160 CHAPTER IX 



(•2) Better seed production, especially if combined with 

 good hay qualities. 



(3) Greater drought resistance. 



(4) Greater cold resistance. 



(5) Varieties that possess ability to produce seed under 

 humid conditions, so that adapted strains may gradually be 

 developed. 



(6) Better pasture varieties, especially such as have root- 

 stocks, so as to withstand pasturing without injury. 



(7) Disease resistance. 



The characters enumerated are all possessed in varying 

 degrees by different varieties. 



Since the plants cross-pollinate naturally a large propor- 

 tion of lucerne plants are heterozygote. To propagate, selected 

 plants should be enclosed in insect-proof capes to prevent cross- 

 pollination, or increases should be made by cuttings. Either 

 method should be used until sufficient seed has been obtained 

 to sow in an isolated fair-sized plot, which should be situated 

 at some distance from other fields, as crossing is usually accom- 

 plished by bees of short-tongued species, e.g., MegacJiile and 

 Andrena. 



Cage plants must be hand-tripped. 



Hybridising lucerne is a relatively easy operation,'* and 

 Oliver has secured some interesting hybrids, chiefly between 

 falcata and saliva.^ 



Seed Production. — During recent years the production of 

 seed in the Union has increased markedly, particularly in the 

 Cape Province, where the Oudtshoorn District has developed 

 this feature to an important extent. South African seed is 

 sold at a reasonable figure, and with the cleaning methods 

 recently introduced, is of very good quality. 



Unlike the South Western States, the plants set seed 

 freely in the Union. The first growth is cut for hay and the 

 subsequent growth allowed to mature seed — 400 to 800 pounds 

 per acre is considered a good yield of seed. For seed produc- 

 tion a thinner sowing is necessary, and less water should be 

 given. 



Pests and Diseases. — Lucerne is, relatively speaking, 

 very free of those causing much damage. 



Lucerne Caterpillar {Colias elecira). — This is a yellow 

 butterfly which, in the larval stage, a smooth green caterpillar, 

 may do considerable damage. If badly threatened, the crop 



