DISEASES OF PLANTS. 1 1 65 



The leal' anthracnose, caused by Pestalozzia funerea, made it- appearance early in 

 .Inly, when black, velvety patches were observed at the bases of the leaves and 

 flower stalk- causing them to die and tall off. This form of anthracnose caused the 

 death of thousands of young plant-, and it was found thai italso could be kepi in 

 check by spraying with Bordeaux mixture. 



The wilt disease described is due to Neocosmoepora vasinfecta, and this trouble has 

 proved a very serious one, whole plantations often being destroyed in a single week. 

 As the name suggests, the disease i- to be recognized by the wilted appearance of the 

 plants, and in this re-pert it greatlj resembles the wilt of cotton, watermelon, and 

 cowpeas. In fact, the fungus i- considered identical with thai causing the will ol 

 these plants. 



The author investigated the entrance of the fungus through the roots, bul a care- 

 ful examination failed to show any signs of fungus infection. There was evidence, 

 however, for believing that the fungus enters the plant at the base of the Btem 

 through the lesions caused by the Btem anthracnose. This is shown from the facts 

 that careful microscopical examination tailed to reveal the presence of any fungi in 

 the young parts of the root-, that where a- a resull of Bpraying there was no anthrac- 

 nose fungus the plants were not affected by the wilt, and that the wilt disease never 

 appeared until about 2 months after the stem anthracnose had made its appearance. 



The fungus ia not found except in the fibrovascular bundles while the plant is 

 alive, while it is very customary to find the spore balls in the interior of dead, hollow 

 stems, etc. The observations of the author have led to the conclusion that the wilt 

 disease can be controlled by keeping the plants im- from anthracnose and other fungi 

 which produce lesions on the stems. 



A technical account is given of the diseases and of the fungi causing them. 



A Ph/tophthora rot of apples, etc., A. ( )stekw.\i.m:i; I ( '< nihl. Bald, [etc.'}, .'. Abt., 

 15 [1905), No. 18-14, }'/>■ 485, 440). — Following a severe rain and hailstorm in June. 

 1904, apples were found affected with an unusual rot. Upon investigation the cause 

 was determined to be Phytophthora omnivora, and inoculation experiments showed the 

 possibility of its causing the rotting of apples and pears within a relatively short time. 



Notes on the so-called closed canker of apple trees, K. vox Ti 1:1:1 i ( Naiurw. 

 Ztschr. Land ". Forstw., 3 (1905), No. /, pp. 92-94, figs. ?).— The author describee an 

 unusual form of apple-tree canker, in which the fungus stimulates the tree into the 

 production of large knotty outgrowths. When sawed through, the perethecia of 

 Nectria ditissima were found inside the knots. 



A bacterial disease of cherry trees, R. Adbbhold and \V. Ruhland I Centbl. 

 Bakt. [etc.], j. Abt., 15 {1905), No. i. J . pp. 876, 871 I. A preliminary note is given on 

 a bacterial disease of cherry trees that has been quite destructive in some of the Rhine 

 provinces of Germany. 



This disease appears to have been hitherto confused with that described a- due to the 



fungus Valsaleucostomd (E.S. R., 15, p. 270), but it lacks the characteristic outgrowths 



of that disease. The organism has been isolated and cultivated, and inoculation 

 experiments show that it is capable of causing the trouble. The bacterium is described 

 by the authors as Ilud/lns spongiosus. The di-ea-e i- believed t.> be widely distrib- 

 uted throughout < iermanv. The authors intend further studies Upon it. and BUggeet 

 that it may also attack other stone and pomaceous fruit tree-, a- -imilar appearances 

 have already been noticed on plum and apple trees in the vicinity of I temmkrug. 



Observations on the biology of the olive-tubercle organism, E. I\ Smith 

 [Centbl Bakt. [etc.], 9. Abt., (5 {1905), A'-. ; 8, /</<. 198 WO, pi. t).- The author was 

 led to investigate the organism causing the olive knot i Bacillus o/-c«), to confirm state- 

 ments by Schiff I E. s. b., L6, p. 987) relating to the biology of the bacillus. 



The organism was isolated from olive knots from California, and studied under 

 various conditions, comparisons being made with organisms plated out from material 

 received from two different source.- in Italy. In all of the material examined there 



