4i6 



Also the location itself has often l)een found to favor the appearance 

 of tlie disease, since on field ridges with a gravelly underground, or declivi- 

 ties from which the water nms away (|uickly, often only dry rotted beets 

 are produced. The different varieties are proved to be susceptible to 

 different degrees ; the Vilmorin sugar beet is said to be especially sus- 

 ceptible ; varieties with smooth leaves spread flat on the ground and long 

 roots should be preferred in threatened regions'. 



Sasse-, as a result of his verv' thorough field experiments, states that 

 xapor and deep cultivation prevent the outbreak of dry rot. Opinions vary 

 greatly as to the influence of fertilization. In my opinion, the variation is 

 explained by the varying action of the same fertilizer on different fields, 

 and dependent on the weather. Fertilizers making the soils more porous, 

 increasing their capacity for warmth and decreasing their power for re- 

 taining water, tend to favor the development of dry rot; this can occur with 

 waste lime^ The same fertilizers are satisfactor)^ in heavy soils. Fertiliza- 

 tion with kainit has been most questioned. Tt is emphasized that the soil 

 will actually retain water better after fertilization with commercial manures, 

 i. e. offer greater resistance to the influence of drought, and yet not infre- 

 quently where kainit fertilization has ])ecn used, the first heart rot of the 

 beets will be found. 



Tn my opinion there is a natural explanation for this phenomenon. 

 Kainit tends to develop leaves extraordinarily; hence, with a continued dry 

 period, the extensive leaf area withdraws water very quickly from the root 

 system, causing an injurious concentration of the cell sap. Analyses have 

 shown that, with a high potassium content in the leaves, the dry rot appeared 

 more marked, the smaller the proportion of phosphoric acid present. 



Therefore, the choice of land which dries quickly may be a preventa- 

 tive measure for this disease. When the soil is light those materials, which 

 heat the soil (lime, separator ooze ) must not be given directly to the beets. 

 With the appearance of dangerous droughts, one should decrease the drain- 

 age since, ordinarily, it would not be practical to always water the crop. 

 A further condition should be considered, namely, whether the evaporation 

 of the plants can be reduced by removing the older leaves, or by shading 

 with straw mulching. 



h'AULTY Development of the Blossoms. 



Much oftener than is generally supposed, great atmospheric dryness 

 manifests itself in blossoms, especially double flowers. If specimens of the 

 same species with single and with double blossoms in the same position be 

 compared (fuchsias, petunias, tuberous begonias, roses, etc.), it will be 

 observed without exception that the single blossoms develop more rapidly 



1 Bartos, W.. Kinig-e Beobachtung-en liber die Herz- und Trockenfaule, cit. 

 CentralbL f. Bakteriologie 1899, p. 562. 



2 Sasse, Otto, Einige Beobachtiinsen aus dem praktischen Betriebe betreffs 

 Auftretens der Herz- oder Trockenfaule. Zeitschr. f. Pflanzenkrankh. 1894, p. 359. 



3 Richter, W., tjber die Beziehungen des Scheideschlamms zum Auftreten der 

 Herzfaule der Ruben. Zeitschr. f. Pflanzenkrankh. 1895, p. 51. 



