12 BULLETIN 291, U. S. DEPARTMENT OF AGRICULTURE. 



YIELDS OF EARLY AND LATE TYPES OF SORGO UNDER CONDITIONS OF DROUGHT. 



There is no doubt that the later and larger growing varieties of 

 sorgo will produce a greater tonnage of forage in a favorable season 

 than the smaller forms, but in a dry season the earlier kinds are likely 

 to produce the larger crop. The advantage of an early variety was 

 shown at the Belle Fourche Experiment Farm in 1913, where two 

 types of sorgo were grown under different conditions of soil moisture. 

 The two sorgos compared were Red Amber, which is late in maturing 

 in this locality, and Dakota Amber, a very early variety. They were 

 grown under two conditions of soil moisture: (1) On plats which 

 produced millet the previous season and were entirely exhausted of 

 any stored moisture, and (2) on plats which were fallow in 1912 and 

 were in excellent moisture condition at the time of planting. The 

 total dry matter produced is shown in Table VI. 



Table VI. — Forage production of early and late types of sorgo under conditions of limited 

 and of ample soil moisture supply at Newell, S. Dak., in 1913. 



Variety. 



Red Amber (late maturing) 



Dakota Amber (early maturing) No. 341-10-4. 



Air-dry forage per acre 

 (pounds). 



Series A ; 

 moisture 

 limited. 



Series B; 



moisture 



ample. 



1,500 7.600 



2.150 4,500 



The plats which had been in millet (series A) suffered considerably 

 from lack of moisture and were harvested August 25, 79 days after 

 planting, the plants having by that time reached the limit of their 

 growth. The plats which had been fallowed (series B) contained 

 available moisture throughout the season and were harvested Septem- 

 ber 11, 96 days after planting. At this time the seeds of Dakota 

 Amber were fully mature, while the seeds of Red Amber were in the 

 early dough stage. Under conditions of drought the early strain 

 produced 43 per cent more air-dry forage, but where both wore 

 enabled to approach maturity under favorable conditions of moisture 

 the later strain produced the larger crop by 69 per cent. 



COMPARATIVE YIELDS OF SORGO, MILLET, AND OTHER ANNUAL 

 FORAGE CROPS LN THE CENTRAL AND NORTHERN GREAT PLAINS. 



The farmer will desire to know which of the two crops here dis- 

 cussed is the more profitable under dry-land conditions and also how 

 they compare in value with other annual forage crops which are 

 suitable for growing in the Great Plains. Variety tests conducted 

 in the Great Plains region by the Office of Forage-Crop Investigations 

 of the Bureau of Plant Industrv 1 have shown that the saccharine 



i Vinall, n. N. Annual forage crops for the dry lands. In Tour. Amer. Boc. Agron., v. 5, no. 3, p. 176- 

 181. 1913. 



