DISEASES OF PLANTS. 545 



[Coffee diseases in Uganda], T. D. Maitland {Ann. Rpt. Dept. Agr. Uganda, 

 1914. pp. 18, 19). — Coffee leaf disease (Hemileia vastatrix) was checked and 

 almost eradicated by uprooting the older coffee trees and spraying the younger 

 with Bordeaux and Burgundy mixtures as soon as the growing season set in. 



A die-back, apparently a secondary condition resulting from the effects of the 

 leaf disease, was even more serious than that disease itself. Cutting back 

 beyond the dead portion was not effective in arresting the disease, but manurial 

 treatment and rain arrested the die-back, apparently proving its constitutional 

 character. 



Changes in coffee grains due to Aspergillus, L. Beille {Proc. Verb. Soc. 

 Set. Phijs. et Nat. Bordeaii.v, 1912-13, pp. 37, 38).— The author has found in 

 coffee from Haiti two fungi, connected with a stinking rot of the grains, which 

 appear to be closely related to or identical with A. nigcr and A. flavus. Two 

 other organisms causing injury to coffee seeds appear to belong to the same 

 genus, but could not be identified with those above named. 



Diseases of lime trees in forest districts, W. Nowell (Imp. Dept. Agr. West 

 Indies Pamphlet 79 {1915), pp. 41, pis. 5, figs. 2; abs. in Agr. Neivs [Barhados], 

 14 {1915), No. 349, p. 302). — This is a popular discussion of the black root dis- 

 ease due to RoselUnia pepo or R. bunodes, which may infect the trees by spores 

 or by contact, protection from these fungi requiring careful inspection, isolation 

 as regards contact, destruction of diseased material, and the use of lime and 

 sulphur in the soil as auxiliary agents ; red root disease, which is also known 

 to spread by means of underground strands, requiring substantially the same 

 treatment as *he foregoing; and pink disease, observed to cause a certain 

 amount of twig blight in sheltered cleanings on estates having a high rainfall. 



Walnut blight or bacteriosis, C. O. Smith {Mo. Bui. Com. Hort. Cal., 4 

 {1915), No. 5-6, pp. 254-258, fig. 1). — Describing the walnut blight due to 

 Pseudomonas juglandis, said to have caused losses in California during about 

 25 years, varying with conditions up to 50 per cent in some cases, the author 

 states that the chief injury is done to the nuts, which are attacked when young, 

 principally at the blossom end or stigma where the surface is not covered with 

 epidermis. Older nuts usually suffer less injury from attacks, which are 

 mainly at other points. Leaves, shoots, and young nursery stock may be 

 attacked, but the chief damage in such cases appears to be that resulting 

 from the consequent dissemination of the disease. 



The organism appears to winter in the bark, wood, and possibly the pith of 

 diseased branches, becoming active after the sap starts in the spring, and giving 

 rise to a rather sudden and severe secondary infection. The organism can live 

 over in cloudy weather for several days on the surface of diseased nuts, and 

 is said to be able to withstand from 20 tg 50 days of drying in the absence of 

 sunlight. Successful inoculations have been made on Juglans nigra, J. califor- 

 nica, J. hindsii, J. cinerea, J. cordiformis, and J. sieboldiana, also on certain 

 hybrids. 



Some spraying experiments with Bordeaux mixture reduced by one-half the 

 number of blighted nuts, while other tests with that fungicide and still others 

 with a mixture of sulphur and potassium hydrate had no perceptible effect. 

 Lime sulphur was not entirely effective, but in some tests a marked reduction 

 of blight was perceptible the second year. The total expense with modern 

 equipment has been reduced to about 50 cts. per tree. 



An observed difference between individual trees is thought to indicate their 

 strong resistance or immunity to this disease. 



The persistence of viable pycnospores of the chestnut blight fungus on 

 normal bark below lesions, R. A. Studhalter and F. D. Heald (Amer. Jour. 

 Bot., 2 {1915), No. 4, pp. 162-168).— It is stated that viable pycnospores of 



