276 



Journal of Agricultural Research 



Vol. XVII, No. 6 



temperatures at which the corn remains after picking, are sufficient to 

 cause marked differences in the rate of deterioration. "Whether the 

 main thesis be accepted or not, the data presented are sufficient to 

 indicate that a close relation exists between the quality of sweetcom 

 and the temperature at which it is handled. 



LOSS IN SUGAR AFTER PICKING 



That green corn deteriorates rapidly after picking is a matter of 

 common observation, and that an important factor in this deterioration 

 is the loss in sugar has been pointed out by Straughn, Appleman, and 

 others. Straughn, working with Stowell's Evergreen in Maryland, re- 

 ports (/J, p. 6g) that in freshly pulled samples 4.59 to 4.74 per cent 

 total sugars were found. On standing 24 hours at room temperature, 

 unhusked, about one-third of the sugars disappeared; after this the loss 

 continued until the sugars reached 1.80 per cent. More recently, Apple- 

 man and Arthur (2, Table HI), working with the same variety stored 

 at accurately controlled temperatures, report that at 20° C. more than 

 25 per cent of the total sugar was lost during the first 24 hours after 

 picking, and that at 30° C. more than 50 per cent of the total sugar was 

 lost in the same period. Analyses of Golden Bantam com made at 

 Lewiston, Me., during 191 8 showed rapid loss in sugars in stored corn. 

 The ears were split lengthwise and a sample from one half analyzed 

 immediately, while the other half was stored. 



TablS I. — Total sugars in Golden Bantam corn in edible condition, calculated as per- 

 centage of invert sugar on original wet weight, Lewiston, Me} 



Ear No. 



Approxi- 

 mate 

 number 

 of hours 

 stored at 

 20° C. 



6. 



9- 



10 



24 

 20 

 48 

 48 



I The method used was essentially that of Bryan, Given, and Straughn as modified by Hassclbring 

 and Hawkins. The total sugars were calculated as invert sugar by the methods of Mimson and Walker. 

 Bryan, A. H., GrvEN, A., and Straughn, M. N. extraction of grains and cattle foods for the 

 DETERMINATION OF SUGARS ... U. S. Dept. Agr. Bur. Chem. Circ. 71, 14 p., 1911; Hasselbring, Heinrich, 

 and Hawkins, Lon A. physiolooicai. changes in sweet potatoes during storage. In Jour. Agr. 

 Research, v. 3, no. 4, p. 335, 1915; Wiley, H. W., ed. offici.vl and provisional methods of analysis ... 

 U. S. Dept. Agr. Bur. Chem. Bui. 107 (rev.), p. 241, 1908. 



RELATION OF TEMPERATURE TO RATE OF SUGAR LOSS 



The recently published careful researches of Appleman and Arthur (2) 

 explain the earlier and somewhat conflicting statements of Straughn, 

 Church, and Wiley (ij, 14) and leave no doubt that the rate of loss of 

 sugar in stored sweetcorn is directly dependent on temperature. Apple- 



