, cultivated cherry, wild cherry, 

 peach, and plum trees, when inoculated on peach trees produced similar 

 wounds. It is claimed that sufficient variations in the cultures from the five 

 hosts were found to warrant the formation of two distinct varieties of the 

 fungus, viz, V. leucostoma cincta n. var. on the cultivated and wild cherry and 

 the peach, and V. leucostoma rubescens n, var. on the apricot and plum. 



Fall applications of lime sulphur and Bordeaux mixture reduced the number 

 of twig infections, while the destruction of all dead and diseased limbs and 

 twigs and the excision of infected tissues on the branches and trunks materially 

 reduced the number of infections the following year. 



A bibliography is included. 



Spraying for the control of peach brown rot and scab, W. M. Scott (Ann. 

 Rpt. Mo. Bd. Hart., 3 (1009), VP. 256-266) .—In a paper read before the Mis- 

 souri State Horticultural Society, the author summarizes the results of work 

 done during 1909 at Fort Valley, Ga., in controlling peach brown rot, scab, and 

 curculio with lime-sulphur mixture (8:8:50) and arsenate of lead sprays, 

 previously reported from other sources (E. S. R., 23, pp. 150, 745). 



Control of pear blight on the Pacific coast, P. J. O'Gara (Better Fruit, 5 

 (1910), ^'os. 2, pp. 1,9-51, 51,-56; 5, pp. 30-',3, 52-57, figs. 8).— A discussion is 

 given of the history, origin, progressive dissemination on the Pacific coast, 

 characteristics, and methods of combating pear blight (Bacillus amylovorus) 

 on both pear and apple trees. 



Attention is called to the fact that the quince, wild crab apple (Pyrus rivu- 

 laris), hawthorne (Cratwgus douglasii), service berry (Amelanchier alnifolia), 

 mountain ash (Sorbus occidentalis), Christmas berry (Heteromeles arbuti- 

 folia), and other wild fruits belonging to the Pomacefe are more or less sub- 

 ject to this disease, while the loquat and some varieties of plums and apricots 

 are also attacked. 



The two main methods of infection are through the nectaries of the blossoms 

 and the tender tips of growing twigs or watershoots, but occasionally it enters 

 by means of growth cracks and crown galls directly into the tender, growing, 

 fleshy bark. 



It is claimed that the only way to control blight is to remove all cases of hold- 

 over canker before the blossoming period by a system of careful inspection and 

 pruning. Summer cutting of blight should always be done, but to be effective 

 it must be thoroughly done. In order to render the fight against this disease 

 easier, the trees should be pruned to the vase or open-head type, and all water- 

 shoots and fruit spurs kept off the body and main limbs of the tree, while 

 watershoots, whether from the crown of the tree or from the root system, and 

 crown galls should also be pruned off. It is also suggested that the use of 

 scions on resistant stocks, such as the Winter Nelis and Kieffer, be used as a 

 means of combating this disease. 



Silver-leaf disease, F. T. Brooks (Gard. Chron., 3. ser., 1,8 (1910), No. 

 1248, p. 395). — In a brief note on this disease the author states that he has 

 been unable to produce silvering in plum trees by inoculating uncontaminated 

 spores of Stereiim purpureum into healthy trees, but that the silvering may 

 possibly ensue the next year. 



Pure cultures of the mycelium of this fungus have also been used for in- 

 oculations, but sufiicient time has not yet elapsed for any results to appear. 



