1919] 



DISEASES OF PLANTS. 543 



native of Florida, as a largp number of samples of seed were free from 

 infection. 



Considerable reliable information in regard to the cause, occurrence of, and 

 plants affected with bacterial blight has been collected, and suggestions have 

 ))een given for the control of the disease. Many phases of the blight, unknown 

 at present, such as varietal susceptibility of the plants, the effect of soil type 

 and treatment on the disease, etc., are to be thoroughly studied until deter- 

 mined. Comparatively little disease was found among the tomatoes on which 

 the experiment was made, yet the disease was scattered among nearly all of 

 the varieties. 



Continued observations, previously reported (E. S. R., 39, p. 4.57), are being 

 made on buckeye rot of tomato fruit. Tlie work of the past year demonstrated 

 that infection of the fruit takes place through the soil. Since the preliminary 

 report on this disease, a wider distribution of the fungus has been observed. 



Reports are also given of the truck disease survey, with brief description 

 of the damage caused by the late, early, and bacterial blights of tlie Irish 

 potato, nailhead rust of tomato, blackheart of celery, Phomopsis fruit rot of 

 eggplant, Alternaria fruit spot of eggplant, and Cercospora leaf spot of pepper. 



Report of the acting Dominion botanist, J. H. Grisdale (Canada Expt. 

 Farms Rpt. 1918, pp. 38-41). — Brief summaries are given of the more important 

 lines of work carried on during the year covered by the report. 



At St. Catherines, Out, studies of the white pine blister rust occupied con- 

 siderable time, and a preliminary investigation was made of a strawberry root 

 disease which appears to have been rather widespread. 



At Charlottetown, P. E. I., potato spi'aying experiments for late blight were 

 continued, and it is held to have been established that not less than four appli- 

 cations of 4 : 4 : 40 Bordeaux mixture per season are necessary, though not quite 

 so effective in controlling the disease as six applications. For the control of 

 the blackleg disease of potatoes, experiments have shown that the whole tuber 

 should be treated with disinfectants and not the cut tuber. The disease appar- 

 ently is not carried over in the soil. Other investigations of potatoes have been 

 continued. 



At Fredericton, N. B., the work largely consisted of a series of potato spray- 

 ing experim'ents, carried on to determine the increase in yield due to freedom 

 from blight and the number of applications necessary. 



At the Brandon, Man., and Indian Head, Sask., laboratories the studies have 

 been mostly on grain rust and other cereal diseases. The principal investiga- 

 tions were made to determine the native and cultivated grasses which act as 

 host plants for the rust, the species of rusts attacking cereals in Western Can- 

 ada, and the origin of the outbreaks of rust. 



Mycology and plant pathology, E. J. Butler (Ami. Rpt. Bd. Sci. Advice 

 India, 1916-17, pp. ^7-50). — This includes, besides miscellaneous matters, an 

 account of the chief investigations at Pusa during the year. Plant diseases and 

 pests dealt with include ufra of rice, Orobanclie spp. on tobacco and other plants 

 (noting certain apparent specializations), Phytophthora investigations, studies 

 on Rhizoctonia and allied fungi, anthracnose of chili and other crops, and sal 

 tree disease. 



Plant diseases, C. M. Hutchinson {Ann. Rpt. Bd. Sci. Advice India, 1916-17, 

 p. 59). — The author states in this portion of a more general report that bac- 

 terial diseases of wheat, poppy, and citrus plants were under investigation dur- 

 ing the year. A memoir on bacterial diseases in wheat was projected, as was 

 also a description of bacterial rot of poppy, which resulted in a blackening and 

 slimy decay of the stem and leaves. Further study was contemplated of citrus 

 canker, which has been known in India for several years, some forms of this 



