20 CIRCULAR NO. 123, BUREAU OF PLANT INDUSTRY. 



ciently wide range of conditions to enable us to establish any definite 

 degree of temperature at wliich germination begins to suffer, but 

 the observations made indicate very clearly that it is not safe to 

 plant any seed which has been subjected to even the slightest heat- 

 ing and fermentation, and that the planting value of the seed may 

 be entirely destroyed by a sweating and curing-out process, which 

 does not injure the lint to any perceptible extent. The practice of 

 saving seed for planting from late pickings is due, no doubt, to the 

 greater tendency of early pickings to heat. 



When this particular pile of cotton was forked over to bin B, 

 on the morning when the maximum temperature of 111° F. was 

 discovered, it was thoroughly mixed and no portion of the pile 

 again developed a temperature of as much as 90° F. This would 

 indicate that the heatmg which had reduced germination to about 

 10 per cent was only a transient condition incident to the curing of 

 the pile. 



CONCLUSIONS. 



As a result of this season's observations the conclusion is reached 

 that similar data must be secured on earlier pickings and on cotton 

 picked more promptly after rains, as well as upon cotton stored in 

 larger and smaller piles and in both moist and dry climates, before 

 any definite rules can be laid down concerning temperatures at 

 which injury to seed or fiber takes place. An interesting question 

 arises as to the effect on the milling and feeding value of seed which 

 has been so heated as to prevent germination. Experiments and 

 observations on a number of these points are planned for the coming 

 season. The facts here recorded are believed to be of value as 

 establishing certain known points of damage to germination, and 

 also as showing the perfect safety with which considerable bodies 

 of mature seed cotton can be stored if care is taken to have the 

 cotton free from exterior moisture when stored. 



[Cir. 123] 



