SC'IEXTIFIC AGRICULTURE 



November. 1921 



the extreme early varieties and the extreme 

 late varieties. The essential differences 

 between the two groups, however, are in 

 reality n€t earliness or lateness, but rather 

 mode of growth and development in gen- 

 eral. 



Early Red Clover (Trifolium pratense 

 praecox) is characterized by comparatively 

 little branched stems. The branches of the 

 stem are generally only 2-4 in number and 

 reach the same |ieight as the stem itself. 

 As a result the heads are all borne on about 

 the same level, a fact which makes a flow- 

 ering field of Early Red clover appear 

 very even Late Red Clover (Trifolium 

 pratense seroiinum) has the stems more 

 ])rane:hed. The branches are generally 4-6 

 in number and do not reacli full develop- 

 ment at the same time. They do not. attain 

 tlie same height as the main stem and as a 

 result the flowering heads are borne on 

 different levels. The various heads of a 

 typical Late Red clover plant are, there- 

 fore, during the blossoming and fruiting 

 periods, representing different stages of 

 development. Indeed, fully mature heads 

 with ripe seed and heads just beginning 

 to blossom may be found on the same plant. 



The most important difference between 

 Early and Late Red clover is, however, 

 their behaviour after cutting. The Early 

 Red clover ,has the faculty of producing 

 a vigorous second growth, for the reason 

 that after cutting it develops a second set 

 of quick-growing shoots. The Late Red 

 clover lacks the faculty of developing more 

 than one set of s^ioots in a season and as 

 a resull it produces a comparatively scant 

 aftermatli after cutting. On the other 

 hand, the yield from the first cutting is 

 very much heavier than t^e yield from the 

 first cutting of the Early Red clover. For 

 this reason the Late Red clover is espe- 

 cially adapted to northern sections where 

 on account of short seasons only one cut- 

 ting can normally be relied upon, the more 

 so because it is generally hardier and more 

 persistent than the Early Red clover. On 

 account of its inability to yield a heavy 

 second crop after cutting the Late Red 

 clover is often referred to as "single cut 

 clover" in Great Britain, "En-slaetsS Klov- 

 er" in Denmark, "einsohnittiger Rothklee" 

 in Cermany, all of w}iich names indicate 



that only one good hay crop may be ex- 

 pected in one .season.* 



Geographical Varieties. 



Red clover is very commonly- listed by 

 the trade and referred to in experimental 

 work under names which simply signify 

 the source of production of the seed. Thus 

 such names as Chilean, American, French, 

 Italian, Russian, Silesian, Swedish Red 

 clovers, etc., are commonly employed, the 

 result being that the misconception has 

 been gradually created t/iat the various 

 names represent more or less defined varie- 

 ties. This is, however, not necessarily the 

 case as will be shown in the following. 

 The use of geographical names such as the 

 ones mentioned is, however, of great prac- 

 tical advantage and many valuable results 

 have been secured from experiments with 

 such geographical ''varieties". One of 

 the most outstanding results is the finding 

 that seed of red clover produced at ^ome 

 generally compares very favourably, as far 

 as hay producing ability is concerned, with 

 imported seed and often, indeed, is vastly 

 superior. Manj^ years of experiments in 

 for instance Denmark {Nielsen 1, p. 184) ' 

 and Sweden {Witte 3, pp. 91-112) are quite 

 conclusive and have clearly brought out 

 the superior value of home-grown seed. 



As already intimated, however, the names 

 "American", "Russian", "Silesian", etc. 

 must not be taken to mean that red clover 

 lots so named represent more or less dis- 

 tinct varieties. On the contrary, especial- 

 ly in such European countries in which 

 red clover seed growing has been prac- 

 tised for a long time, a great number of 

 local varietiees have been more or less un- 

 consciously developed throug.ii a process 

 of natural selection. Such local varieties 



* It has ah-ead.v been pointed out that earli- 

 ness and lateness are in reality not the essen- 

 tial characteristics separating the Early fi-om 

 the Late Red clover. In fact, many varieties 

 of Late Red clover come into bloom compar- 

 atively early; such varieties might easily be 

 mistaken for Early Red clover were it not for 

 the fact that the branching of the stem and 

 the nature of the aftermath after cutting pro- 

 claim them to belong to the late • type (cfr. 

 Witte, 2, p. 60). For practical purposes the 

 various types are generally grouped together 

 as Early, Medium Late, and Late Red clovers 

 (cfr. Nielsen 1. p. 178). 



