HARVESTING AND STORAGE 481 



to the condition of the crop and the manner in which the chap. 

 sheller is operated and fed. • 



There are so many good shellers offered, that it is im- 

 possible to say which is the best, without giving each a 

 thorough trial. 



454. Importance of Drying-out the Grain. — Where the 

 crop is grown for grain only, it is advisable to leave it in the 

 field until it is thoroughly dry. The ear continues to ac- 

 cumulate nutriment for a considerable time after the stalk 

 has been cut. The value of the grain in the European 

 market depends largely on its dryness ; for export it should 

 not contain more than 12 per cent moisture. To secure this 

 degree of dryness without injury to the grain, it should be 

 allowed to dry out on the stalk. If the ears are " snapped " 

 (i.e. broken from the stalk) before the grain is dry, the grain 

 shrinks and is more or less damaged. Cutting and shocking 

 the stalks, if done at the right stage of growth, does not 

 interfere with the proper drying out and conditioning of the 

 grain. 



455. Loss of Weight in Drying. — A considerable loss of 

 weight is found to take place in maize, left on the cob between 

 harvest and the middle of November. The lost moisture is 

 not replaced in spring by humidity of the atmosphere, even 

 when good rains occur after the middle of October. Tests 

 made at the Botanical Experiment Station, Pretoria, in 1908, 

 showed that the loss of moisture averaged 21 per cent in seven 

 months, but ran as high as 35 per cent. In the United States 

 it averages about I 5 per cent. South African maize is usually 

 5 per cent drier than the American, which added to their 15 

 per cent loss gives an average of about 20 per cent. Weighings 

 were made on I April, at the beginning of the dry season, and 

 again at the end, 17 November. The loss in drying on thirty 

 ears of yellow dent, averaged 2173 per cent of the original 

 weight and varied from -42 per cent to 31-2 per cent. Numer- 

 ous tests have been made in the United States and have 

 ranged from 3 per cent to an extreme of 30 per cent, ac- 

 cording to degree of dryness at time of storing in the crib, 

 in four and a half months. 



The amount of loss depends largely on the condition of 

 the ears at the time that they are first weighed, and varies 



^1 



