FIELD CROPS 455 



wheat of this character before it is allowed to cure out in the shock 

 for a few days ; otherwise sufficient heat may be evolved, even in the 

 stack, to injure the grain, in which case "stack-burnt" wheat will 

 result. 



Cutting the grain seems to act as a sort of check upon this 

 biological action, and it appears to remain in a dormant state until 

 the assembling of the grain in large bulk brings on a condition, 

 favorable to activity. When the grain is stacked the straw permits 

 to a limited extent the circulation of air through the stack, and 

 this circulation affords a means of conducting away considerable 

 of the heat generated in stacked grain. 



Heat-Damaged or Bin-Burnt Wheat. If wheat with a rather 

 high moisture content is placed, before going through the sweat, in 

 a large bulk in a bin there is very little chance for circulation of 

 air, and any heat generated by biological action is retained in the 

 grain until finally the temperature oecomes so high as to cause 

 other chemical changes within the kernels; the result is what is 

 commonly known to the grain trade as heat-damaged or "bin-burnt" 

 wheat. This injury may extend simply into the branny coats and 

 produce slightly heat-damaged or "bran-burnt" wheat, or it may ex- 

 tend throughout the endosperm and produce badly heat-damaged or 

 "bin-burnt" kernels. Wheat in this last condition is practically 

 unfit for flour-making purposes. 



Effect of Sweating in Stack. In order to make a preliminary 

 test regarding the validity of the practically unanimous opinion 

 among farmers and millers that wheat which had been bleached in 

 the shock was improved in color and test weight per bushel upon 

 being stacked and allowed to go through the sweat in the stack, and 

 also to discover what effect this sweating process in the stack would 

 have upon the market grade and the milling and baking value of 

 the wheat, arrangements were made during the harvest of 1909 to 

 secure from a 12-acre field of Fife wheat near Fargo, N. Dak., a 

 load of bundles taken from the shock after they had been exposed to 

 at least two heavy rains. This load was thrashed and the wheat 

 stored in a small elevator bin. The remainder of the field was 

 stacked and after standing in the stack six weeks was thrashed. 

 Fifty bushels of the stacked wheat, taken from the same portion of 

 the field as the before-mentioned load of shocked bundles, was 

 placed in another small bin in the same elevator for comparison 

 with the shock-thrashed wheat. 



The shock-thrashed sample as it came direct from the thrash- 

 ing machine contained 14.8 per cent of moisture, and the test 

 weight per bushel was 55.5 pounds. The grain felt damp and 

 tough and would scarcely have been considered in safe condition for 

 shipment to market. 



Added Advantages Derived from Stacking Wheat. The farm- 

 er who properly stacks his wheat secures it against further loss from 

 exposure to weather, while the one who allows his grain to stand 

 in the shock from three to six weeks, waiting for the thrasher, run? 



