50 EXPERIMENT STATION RECOED. 



In experiments with tomatoes, sowing seed in flats and transferring tlie 

 plants to pots and repotting tliem two or tliree times was of decided advantage, 

 producing the main crop fully 3 weeks before those sown and set in the 

 usual way. 



Plant pathology, T. W. Kirk and A. H. Cockayne {Neiv Zeal. Depi. Agr. 

 Ann. Rpt., 10 (I90S), pp. 108-117, pis. 9, figs. 2).— A review is presented of the 

 plant diseases which have been investigated during the year covered by the 

 report, relatively little injury having been done to crops on account of the dry 

 weather. Notes are given on a few diseases that have not hitherto been exten- 

 sively reported upon, among them a clematis rust caused by JEckUum otagcnse, 

 an aster wilt due to Fusarium sp., and diseases of the apple, among which are 

 powdery mildew (Podosphwra leucotricha), apple scab {Ficsicladiuin dendriti- 

 cum), and a disease often confused with apple scab caused by Coniothecitim 

 chomatosporum. The die back of peaches, due to Clasterosporium curpophilum, 

 and peach leaf curl are described, after which an account is given of potato 

 blight, potato Rhizoctonia, etc. 



Notes on some fungus diseases of plants, G. Lxjstner (Ber. K. Lehranst. 

 Wein, Obst, a. (lartciilxiii (JcisciiJieim, 1907, pp. 322-330, figs. .'/). — Notes are 

 given on a disease of young apple trees due to Fusid'ium sp., the occurrence of 

 Gymnospordiigiiiin siihiiiw on fruits of the pear, a Gloeosporium disease of 

 cherries, a Nectria and Fusidium on the fruits of apple trees, dodder {Cuscuta 

 h(pulifonnis) on pear twigs, and the destruction of grape stakes by the fungus 

 Xijla ria h gpoxi/lon . 



Some notes on nonparasitic diseases in the summer of 1907, P. Graebneb 

 (Juhrcshev. Yer. Aiigcir. But.. J (1907), pp. 226-233). — Frost injury as a cause 

 of disease in plants is discussed, and the results of low temperatures in the 

 summer of 1907 on a number of species are shown. The effect of drought and 

 excessive moisture as contributing to disease are also commented upon. 



Injuries to plants due to hail and frost, G. Massee (Roy. Bot. Hard. Keiv, 

 Bui. Misc. J II form.. 1909, A'o. 2, pp. 53-55, pi. 1). — An account is given of in- 

 juries to plants due to hail and frost, and attention called to the fact that where 

 plants have been caught by spring frost they .should be protected by a covering 

 of some kind, so that they will gradually thaw out. When coA-eriug is im- 

 practicable, a thorough sitraying with cold water is often effective in preventing 

 rapid thawing. In the case of frost cracks or injury caused by hail, the 

 wounded iiarts of plants should be sprayed with Bordeaux mixture at intervals 

 until a callus is formed, to prevent the entrance of fungi. 



Infection experiments with. Erysiphe cichoracearum, G. M. Reed {Bui. 

 Univ. Wis., No. 250, pp. 337-.'iU)). — This is a thesis submitted for the degree of 

 doctor of philosojjhy. University of Wisconsin, and is in continuation of pre- 

 vious investigations (E. S. R., 20, p. 247) on the specialization, of the mildew 

 E. vichonn-earum. The author has made further experiments with this mildew 

 on the scpiash and tested its capacity for infecting a number of cucurbits be- 

 longing to other species. The mildew occurring on asters, which is the same 

 morphological species, as well as the mildew on grasses and a great many 

 other plants, were studied by means of infection experiments. 



The results of the experiments show that the foriu occurring on the squash 

 can be readily transmitted to at least 11 other species of cucurbits belonging to 

 7 different genera. The author was unable to transfer it to asters or golden- 

 rod, or vice versa, and so far as the investigations have gone, the form of 

 mildew occurring on cucurbits is the only one which is capable of infecting 

 plants belonging to more than one genus. In other instances the mildew was 

 found to be limited closely to a single genus. In the case of the rye mildew it 

 is limited to the genus Secale, and the form on the blue grass to species of Poa. 



