60 EXPERIMENT STATION RECORD. 



exi)eriiiientH witli riilturt's of Spliarv>!)HiH takt-n fnnii all tin- dtiicr tree^, with the 

 axfeption of the jjeach, were found to readily jtrodnce the l>lack rot of the apple 

 fruit. Two explanations are offered for this behavior, one that the apple fruit is a 

 very favorable medium for the growth of the different species, the other that Sph;e- 

 ropsis is not parasitic on all of the trees. As a result of his experiments, conducted 

 through o seasons, the author states that he has positive evidence that the Sph;er((i)sis 

 occurring on apple, pear, and hawthorn trees and on apple, pear, and (juince fruits 

 is one and the same species. The relation l)etween sun scald, sunburn, and canker 

 is shown, in- which it is believed that the canker fungus finds access to the living 

 tissues through such injuries as sun scald and sunl)urn. To prevent these injuries it 

 is recommended that trees be sprayed witli a winter wash composed of lime 30 ll)s., 

 tallow 4 lbs., salt 5 lljs., diluted with en(jugh water to make it spray readily. Experi- 

 ments for the control of the canker were continued, but as yet no definite results have 

 been oljtaineil. The recommendations of the previous year, in which good orchard 

 sanitation and si)raying witli Bonleau.x mixture is advised, are repeated. 



Accompanying the aj^i^le-tree canker, as mentioned in the previous report, is a 

 second fungus, McuyropJioma malonun. It resembles the canker fungus very closely, 

 except in the character of its spores. Inoculation experiments on both apple and 

 pear trees with cultures of Macroplnjma gave negative results. These, however, 

 should be repeated before deciding that the fungus is not parasitic. 



The author reports the occurrence of the pAirop)ean canker, Xcdria dilismna, up)on 

 apple trees in a number of portions of New York and in Nova Scotia, the preliminary 

 report ot which is given in E. S. II., 12, p. 262. 



Apple-tree cankers, F. H. Hall and W. Paddock {New York Slate Sla. Bid. 185, 

 jMjpiihir 1(1. , j/ji. 4, jilx. J). — This is a popular summary of the bulletin noted above. 



The canker i Rostrella disease ) of Coffea arabica, A. Zimmekmann [Medcd. 

 'S Lcuidii Plautvidain, J7 (1900), jijj. ^4-iJJ, fuj-s. 10) . — The author describes a canker 

 disease of coffee trees, shows that it is caused by a hitherto undescribed fungus, and 

 suggests methods of treatment. 



The disease is confined to the Java variety of coffee and usually attacks isolated 

 trees. 8o far it has lieen known to attack only trees at least 10 years old. A yellow- 

 ing and sudden drooping of the leaves indicates the i)resence of the disease, which is 

 further characterized by the development of brown patclies in the cortex of the stem 

 and larger limbs. Death follows soon after the leaves droop. The brown patches 

 may extend nearly around the tree and involve the entire cortex, including the 

 cambium layer. The mycelium has not been found in the wood. 



The fungus belongs to a hitherto unde.scribed genus of Ascomycetes, and the author 

 names it EodreUa coffea. Four forms of reproductive bodies are de\elo]jed, asco- 

 spores, macroconidia, microconidia, and a fourth form which the author calls rudi- 

 mentary microconidia, produced by the breaking up of hy])a' developed from thie 

 macroconidia and microconidia, each form being fully describe<l. 



Infection exjieriments were made l>v placing small portions of diseased tissue under 

 the corte.x of healthy trees or pieces of stem and later by inoculation with microco- 

 nidia. All the infections were successful and the checks uniformly remained free 

 from the disease. The characteristic symptoms appeared in from 4 to 8 days and 

 frequently all the spore forms were developed. Infection experiments made on the 

 leaves and young twigs, as well as on the older limbs and trunk, showed that in Very 

 moist air Rostrella coffea can develop on the leaves and young twigs of Coffea arabica 

 when fresh wounds are present, but that the disease is checked on the young parts by 

 the development of a cork layer. Hence the mjury to the trees is always caused 

 by* the disease attacking the stem or larger hmbs. 



Experiments en Coffea liberica showed that while the fungus made a weak growth 

 in fresh wornids on l)oth stem and leaves, the mycelium did not penetrate beyond 

 the wound. Open air experiments gave negative results. Experiments on shrubs 



