46 TROPICAL AGRICULTURE 



ture is always hot and where the seasons show the least varia- 

 tion. Under the latter conditions the growth is constant and 

 the cane never comes to so complete a maturity as occurs on 

 the borders of the Tropics where also the greatest purity of 

 cane juice is obtained. 



Throughout the Tropics there is an almost universal sys- 

 tem of nomenclature for the crops of cane as well as for many 

 other tropical crops. The first crop from seed planting is called 

 the plant crop, and subsequent crops obtained without replant- 

 ing are called rattoon crops. In Java, most of the sugar cane 

 crop is plant cane. In Louisiana, the crop is made up of plant 

 cane and first rattoons. In Hawaii, the common practice is 

 to harvest a plant crop and two rattoon crops. In Mauritius, 

 three rattoon crops are taken, and in Cuba and the West In- 

 dies it is customary to continue without replanting up to the 

 fifth rattoon crop or in certain fields as long as 25 years or 

 more. The number of crops taken without replanting is, of 

 course, not determined by theoretical considerations of the 

 possibility of the successful growth of cane after being cut, 

 but strictly for economic reasons. In some localities the third 

 rattoon crop is so light and the yield of sugar so low that it 

 is more profitable to plow and replant than to allow the plant 

 to remain for the production of a third rattoon crop. In a 

 few localities in Hawaii, for reasons which are not at all ap- 

 parent, sugar cane has continued to yield excellent crops 

 without replanting for a period of 25 years. This would not 

 be considered an unusual performance in Cuba and the West 

 Indies. 



The optimum quantity of water for cane, either as rainfall 

 or irrigation water, depends to a large extent on the physics 

 of the soil, the rate of evaporation, and the farming system 

 according to which the soil is handled. The rate of evapora- 

 tion, as is well known, varies greatly in different localities and 

 this naturally has much to do with the amount of water re- 

 quired for the growth of cane. The optimum quantity of 



