8 CIRCULAR 863, U. S. DEPARTMENT OF AGRICULTURE 



where. In east-central Alabama it thrives on a stiff "brick clay" 

 on which cultivated crops often fail. 



While, in general, sericea will thrive on poor, eroded soils, it 

 should be pointed out here that some soils in the Piedmont have 

 been so badly eroded that not even sericea thrives. The result is 

 doubtless related to the degree of erosion and the character of 

 the subsoil in the exposed horizon. Sericea is a "poor-land crop" 

 only in the sense that it can be established successfully on thin 

 eroded and depleted croplands, provided that its seedbed prepara- 

 tion, moderate fertilization and seeding requirements are met. It 

 is entirely practical to establish good stands of sericea on land 

 where it would be inadvisable to plant "good land crops" like 

 alfalfa, for example. 



Applications of phosphate and potash are necessary for sus- 

 tained good production of sericea for hay, seed and/or pasturage. . 

 If essential plant nutrient minerals are lacking, yields will be 

 low and the forage unpalatable. 



Sericea will grow under irrigation in the West; however, it 

 does not compete with alfalfa in quantity and quality of hay 

 produced. It is not a competitor of alfalfa. Its place is on the 

 sour, eroded soils of low fertility level throughout the southeastern 

 quarter of the United States. 



CULTURE 



Germination of Hard Seed 



Sericea seed as harvested is in the hull. While the hull is but a 

 delicate membrane that readily absorbs water, the seed coat is 

 hard and in most of the seeds is impermeable to water. This 

 results in a low percentage of germination. 



Many germination tests have been made both in the seed labora- 

 tory of the Department and in soil or sand in the greenhouse. 

 The results have varied widely. In some cases the germination 

 of the unhulled seed has been as low as 2.5 percent, with 88 to 

 91.5 percent remaining hard. In others up to 72 percent of the 

 unhulled seed have germinated with 19.5 percent remaining hard. 

 In most cases, the range of germination of unscarified seed has 

 been between 10 and 20 percent. 



Selection work was carried out by the Bureau of Plant Industry 

 over several years with the hope that the descendants of certain 

 individual plants that in 1928 produced a high percentage of 

 quickly germinable unhulled seed might inherit this quality. No 

 progress was made, however, as descendants of plants producing 

 in one year a high percentage of quickly germinable unhulled seed 

 were, in later years, no better than the average. No explanation 

 can be offered today for this variation in results. Possibly climatic 

 conditions when the seed is ripening may have an influence, but 

 no evidence has been found to sustain this supposition. The varia- 

 tion in results from year to year is shown by the record of five 

 individual plants (table 1). 



