14 CIRCULAR 863, U. S. DEPARTMENT OF AGRICULTURE 



SERICEA STANDS 

 Volunteer Stands 



A thin stand may thicken later by two methods: (1) The exist- 

 ing plants may produce an increasing number of stems in suc- 

 cessive years, thus piouucing a better cover, or (2) seedlings may 

 become established irom tallen seed. When the first crop has 

 been allowed to seed, whether this is harvested or not, a certain 

 amount of seed is sure to shatter. Under favorable conditions 

 many of these seeds will produce seedlings and a thickening of 

 the old stand may result. 



On good land a volunteer stand is more or less certain, pro- 

 vided competition for light is eliminated. It can be eliminated 

 by cutting the first growth of the older plants for hay. On 

 some areas these older plants have been cut for hay several 

 times in a season in order to give the young seedlings plenty of 

 light. While sericea seedlings endure some shade, the shade from 

 a full growth of established plants, even when in rows 3 feet apart, 

 is so dense that the seedlings are smothered. On medium to 

 good land it is well to allow one crop of the old plants to seed 

 and to cut them once or twice the next season for hay. Full 

 stands have been noted where the original seeding was made on 

 good soil in rows 3 feet apart. The first crop was allowed to 

 seed and three years later there was a thick stand. 



As it is doubtful whether a volunteer stand can be as expected 

 on soils of low productivity, every effort should be made to get 

 a satisfactory stand from the first seeding. Fields have been 

 noted on very poor soil where, even though the old plants had 

 seeded abundantly and had not been cut, practically no repro- 

 duction had taken place. It is inferred that in such cases the 

 seedlings that did start could not endure the competition of the 

 older plants. Such competition appears to be chiefly for moisture. 



Number of Plants to a Stand 



The number of plants per unit area may be readily determined 

 during the seeding year, but it is difficult or impossible to do this 

 in a well-established stand. The only way to make an exact de- 

 termination of the number of plants in an old stand is by digging. 

 This was done by the Bureau of Plant Industry in an experiment 

 designed to study the effect of cutting on sericea. Plants were 

 dug in 1936 from a number of square-foot areas in a 3- and 4- 

 year-old stands on clay soil at Arlington Experiment Farm and 

 on sandy soil at Beltsville. On the clay soil the number of roots 

 varied from 21 to 32.6 per square foot, or 914,760 and 1,420,056 

 per acre, respectively. On the sandy soil the numbers were 15.5 

 and 21.7 per square foot, or 675,180 and 945,252 per acre. In 

 both cases the stands were good. The roots varied in size, since 

 some were obviously from 1 -year-old volunteer plants while most 

 of them were from well-established plants. The dry weight of 

 the roots ranged from 2,305 to 2,907 pounds per acre on the 

 sandy soil and from 3,692 to 5,168 pounds on the clay soil. 



