g52 EXPEKIMENT STATION RECOED. 



{1915), No. 7, pp. 189-284, pis. 7). — This is an extended study of Bacterium 

 vascularum in its causative relation witli gummosis of sugar cane, wliich is de- 

 scribed in connection witli associated factors and conditions. A bibliography 

 is appended. 



The new disease or dry disease of the sugar cane, C. K. Bancroft {Jour. Bd. 

 Agr. Brit. Guiana, 1 {19U), No. 4, pp. 183-187; abs. in Internat. Inst. Agr. 

 [Rome], Mo. Bui. Agr. Intel, and Plant Diseases, 5 {1914), No. 9, p. 1241). — 

 The symptoms, progress, and effects of this disease are described. It is said 

 to have been observed first in this colony in 1907, but to have spread since that 

 time to estates elsewhere, its progress being apparently slow and its tenure 

 uncertain in some localities. 



Investigations have borne out the conclusions of Stockdale (E. S. R., 32, p. 

 441) inasmuch as Marasimus sacchari was found in what was probably a 

 causal connection with the disease. It is said to be propagated by spores, 

 underground mycelium, diseased cuttings, etc. 



Control measures include drainage and cultivation for increased vigor, aban- 

 donment of ratooning, change of crops, isolation by means of trenches, sanitary 

 measures (as the employment of lime), and the use of resistant A'arieties named. 



Occurrence of Thielavia basicola as a root parasite of watermelons in the 

 Salt Lake Valley, Utah, P. J. O'Gara {Science, n. ser., 42 {1915), No. 1079, 

 p. 314). — The author reports having observed T. basicola parasitic on roots of 

 watermelons. He believes that this is the first case in which it has been found 

 as an active parasite in any part of the United States west of the Mississippi 

 River. 



Bitter pit, its cause and cure, D. McAlpine {Fruit World Austral., 15 

 {1914), Nos. 5, pp. 143-153, figs. 21; 6, pp. 179-187, figs. 10; 7, pp. 215-222, 

 figg^ 7). — ^A summary is given of the second report on the bitter pit of apples 

 (B. S. R., 31, p; 244), dealing principally with the cause of bitter pit, factors 

 that contribute to its development, and methods for its control. 



Fluctuating conditions of temperature and humidity are said to be the 

 principal contributing factors in the development of this disease. There is 

 also said to be a distinct relation between the sj-stem of pruning and the 

 prevalence of bitter pit. The transpiration of the fruit as affected by various 

 factors, such as pruning, manuring, cultivation, etc., is discussed at length. 



The control of bitter pit in the growing fruit, D. McAxpine {Prog. Rpt. 

 Bitter Pit Invest. [A»st], 3 {1913-14), j>p. 176, pis. 7/3).— This is the third 

 progress report on bitter pit (see above). The investigation, which is still 

 in progress, has now been extended to influences of many kinds affecting the 

 trees and the fruit both before and after it is gathered, as related to bitter pit 

 injury. The question as to whether bitter pit originates only while the fruit 

 is yet on the tree is still unsettled. 



It has been found that the increase of transpiration in the growing fruit is 

 referable to the increase of its transpiring surface and the decrease in humidity 

 of the air at this season of the year in this region. Fruit borne on laterals 

 remained free from the disease even when the rest of the fruit on the tree 

 was badly pitted. 



Biochemical tests of growing fruit and X-ray studies of stored apples are 

 being made to determine the inception and developmental conditions of bitter 

 pit. It has been established that an excessive flow of sap toward the fruit 

 causes a tendency to pit. This is lessened or neutralized by checking the 

 sap flow, for which purpose constriction is being tested. Severe cutting back 

 for grafting purposes resulted in one case in the pitting of 92 per cent of the 

 apples borne on the remaining branches, while neighboring trees on which only 



