DISEASES OF PLANTS. 247 



otliers, Cleopatra suffering most of all varieties and Yates least. The disease 

 lias been known in Australia since 18S6. It is worse on a light crop of large 

 fruit or in case of trees severely pruned, and in wet seasons. It appears to be 

 favored by intermittent weather conditions, sudden checking of transpiration 

 at night, inequality of growth (interfering with the development of the vascular 

 network controlling the distributi*n of the nutritive material), intermittent 

 stimulation during growth of the fruit, late gathering of the fruit, and fluctua- 

 tions of temperature and humidity when in store or transit. 



It is thought that moderate pruning, admitting light at the top, and grafting 

 new varieties will prove beneficial. Cool storage was followed by excellent 

 results, as apples kept at 34° F. for four months showed no sign of bitter pit. 

 It is said, however, that when the temperature falls below the point where 

 respiration ceases, danger results. Apparently the most satisfactoi-y tempera- 

 tures are those between 31 and 34°. It is found necessary also to keep the 

 carbon dioxid drawn off and to provide for free circulation of air through the 

 cases. 



Apple scab situation, D. Eeddick {West. N. Y. Hart. Soc. Proc, 58 {1912), 

 pp. SG-90). — It is held that the slight damage from apple scab in 1911 was due 

 to the fact that the showers were of short duration, sufficient to cause a dis- 

 charge of spores from the winter fruit bodies of the fungus but not prolonged 

 enough to hold the moisture necessary for spore germination, and to the fact 

 that high winds shook the drops from the leaves and quickly dried the sur- 

 faces. The resulting small number of infected leaves left over during the 

 winter is believed to account for the low rate of infection in 1912. The usual 

 vigilance however is recommended, as comparatively little inTectiou is apt with 

 favorable rains to result in severe injury to the apple crop. 



Ti'iclioseptoria fructigena, a disease of quinces and apples new in Germany, 

 W. PiETscH {Ber. Deut. Bot. GeseU., 31 {1913), No. 1, pp. 12-1-i).— The author 

 claims to have found that T. fructigena, previously shown by Maublane (E. g. 

 R., 26, p. 449) to attack apples, has a somewhat wide distribution, but that the 

 fruit of Cydonia vulgaris is its principal substratum. C. japonica appears to be 

 immune to this fungus. 



A momentous discovery for fruit growers, E. Walker {Country Life [Loit- 

 don], S3 {1013), No. 852, pp. 6U, 6^5).— The author reports the presence of a 

 disease of pears which results in the discoloration and blackening of the 

 flowers and foliage and which is api)arently the same as the bacterial or fire 

 blight of pears. In addition it is stated that the bacteria accompanying the 

 disease have been found in nurseries and plantations on apples and plums. 



Beport of former plant pathologist, H. S. Fawcett {Florida Sta. Rpt. 1912, 

 pp. LXIV-LXXIII, LXXVII-XCII).--The author gives a detailed account of 

 cultural, infection, and control work with the fungus Phomopsis citri, the cause 

 of stem-end rot, which has previously been partially reported upon (E. S. R., 

 26, p. 449; 28, p. 549). Spraying tests are noted on page 248. 



An account is given of an experiment conducted to determine the cause of 

 gumming or gummosis. Two different forms of gumming were found, one of 

 which has been described as due to Diplodla natalensis (E. S. R., 27, p. 350). 

 Inoculation experiments were made with P. citri, Colletotriclium glceospori- 

 oides, Sphcei'opsis tumefaciens, Alternaria citri, and Alternaria sp. isolated from 

 leaves, and Cladosporiuni herharum, 8. malornm, and Fu-^ioriuni gramineum 

 from other sources. Of these, P. citri induced gumming, which was about half 

 as copious as that due to Diplodia. The Fusarium produced still less, and A. 

 citri and Colletotrichum glceosporioides induced only slight amounts of gum. 

 The other species had no effect in this respect. Experiments were made with 

 bacteria from various sources, but none of the bacteria produced gumming wheJi 



