ALFALFA HYBRIDIZATION 



Attempt to Improve Plant by Breeding for Better Seed Production and Grazing 



Qualities Success in Crossing with the Black Medick Segregation in the 



Offspring Importance of Insects in Pollinating Flowers. 



William South worth 

 Department of Plant Breeding, Ontario Agricultural College, Guelph, Canada. 



FEW forage crops are better known 

 than Medicago saliva L. — alfalfa, 

 lucenic or i)ur]jlc medick. It is, 

 l)erha])s. partly because it is so 

 well known that so little has been done 

 to improve it by scientific breedin*^. 



Its chief value to farmers on the 

 North American continent lies in its 

 capacity to produce large crops of 

 nutritious forage, cut to feed green or 

 made into hay. The croj) is occasionally 

 grazed by cattle and sheep, but most 

 ])ractieal men agree in the ojDinion fre- 

 quently exjjressed that our present 

 commercial strains are not well adapted 

 for grazing: if the crop is so treated it 

 rai)idly loses root and quickly dies out. 



Another serious defect in our existing 

 strains of alfalfa, very marked in some 

 districts, is the lack of capacity to pro- 

 duce seed freely. As one of the great 

 essentials of a farm croj) is j^ower to 

 profluce an al)undant suj^i^ly of seed, it 

 will be readily vmderstood that the shy 

 seeding habit of alfalfa in some districts 

 is a serious drawback to its general 

 utility. 



Thus, despite the immense economic 

 value of our jjrescnt-day strains of 

 alfalfa, there arc at least two lines in 

 which their im])rovement or modifica- 

 tion might be undertaken with advan- 

 tage, viz: 



(1). To obtain a strain having the 

 cajjacity to set seed more freely under a 

 greater variety of soil, climatic, and 

 other environmental conditions. 



(2). To oV)tain a variety which will 

 be better ada[)ted for grazing. 



The first ])art of the problem might 

 be solved l)y simple selection. Unfor- 

 tunately, all the types which seem to 

 offer jjos.sibilities for grazing appear to 

 be below th : average in the capacity to 



448 



produce seed. Hence it seems unlikely 

 that a complete solution of the problem 

 could be expected by following a course 

 of selection no matter how perfectly the 

 s\'stem might be conducted; conse- 

 quently it was decided to test what 

 success could be accomplished by cross- 

 ing the alfalfa with another suitable 

 plant in the same genus. The plant 

 which seemed to fulfil most of the con- 

 ditions required is the common yellow 

 trefoil, otherwise known as black 

 medick [Medicago lupulina L.). 



THE BLACK MEDICK. 



This plant may be described as having 

 slender stems, mostly prostrate, fre- 

 quently lying fiat on the surface ot the 

 land; it produces an abundance of fine 

 leaves and these together with the soft 

 and succulent stems yield good grazing 

 but not good hay. 



In the United States and in Canada 

 it is usually looked upon as a weed, but 

 in Great Britain and some other 

 European countries it is sown largely 

 for use as a grazing crop and is con- 

 sidered to be well adapted to sheep 

 ]:)asturcs on dry, uj^land, chalky and 

 limestone soils. Black medick is only a 

 temix)rary plant, not lasting more than 

 two years, but is a ])rolillc producer of 

 seed. 



As compared with black medick 

 alfalfa may, in general, be called up- 

 right in gro\vth, stems fairly stout, bear- 

 ing many leaves; it is well adapted for 

 cutting for hay and yields heavy crops 

 of rich fodder but is not suited for 

 grazing. It has a very decj) root system, 

 is strictly ])erennial, but under some 

 conditions does not seed very freely. 



The general form of the alfalfa flower 

 and the manner in which pollination is 



