164 PERIODICITY IN TllE GROWTfi OF SUGARCANE 



and Samalkota have been included. Eighty-nine unit observations on these 

 varieties form the basis of the present paper. 



The varieties dealt with are the following : — Saretha, Chin, Khari, Ghynia, 

 Pansahi, Baroukha (of Sabour and not of the United Provinces, a member of 

 the Nargori group of canes), and Mango. All of these have been examined 

 at the Cane-breeding Station, at Taliparamba and Samalkota, and such of 

 them as were found growing at the Coimbatore Ceutral Farm, Nagpur, Sabour, 

 Pusa, Partabgarh, Shahjahanpur, and Aligarb. The observations at the latter 

 place are less complete, in that only six canes were measured and these at an 

 early stage of growth, but they are included because they indicate certain 

 well-marked characters which have still to be checked. A study of the agri- 

 cultural conditions and the curves of growths obtained have led us to divide 

 these places into three regions: (1) The Coimbatore Central Farm, Talijiar- 

 amba, Samalkota and Nagpur represent wet land, continuously irrigated from 

 tanks ; (2) The Cane-breeding Station, consisting of slightly saline garden land, 

 dry land irrigated from wells ; (3) Gangetic alluvium. The latter region has 

 of necsssity been less fully studied than the rest, and in many cases the record 

 is very incomplete. There are great variations in the curves obtained from 

 these northern places, but it has not been found possible, with the data avail- 

 able, to subdivide the tract. Suffice it to say that there appear to be as great 

 differences in growth in North India as in South India, and that the rate of 

 growth appears to be greater in Aligarh, Shahjahanpur, and perhaps Sabour, 

 than at Pusa and Partabgarh. The last named gives, in almost all cases, a 

 less vigorous growth than in any other place of those observed. The Cane- 

 breeding Station, with its handicap of well-irrigation and intractable soil 

 with slight salinity, shows curves much more similar to those obtained in 

 North India than any of the wet land places, thus justifying its selection for 

 the work of raising seedlings for North India. It has been already stated 

 that our record is to a certain extent incomplete. This was of necessity the 

 case, in that the work of accurate measurements has gradually extended, and 

 the object of the present paper was not at first held in view. But it is held 

 that this will not invalidate the method, which can be much more easily 

 employed when the opportunity occurs of putting down the same varieties 

 in each place. This incompleteness has, in the present instance, entailed a 

 great deal of labour, in that there are a number of points which need safe- 

 guarding, lest conclusions are arrived at on insufficient data. A statement 

 is appended of the observations on which this paper is based, showing the 

 number of units obtained for each variety at each place, and some of the 

 pitfalls are detailed below with the means adopted of avoiding them. 



