SUGAR-CANE 



SUGAR-CANE 



603 



wise good, are rendered worthless by the attacks of 

 these pests, so that resistance to them may deter- 

 mine the value of the cane for seed purposes almost 

 as much as the production of vigorous buds. 



The handling of cane is necessarily rough, and 

 prominent buds are often bruised or broken during 

 the handling. From this it follows that canes with 

 low flat buds are to be preferred to those with 

 round and prominent buds. This is especially the 

 case where the cane has to be flumed for long dis- 

 tances, as the effect of the water is to soften the 

 buds and they are then more easily rubbed off as 

 they pass along the flume. 



To prepare cane for seed purposes, it is cut into 

 sections, each having one or more buds which it is 

 intended shall germinate and start a new stool. 

 While the new plant is establishing itself, it grows 

 at the expense of the sucrose and other matters 

 stored up in the cutting. It is important, there- 

 fore, that this store of food 'shall be preserved for 

 the use of the plantlet. If the cane is brittle, it is 

 likely to shatter when cut for seed ; that is to say, 

 the stroke of the knife causes each piece to split at 

 the end in the manner familiar to everybody in chips 

 of wood produced by the axe. These cracks afford an 

 opportunity for various organisms to enter the cut- 

 ting after it is planted, and cause it to decay much 

 more rapidly than it otherwise would. For this 

 reason a cane that is brittle is one that is of less 

 value as seed than one that is not. For this reason, 

 also, the tops of stalks are more valuable than 

 other parts because they are more succulent, and 

 therefore less liable to shatter. To avoid shat- 

 tering, or even cutting, it is the custom of some 

 planters to use whole cane for seed. 



Leaf. — The microscopic structure and the chem- 

 ical composition of the leaves determine the 

 amount of resistance they will offer to the attacks 

 of the various fungi that are peculiar to this part 

 of the plant. This subject is one that has not yet 

 been sufiiciently studied to determine the precise 

 nature of the various factors, but it is known to 

 growers that certain varieties are more susceptible 

 to leaf diseases than others. For example, the yellow 

 varieties are more susceptible to many leaf diseases 

 than the red and green varieties. It is now known 

 that the various structures indicated vary to a 

 considerable extent in the different varieties, and 

 it is reasonable to suppose that some of these vari- 

 ations are correlated to resistance to disease. The 

 thickness and the chemical composition of the cell 

 walls will determine the resistance of the internal 

 cells to the dissolving effect of parasitic fungi. So, 

 too, the thickness of the cuticle and its chemical 

 composition will determine the resistance to such 

 fungi as dissolve their way through the cuticle. No 

 doubt many of the fungi that enter the cane-leaf 

 do so by way of the stomata. It is known that these 

 vary in number and structure in the various varie- 

 ties and thus offer various degrees of ease with 

 which the parasites may enter. Again, it is through 

 the stomata that a number of these parasites make 

 their exit for fructification. Here, again, the num- 

 ber and size of the openings determine the degree 

 of resistance to the formation of fructifications. 



Resistance to drought is largely a function of 

 the leaves, for it is through the opening and closing 

 of the stomatic openings that transpiration is con- 

 trolled. A variety that promptly and effectually 

 closes its stomata under dry conditions is one that, 

 other things being equal, resists drought best. 



At certain periods of its growth, it is customary 

 in some localities to strip the stalk of its lower 

 leaves in order to facilitate the ripening processes. 

 The attachment of the leaf is a factor of impor- 

 tance in this connection. In some varieties the leaf 

 comes away with ease, and leaves a beneficent scar, 

 while in other varieties when the leaf is removed 

 the connection is such that there is a tendency to 

 tear away some of the tissue of the stalk, and thus 

 leave wounds which may be entered by wound- 

 parasites that work injury to the cane in reducing 

 the sucrose. The attachment of the leaves is also 

 related to disease in another way. In some varieties 

 the sheath of the leaf is so related to the stalk as 

 to resist the entrance of both insect and fungous 

 parasites, while other varieties admit of the early 

 entrance of mois- 

 ture and injurious 

 parasites. 



It is the large- 

 leaved varieties 

 that, as a rule, 

 are the most pro- 

 lific, although, un- 

 fortunately, also 

 generally the 

 most subject to 

 disease. It ap- 

 pears that the 

 rapid growth re- 

 sulting in the pro- 

 duction of large 

 leaves is more or 

 less incompatible 

 with the produc- 

 tion of disease- 

 resistant tissues. 



Flower. — Of re- 

 cent years, the 

 structure of the 

 flower of the cane 

 plant has assumed 

 great importance 

 because of the at- 

 tempts to produce 

 new canes by 

 crossing known 

 varieties. Thpse 

 attempts and the resulting studies have disclosed 

 a number of very interesting facts with regard to 

 the anatomy and physiology of the blossom. Until 

 recent years it was thought that the blossoms of the 

 cane plant were infertile and that such a thing as 

 a cane seedling was an impossibility. In the latter 

 eighties, however, seedling canes were reared, and 

 from that time much progress has been made in the 

 art of producing new varieties. In the following 

 countries and in the following order, approximately, 

 the subject has received attention: Java, Australia, 



Fig. 829. Sugai-cane. Stripping and 

 cutting. 



