164 THE DEVELOPMENT OF RAW COTTON 



valuable, but they necessitate daily observations, or 

 alternate days at the least, if daily observations are ab- 

 solutely impossible. They are more valu- 

 er ermg a ^ e because they are not subject to so many 

 sources of error as the boiling records, and 

 therefore give more accurate comparisons from plot to 

 plot, especially as regards the early stages of growth. 

 After the flower has opened, it may be prevented from 

 ripening into a boll through shedding caused by water 

 shortage or excess of water, or by weather; or through 

 the attacks of insect pests or fungi. The boiling record 

 thus merely shows how the crop was produced, but the 

 flowering record helps to explain the why and wherefore. 

 Flowering records cannot be taken satisfactorily on odd 

 days, or even at regular intervals, because the flowers do 

 not accumulate as the bolls do, and also because the rate 

 of flowering varies very greatly from day to day, owing 

 to previous variations in the growth-rate of the flowering 

 branches. In spite of these disadvantages, if flowering 

 records can possibly be obtained, they are well worth the 

 trouble, on account of the insight they give into the way 

 in which the yield was formed. It is not always realized 

 that the number of flowers opening is the 



Flowers and main Determinant of the final yield of a 

 the Yield. J 



cotton-field ; the yield may be less than the 



flowering would indicate (Fig. 10), but it cannot be more. 

 The results can be plotted similarly into curves, on the 

 same scale as the boiling records, per plant or per area ; the 

 difference between the two curves shows the loss on any 

 day or in any week from shedding and from insects, and 



