THE PLANT 



47 



Jeading, through this conception of a flowering scaffolding, 

 is that the ultimate yield of the plant has been partly 

 determined some two and a half months before it appears 

 as ripe cotton bolls. 



Various investigations have shown that, as most 



Daijy June I6*. h - June 30* h July 20 th Au^ gth Au^t29*. h Sep* 8*. h 



Fro. 10. PLANT-DEVELOPMENT CURVES AND THEIR USE ra FORECASTING 



Actual experimental data taken in a crop of Dcmains Afifi at 

 Giza in 1913. 



Daily records were taken in scattered groups of plants to obtain the daily 

 rate of growth of the main stem (c/. Fig. 9, p. 44), the number of flowers 

 opening, and number of bolls ripening (cf. Fig. 15, p. 110) each day. 

 These have been smoothed for convenience to five-day means (see p. 197). 



From left to right are G, the growth-curve; F, the flowering curve; B, the 

 boiling curve, the area enclosed by this last having teen shaded with 

 vertical lines to emphasize its importance as representing the actual 

 final yield. 



If G is moved forward for seventy-four days, and F for fifty-one days, they 

 closely resemble the early part of B. 



Thus, the ripening of the first picking, day by day, can be foretold two and 

 a half months in advance. 



Later pickings can also be forecasted by similar means; they follow the 

 flowering curve, with deviations due to shedding of the flowers. 



growers will concede willingly, the number of bolls 

 ripened depends on the number of flowers which open 

 (Fig. 10). A certain proportion of these flowers are shed 

 by the plant, the average amount under Egyptian con- 



