16 BULLETIN 188, U. S. DEPARTMENT OF AGRICULTURE. 



THICK SEEDING AND THE SIZE OF PLANT STUMPS. 



Another advantage derived from seeding thicker than is cus- 

 tomary is the reduced size of the plant stumps. One of the objections 

 advanced against the growing of grain-sorghum crops, particularly 

 in the black lands of Texas, is the difficulty of preparing the land for 

 the succeeding crop. Where the plants grow very large the increased 

 size of the rooting system necesssCry to support a plant with several 

 stalks often causes soil to adhere to the roots, forming large masses 

 of mixed roots and soil. When the land is plowed, many of these 

 large clods, which are very difficult to turn under, are left on the 

 surface, greatly increasing the difficulty of properly preparing the 

 seed bed. Thicker seeding, by reducing the size of individual plants, 

 markedly lessens this difficulty. 



THICK SEEDING AND CROP STANDS. 



It is obvious that the best results can not be secured with milo 

 where the stand is irregular and spotted. Where relatively thin seed- 

 ing is practiced the chances of getting a good, uniform stand are 

 reduced. There are numerous conditions that operate to prevent 

 high germination of the seed and successful growth of the crop, and, 

 within reasonable limits, thick seeding is desirable, as it increases the 

 chances of securmg a good stand in spite of adverse conditions of soil 

 and climate. There is little danger of getting the milo plants too 

 close together in the row so long as the rate does not greatly exceed 

 5 pounds of seed per acre, the rate used in these experiments, with 

 rows 4 feet apart. As is shown in Table III, the highest yields were 

 obtained from the unthinned rows and the 2-inch spacing. In 1913 

 both these plats yielded at the rate of 46.4 bushels per acre. In 1914 

 the two plats so spaced yielded at the rate of 21.8 and 18.2, bushels, 

 respectivel}^. It seems certam that to secure satisfactory stands it is 

 desirable to plant at a rate at least as high as 5 pounds of seed per acre. 

 This would make a rather thick seeding if every seed produced a 

 plant, but this is seldom the case. The experiments carried on with 

 milo at San Antonio have shown that if the planter plates are so 

 arranged that only one seed is dropped where a plant is desired, such 

 a poor stand will generally result that the yields wiU be very materi- 

 ally decreased. In the experunent described above, with a seeding 

 rate of 5 pounds per acre, if every seed had produced a plant the 

 plants would have averaged about 1.5 inches apart, or 2,112 plants 

 to a 264-foot row. But, as is shown in Table III, there were onl}' 

 895 mature plants per row in the plat that was not thinned. 



THICK SEEDING AND MATURITY. 



It has already been shown that the closer spaced plants matured 

 earlier and more uniformly than those which were farther apart in 

 the row. As shown in Table V, the difference in earliness of maturity 



