36 CHAPTER IV 



but others presented wide variation. This observation led Harrison to the 

 conclusion that cross-fertilization was unnecessary for the object of the work, 

 and therefore this method has been little used by him. 



2. It was soon found that, although the Kara-Kar-awa and Brekeret 

 were prolific parents, there was little probability that any of their progeny 

 would become valuable as sugar producers. This observation was also found 

 to be true of seedlings of these varieties, so that eventually Harrison reduced 

 his parents mainly to D 625, Bourbon, White Transparent, and Red Ribbon. 



3. Of these four varieties it is observed : 



" The following generalizations can be made of certain of the economic char- 

 acteristics of the progeny of the parent varieties : 



D 625. Vigorous seedlings, juice generally richer than that of the parent, 

 flower and seed sparsely ; ratoon well and resist drought. 



Bourbon. Proportion of selected seedlings low ; the seedlings suffer very badly 

 in drought ; liable to fungoid disease ; ratoon only moderately ; some flower and 

 seed freely, others sparsely. 



White Transparent. Seedlings generally rich in juice ; grow well as plants, 

 but are poor as ratoons and rapidly deteriorate ; flower and seed very freely. 



Red Ribbon. Juice generally rich ; flower sparsely as a rule ; good drought- 

 resisters. 



These generalizations are based upon our lengthy experience with large num- 

 bers of seedling varieties. Our accumulated evidence as to the several economic 

 characters of the different seedling varieties remains to be analysed." 



5. The method of selection of the seedlings is as follows : 



" First selection of parent varieties for seed producers ; 



Second selection of the more vigorous of the seedlings obtained from them for 

 field propagation ; 



Third selection of the varieties growing under field conditions by the cultural 

 characteristics ; 



Fourth selection from these selected sorts by their analytical characters ; 



Fifth selection. The third and fourth methods are repeated with plants raised 

 from the tops of the varieties selected under the fourth selection, and this is done 

 repeatedly during the cultivation of them from plants to second and third ratoons. 

 As the method of cultivation in British Guiana renders it necessary for canes to 

 have good ratooning powers to be of service as sugar producers, we lay more stress 

 on the selection from ratoons than from plants ; 



Sixth selection. The varieties which have been selected are next grown on 

 plots of about i /2O acre, side by side and under identical conditions of cultivation 

 and manuring. Their peculiarities are carefully watched, and out of batches of 

 forty or so selected for this trial, probably not more than a dozen will be retained 

 in cultivation as third or fourth ratoons ; 



Seventh selection. During the course of the fifth and sixth selections several 

 of the varieties finally retained in cultivation will have been selected by planters 

 for large-scale cultivation. These and others selected by ourselves are next exam- 

 ined by means of manurial experiments. Plots of about i /2 acre are divided into 

 smaller plots, and upon these the varieties are raised under different systems .of 

 manuring. Some of the plots of every kind are manured with phosphates, and 

 perhaps potash, others are not. Some of each are grown without nitrogenous 

 manure, others with increasing quantities of nitrogen applied in the manure. 

 It has been found that the mean results of a kind under the different manurings 

 apparently offer the most reliable figures as to comparative value we can obtain in 

 small scale experiments." 



The canes obtained by Harrison and his colleagues that are or have 

 been prominent are described below. 



D 74. A descendant of White Transparent. Stalk Pale green, erect, 

 stout, medium length of joint. Leaf Broad, light green. Arrows profusely, 

 matures early. 



