INSTITUTE AND COLLEGE, PUSA, FOR 1911-12. 27 



9. De-cobbing Maize Plants. — Several Agricultural 

 Journals* have contained notes on the effect of removing- the 

 cobs from maize plants prior to fertilisation by the pollen, 

 this process being said to result in an accumulation of sugar 

 in the stem. Experiments were made by Mr. A. C. Dobbs, 

 Assistant Inspector General of Agriculture, during last 

 monsoon period in order to test the effect of the process 

 and to ascertain whether it would prove itself a useful one. 

 Analyses of the plants showed that an increase of sugar 

 (sucrose) did occur; in one case the cane sugar rose from 

 2 per cent, to 9 per cent., the percentage referring to the 

 weight of stem, but the process was not considered on the 

 whole to be an economical one. 



10. Ex'perimenial Error in Sampling Sugar-cane. — It 

 will be readily appreciated that when a sample of cane is 

 taken from a field which is supposed to represent the whole, 

 an error is involved, and the examination of the sample will 

 not show the average composition of the whole but will 

 depart from the true value to a greater or less degree. It 

 is also obvious that not only is a knowledge of the magni- 

 tude of this error of importance, but also that it is very 

 desirable to know how to take a sample of sugar-cane in 

 order to free the result of such errors as far as possible. 



Some tests were made in 1910 and again this year with 

 the sugar-cane crop which were designed to elucidate the 

 subject, but it will be necessary to carry out a third series 

 of tests during the coming season in order to arrive at 

 definite conclusions. In illustration it may be mentioned 

 that if a sample of 3 or 6 canes is taken from a field the 

 " probable error " is about 1 per cent, to 2 per cent, in the 

 sucrose determination. By taking more and more canes in 

 the " sample " the error becomes naturally smaller, but even 

 if one -fourth of the crop of a n)-acre plot be crushed, an 

 appreciable error still remains, and one- fourth of such a 

 crop is a large quantity of cane. It is the size of the 

 smallest necessary sample to be taken in order to secure an 



* Agricultural Journal of the Union of South Africa, Vol. I, No. 4, p. 540. 

 Agricultural News, Vol. X, No. 234, p. 115. 



