194 STUDIES IN INDIAN SUGARCANE SEEDLINGS 



Male sterility is judged by closed anthers, for, wlien these aie open., the 

 pollen is well formed, while it is only immature and filled with starch when 

 the anthers are closed. The percentage of open anthers is determined under 

 the lens in all the arrows dealt with, this being simpler than, the former method 

 of testing male fertility, by iodine, for the presence of starch. 



Flowering at Coimbatore occurs from October to December, although 

 later cases are often met with. A study of the best method to induce flowering 

 has resulted in the discovery that it depends chiefly on the time of planting. 

 The best planting time for obtaining arrows is about November, but extends 

 in some cases to as late as March-April. As the former is not the best time 

 for cane j)lanting o]\ the station, "' arrowing plots " have been, instituted, 

 l)laii.ted in November, and these have been attended with marked success. 

 Certain years, however, appear to be better for arrowing than, others. For 

 protection against foreign pollen the arrows are covered by fin,e muslin bags 

 outside bamboo or iron cages, much as is done in Java work. Caging must 

 be done before emergence of the inflorescense from its sheath, as some flowers 

 have been seen to open their anthers before protrusion,. When, the analysis 

 shows few open anthers, cross pollination, can. be attempted but. when, many 

 anthers are open, it is probable that most of the flowers are self fertilized, 

 and crossing has not proved successful. It seems tliat there is some ground 

 for assuming prepotency of the pollen in cave flowers, alth()Ugh this has not 

 been definitely settled. The season of flowering at Coimbatore is in. the heart 

 of the north-east monsoon, a period of much lain and strong winds, an.d this 

 adds to the difficulties, as the slightest perman.ent bend in the delicate floAver- 

 ing stalk seems to ren.(ler the ovules infertile. 



The. sources from which cane arrows have been obtaiiutd aiv. various. 

 They are abundant in the ryots' fields locally, have been, obtained from Banga- 

 lore, where flowering is excellent and also from Taliparamba on the west 

 coast and Samalkota on the east. By various means, an increasing number 

 of canes have been induced to flower on. the station itself. A very large 

 number of North Indian, canes have now been collected there, and numv of 

 these have been made to flower, some for the first time. The farm is thus 

 gradually becoming independent, and this adds a great deal to the efiiciency 

 of control as to parentage. Pollen is now being sent from a distance bv post 

 by the use of small gelatine caj)sules, and a])pears to retain its vitality longer 

 than expected. Sugarcane seed has also been tested and has proved to keep 

 good for a luimber of months. 



The t-Beatmeut of tho collected arrows is now stereotyped. They arc 

 chopped-up and spread over an intimate mixtuie of finely jiowdereti horse 



