5 



EFFECT OF GROWTH HABIT ON FORM OF ROOT 



SYSTEM. 



The ability of a vine to make use of moisture in the soil is 

 governed by the scope of its sensitiveness to coldness and warmth. 

 A vine can take advantage of favorable moisture conditions only, 

 if the soil at the same time has the proper degree of temperature, 

 as prescribed by its scope of sensitivesess. By this we must realize 

 what an influence the latter has on the direction the roots take 

 especially with vines having a variable root system. But it also 

 influences vines in this respect to some extent, which have a fixed 

 deep or shallow root system. A Champini and considering only 

 the scope of sensitiveness of its root, also the Lenoir would fail 

 in a cold soil, where a Rupestris St. George with its freer root 

 would succeed. But the Lenoir has an advantage over the other 

 two hybrids on such a soil in having a more variable and more 

 expansive root system and also a peculiar combination which it 

 appears can not be reproduced again in grafting on it. The 

 first-named two might also fail in a coarse gravelly soil even if 

 this is warm, because their root action is too sluggish to absorb 

 the quickly disappearing and settling moisture as well as a 

 Rnpestris St. George. Its peculiar scope of sensitiveness to tem- 

 perature conditions causes the Lenoir to make both deep and 

 horizontal main roots on the colder soils and on warm gravelly 

 ones mostly horizontal main roots and deep laterals, almost the 

 opposite to what Viniferas have on such soils. The form of root 

 system of the latter for these two different kinds of soils, horizontal 

 main roots for cold soils and deeper main roots for gravelly ones, 

 is productive of the largest growth, but is not the hardiest. The 

 ungrafted Lenoir has a better root system in this respect for clays 

 and the Rupestris St. George for gravelly soils. In order that a 

 vine with only vertical main roots should succeed well on a clay, 

 it must be an exceedingly free grower. Although the laterals 

 develop somewhat more, they never spread very far. Even the 

 Rupestris St. George's root growth is not free enough to go 

 down deeply in a stiff clay and not because its roots could not 

 force their way down early in the spring while the ground is 

 softened by spring moisture. Of course later in the season it 

 would require quite a stiff and active root to penetrate through 

 clay, while this is becoming drier. 



Young Lenoir vines, if standing on a clay, should be exceed- 

 ingly well cultivated in order to bring as many roots up to the 



