39 



cane are found in countries where the normal rainfall is constant 

 throughout the year, except possibly during the milling season after 

 the cane has reached maturity and where irrigation is unnecessary. 

 As the rainfall varies very widely in the different cane-producing 

 countries of the world no particular standard as to the amount of rain 

 required can be given. Doctor Stubbs states that in Louisiana a rainfall 

 of 1,52-t millimeters (60 inches) gives the best results, especially 

 when as much as 1,143 millimeters (45 inches) of this falls during 

 the growing season of the cane. The rainfall of the Hawaiian Islands is 

 very irregular and varies in sections where cane is successfully grown, 

 from 500 to 10,000 millimeters (20 to 400 inches). 



Rev. Miguel Saderra Maso, of the Philippine Weather Bureau, has 

 compiled the following table showing the average annual, and mean 

 monthly rainfall at the principal observation stations in the Islands 

 (see page opposite). 



As can be seen the average annual rainfall in most parts of the 

 Philippines is sufficient to produce a good crop of cane without irriga- 

 tion, but there is a distinct dry spell in many provinces during the 

 tirst three or four months of the year. Maxwell ^ gives the amount 

 of rainfall required to mature a crop of sugar cane growing for a period 

 of seventeen months as 2,540 millimeters (100 inches), an average of 

 about 150 millimeters (6 inches) per month or a total of 1,800 milli- 

 mefprs (T2 inches) per annum. He also says that the best results 

 are obtained when the young cane receives only about 52 millimeters 

 (2 inches) per month, while the cane in full vigor should receive 

 monthly about 305 millimeters (12 inches) per month. The latter 

 figures are amply borne out by extensive observations on irrigation in 

 the Hawaiian Islands where there is a tendency to apply too much 

 water to the young cane. 



The total rainfall of the best sugar districts in the Philippines is 

 slightly in excess of the amount required according to j\Iaxwell and 

 is almost ideal in distribution, which permits of dry-season planting 

 and cultivation from January to May with abundant rainfall for the 

 main growing period from June to December. The Government irriga- 

 tion projects planned for the Philippines will have only a limited use 

 in sugar growing though irrigation will prove very valuable to sugar 

 growers in those sections in which the average monthly rainfall of the 

 dry season is below 50 millimeters. 



Sugar-cane soils. — The principal characteristic of good sugar soil 

 is its ability to retain a high percentage of moisture. Dr. W. C. Stubbs 

 says that the be^t soil for sugar cane should be capable of holding 25 

 per cent of its weight of moisture. This quality is only found in the 



* Bulletin No. 90, Office of Experiment Stations, U. S. Department of Agri- 

 culture. 



