12 CIRCULAR XO. 130, BUREAU OF PLANT INDUSTRY. 



of the possibilities that lie in this direction. Tlie behavior of a tropi- 

 cal plant when placed for the first time under new conditions may be 

 altogether abnormal, as in the case of some of the new tj^pes of cotton 

 introduced in recent years from tropical America. But by acclima- 

 tization and selection it has been possible in a few years to obtain 

 early productive varieties from stocks that grew into large sterile 

 bushes when first introduced.' 



The luxuriant growth of weeds lends another tropical aspect to 

 agriculture in Louisiana. The weeds not only take full advantage 

 of the opportunities of perennial growth, but are ready to spring 

 up at any time that the land is left idle. One crop needs to follow 

 another in quick succession in order to keep control of the weeds 

 and at the same time keep down the expenses of cultivation. To 

 insure the prompt succession of crops it is often necessary to plant 

 two toirether or to sow one before the other is taken off. Thus, there 

 may be another important advantage in shortening the growing sea- 

 son of cotton so that it can be raised in rotation with winter crops. 



Othei^ possibilities lie in the use of tree crops to assist in weed 

 control or to give favorable conditions for other crops that thrive 

 better with partial protection from the sun, We are accustomed to 

 think of agriculture as an art that must be practiced out in the sun 

 in the open field, but in tropical and subtropical countries many crops 

 are grown as subcultures under the protection of trees. Thus, in 

 some districts of southern Italy much of the agriculture is of this 

 intensive character. Labor may be reduced by such methods, but 

 intensive care and skill are required to combine crops successfully. 

 Even cattle raising, which seems to have excellent prospects in Lou- 

 isiana, must be done on a more intensive basis, as in the Tropics, for 

 rich lands are soon covered with woody growth unless measures are 

 taken to protect the grass or to maintain a rotation with other crops. 

 Some of the tropical grasses might prove valuable in relation to the 

 problem of weed control as well as for pasture or fodder. 



In some important respects Louisiana must be considered as the 

 most tropical part of the United States, as shown by the conjunction 

 of three distinctively tropical crops — sugar, cotton, and rice. It is 

 true that Florida and Texas extend farther south, but they do not 

 afford to the same extent the tropical combination of rich alluvial 

 soil and abundant moisture. The lands along the lower Mississippi 

 also afford unusually favorable opportunities for developing methods 

 of frost protection, especially with crops that could be saved by flood- 

 ing from the river. Tree crops or perennial^ that will not survice 

 frost are excluded, of course, but many annual crops are grown in 

 different parts of the tropical and subtropical world, and some of 



1 Cook, O. F. IlPi-pflity nnd cotton hrrodina;. U. S. Department of .Agriculture. Bureau 

 of Plant UKlustr.v, Bulletin 2r>0, 113 p., Ill tig., 6 pi.. 1013. 

 [Cir. 130] 



