DISEASES OF PLANTS. 47 



So far as the autlioi-'s observations have gone, the disease appears to run 

 its course with the first cutting. Little or no trace of the disease may be 

 found during the remainder of the season, but the following spring an aggra- 

 vated outbreak may be expected. The disease apparently does not kill many 

 plants the first year, but they begin to die after the blight has been prevalent 

 more than one; season, and after 2 or 3 years the stand is practically worthless. 

 It is thought that there is some relation between this disease and the pasturing 

 and irrigation of the alfalfa fields. The subject is to be given further investi- 

 gation. 



The author describes the pear blight, giving its characteristics, means of 

 spread, and methods for prevention and treatment. 



Plant diseases, A. E. Collens (Dcpt. Ayr. Trinidad, BiiJ. Agr. Inform., I'JOi), 

 n. ser., No. 61, pp. SS-J/S). — The author briefly describes the attack of Kutj/pa 

 erumpens on cacao, the fungus proving a destructive i)arasite. In addition 

 to this host it is also known to attack banyan trees, mangoes, lilchi trees, and 

 various forest species. The presence of the fungus may be recognized by the 

 occuri-ence of iri-egular black patches on the bark with a dull grainy surface. 



Notes are given on the occurrence of Diplodia cacaoicola on grape cuttings 

 and D. maydi.s on Indian corn. The fruiting stage of Ncctria theohroma; 

 has also been found on exposed roots of (iliricidia maculata and stems of 

 mangoes and avocados, all of which were growing near cacao trees affected by 

 the disease. 



A tabulated account is presented of th(> fungus and insect pests of cacao, in 

 which descriptions are given of the parts affected and the symi)toms, with sug- 

 gestions for control. Similar data are given for the principal diseases of 

 sugar cane. 



The life history of the cedar rust fungus, F. D. Heald (Nebraska Sta. Rpi. 

 J908, pp. 103-121, pin. 13, map I). — Attention is called to the general prevalence 

 of cedar lust throughout the eastern half of the State and the relation of this 

 disease to aitple rust. The great abundance of the disease in Nebraska is said 

 to be due, in part at least, to the general practice of employing cedars as 

 ornamental trees or for wind-breaks, and also the extensive planting of such 

 varieties of apples as Wealthy and .loiuithiui, which are especially susceptible 

 to the disease. 



The cedar rust fungus {(lymnosporangium juniperi-virginiance) spends one 

 stage of its life history on the cedar, producing the so-called cedar aj)ples, the 

 other upon the leaves and fruit of the apple tree. The different stages of the 

 fungus are described at length, and on the basis of liis observations, the author 

 summarizes the life history of the fungus, stating that the galls are produced 

 on the cedar in May and that the teliospores germinate and produce sporidia 

 which infect the aiiple trees during the next few days. The first aecidia become 

 mature during July and viable spores are produced during this and the two fol- 

 lowing months. These spores infect the cedar, but no visible signs can be noted. 

 The mycelium apparently remains dormant during the winter and with the 

 resumption of growth in the spring the fungus stimulates the cedar at the 

 point of infection and the result is the formation of cedar apples, which first 

 become visible in the month of June. These cedar apples grow throughout the 

 summer and fall, remain dormant during the winter, and with the return of 

 favorable conditions in the spring produce the characteristic gelatinous masses. 

 From this it will be seen that 23 months elapse from the time of the infection 

 of the cedar to the period when the resultant galls produce the gelatinous spore 

 masses. 



Spraying experiments have been carried on with varying degrees of success, 

 and it is said that the practical ai)plication of spraying cedars for the proven- 



