306 



THE AGRICULTURAL NEWS 



September 28, 1912. 



influence upon rainfall, an increase of eight to fifteen 

 per cent, having been suggested. Results bearing the 

 opposite interpretation have been obtained in the 

 United States; some of them are presented in a paper^ 

 contained in a report to the United States House ot 

 Representatives on the influence of forests on climate 

 and floods. The conclusions in the paper indicate that 

 there is strong evidence for the inability of the removal 

 of forests to influence rainfall: it is that the latter 

 controls the rate of forest growth rather than than the 

 amount of forest cover influences the rainfall; the con- 

 ditions that aff"ect rainfall exist at such an altitude as 

 to prevent the way in which the land is covered locally 

 from possessing any influence. Actual, careful observa- 

 tions show that there has been no noticeable change in 

 the rainfall in the United States, during the time that 

 such observations have been possible. 



The advocates of the theory that forests induce 

 rainfall try to find confirmation of their views in the 

 resiilts that have been obtained by making simul- 

 taneous observations, at stations called parallel stations, 

 in a forest area and in the open surrounding country. 

 In nearly every place where these observations have 

 been carried out, a larger rainfall has been indi- 

 cated on the land under forest; so that it is held that 

 forests increase precipitation. If this conclusion could be 

 proved definitely to be correct, the circumstance would 

 be of the greatest importance, for it is easy to see that 

 the effect would extend beyond the forest area because 

 the wind would bear away the rain-carrying clouds 

 that had been formed. The opponents of the theorj' 

 do not agree that the observations have been inter- 

 preted correctly; experiments, they say, have demon- 

 strated that gauges situated in the forest register 

 a greater rainfall than those in the open because they 

 are sheltered from the wind. Attempts to allow 

 for this influence have been made, but the 

 matter is so uncertain that those who hold the 

 theory cannot be said to have made good their 

 case. The subject will be seen to possess pecu- 

 liar difficulty when it is realized that differences in 

 height above ground of the gauges as well as in 

 altitude above sea-level are easily capable of inducing 

 differences in the measure of the rainfall that are far 

 greater than those claimed for the influence of the 

 forest. 



It is thus evident that, at present, no definite 

 conclusion can be reached concerning the possible 



lAgricxiUuml News, Vol. TX, p. 248. 



influence of forests on rainfall. The review mentioned at 

 the commencement of this article sums up the matter 

 in the following way: 'Professor J. von Hann's opinion 

 on the subject, in the latest edition of his Handhuch 

 ihr Klimatologie is that the question cannot be 

 definitely answered at present, but that the effect, if 

 any, should be greater in the tropics than in higher 

 latitudes. Dr. G. T. Walker, of the Meteorological 

 Ofliae, Simla, is of a similar opinion. He states that 

 if forests have any influence at all on the rainfall, it 

 is probably not greater in India than five per cent.' 



The usefulness of forests in retarding the rate of 

 travel to the sea of water falling as rain, and in 

 improving conditions for plant growth, must not be 

 forgotten in any case: and this consideration alone 

 should prevent reckless deforestation and emphasize 

 the importance of the replacement of forest cover. 



SUGAR INDUSTRY. 



SOME WEST INDIAN SUGAR-CANES IN 



INDIA. 



The Annual Report of the Agricultural Stations in 

 Eastern Bengal and Assam for the year ending Jnne 30, 

 1911, shows that, among the sugar-canes grown at the Dacca 

 Agricultural Station during that time there were included 

 B.147, B.1753, F).376 and B.208. Among these it was 

 thought that one or two, together with Striped ^Mauritius, 

 would prove superior to the local cane on becoming accus- 

 tomed to the changed conditions. 



These canes were obtained from the Jorhat Agricultural 

 Station, and mention is made in the report that they were 

 under trial at this station; further, in describing their 

 behaviour there, it is stated that they all, except B.208, 

 showed resistance to red rot; it was decided however to 

 continue experimentation with this cane. As regards the 

 total yield of sugar from the canes that were grown success- 

 fully, Striped Mauritius attained the first place, followed by 

 B.376 and B.147. It is stated that a high yield with 

 a superior quality of juice are combined in these canes. The 

 varieties Striped Tana and Kheri also showed a high yield of 

 cane and juice, but the inferior quality of the latter caused 

 the yield of sugar per acre to be low. In another experi- 

 ment at this station, B.147, B.376 and Striped Mauritius 

 again showed a striking superiority as regards quality of 

 juice, the sucrose content and purity being high and the 

 glucose ratio low. B.208 is reported as having had to be 

 destroyed on account of disease in the previous year; it is 

 stated however, in the experiment under discussion, to have 

 given a juice of high quality in spite of the fact that it 

 continued to be very susceptible to attacks by red rot In 

 making general remarks concerning the sugar-canes under 

 trial at this station, the following statements occur: 'Two 

 of the Barbados varieties, viz. 15.147 and B.376, are exceed- 

 ingly promising. Although not such high yielders as 

 St! iped Mauritius, they gave juices of very high quality.' 



