537 



Drainage will naturally act as a precautionary method. A loosening 

 of moor soil by raking it over with sand may also be proved favorable. 

 Kuhn\ in this connection, found that drill cultivation was also effective 

 since all seeds were thus hoed in again. Between these seeds are produced 

 thereby "small grooxes into which the moisture chiefly passes and thus, 

 under the conditions cited, an upraising (jf the soil is observed in the s])aces 

 between the plant rows, while the jjlant rows themselves remain untouched." 

 Hedwig- recommends early sowing in order to obtain as abundant deep 

 growing roots as possil)le and therel>y to secure the plants more firmly in 

 the soil. 



Ekkert' recommends a surface sowing, but chiefly the growing of 

 strong plants. In favoring this surface sowing, Ekkert seems to have been 

 influenced by the statements of Count Pinto-Mettkau, who says that only 

 seeds which lie deep are heaved out of the soil and, in this are torn at the 

 base of the primary internode, i. e., at the i)art of the stem which is strongly 

 elongated onl)- in deep sowing and wliich raises the node of the i)lant toward 

 the upper surface of the soil. This theory is shared also by Breymann'. 

 Ekkert's investigations on the firmness and elasticity of this lowest part of 

 the stem and of the roots fa\or the view that, in this heaving from the soil, 

 the roots are torn sooner than the internodes. With surface sowing, it is 

 possible that only the roots will be torn and the superficially lying grain, 

 therefore, also carried up so that it will still remain as a possible retainer of 

 reserve substances for the injured plant. The injury would consequently 

 be less and more easily overcome with the additional help of a rapidly 

 eft'ective spring fertilizing. 



Johannes rye has been recommended as a resistant variety. In wheat. 

 a Russian variety, (■rtoha ivlicaf. is f(jund to be especially resistant. How- 

 ever, neither variety nor depth of sowing will determine this in the end, but 

 chiefly the constitution of the soil and its power to retain water become of 

 especial importance. 



In young tree plantations, the heaving of the seed occurs also with 

 black frost. The seedlings of pines and oaks, provided with strong, long 

 tap roots, did not suffer, but those of the superficially rooting spruce and 

 hemlock arid, among many deciduous trees, the black alder in boggy soils, 

 do so. 



Internal Injuries in Young Grain. 



As yet, no attention has been paid to the fact that grain plants suffer 

 internal injuries from black frosts, even if they are not heaved from the 

 soil. These injuries, with continued wet weather, form convenient centres 

 for the attack of parasitic fungi. Besides the common black fungi, we will 



I Krankheiten der Kultiiipflanzen 1S59, p. 11, 



- cit. in Giippeit, Warmeentwicklung-, etc., p. 236. 



'■'■ Ekkert, tJber Keimung, Bestoekung und Bewurzelung der Getreidearten, etc. 

 Inauguraldissertation, Leipzig-, 1874; cit. in Biedermann's Centralbl. 1875, p. 204. 



■i tJber das Auswintorn des Weizens, des Rapses und des Rotklees. Bieder- 

 mann's Centralbl. 1. Agrikulturchemie 1881, p. 829. 



