ii6 DISEASES OF CROP-PLANTS 



but the limits within which this may be done and especially those 

 within which it may be done profitably are, in respect of many 

 tropical crops, rather strictly drawn. This is the more pro- 

 nounced because neither management nor labour are as yet 

 capable of going beyond somewhat crude agricultural practices. 

 The relevance of these reflections to the consideration of certain 

 types of plant diseases will appear in the following pages. 



To make clearer to outside readers the conditions and crops 

 of the various islands the following summary is given. The 

 islands are arranged in geographical order from north to south. 



St. Kitts-Nevis. 



The cultivated land in St. Kitts covers a broad belt of usually 

 gentle slopes stretching from the sides of the central range 

 (highest elevation 3,700 feet) to the coast, and is mostly occupied 

 by estates of the old sugar-plantation size. Sugar-cane is 

 universally grown, with cotton as a catch crop. The steeper 

 slopes for some distance above this belt are occupied in places 

 by gardens in which the usual West Indian provisions — sweet 

 potatoes, yams, bananas, corn, cassava, groundnuts, etc. — are 

 raised. For the greater part of the necessary supplies of this 

 nature St. Kitts depends on the adjacent island of Nevis. The 

 upper slopes of the mountains are covered with rain-forest or 

 tree-fern. 



The soil is light and deep, and particularly easy to work. 

 The average rainfall on the cultivated areas is some 40-50 inches, 

 according to position. 



The only serious affection of sugar-cane is root disease, which 

 occasionally causes local reductions of crop. The light soil is 

 quickly affected by drought, and lends itself to depletion of 

 fertility when not systematically manured. The prevalence 

 of either condition allows the development of root disease. 



The same quality of the soil particularly favours cotton- 

 growing by greatly reducing liability to shedding, and the 

 average yield is high. The plants grow to a large size and the 

 consequent humidity in wet years induces some losses from boll 

 diseases. 



The cultivated land in Nevis is arranged around its central 

 mountain (3,500 feet) in much the same way as that of St. Kitts 

 around its central range. Many of the old sugar estates have 

 been divided into peasant holdings. Provisions are raised in 

 quantity for local consumption and export to St. Kitts. The 

 staple crops are sugar-cane and cotton. There is a rather 

 large coconut estate near Charlestown, and vanilla is grown 

 in some quantity near the edge of the upland forest at Maddens. 

 The average rainfall at Charlestown is about 50 inches ; its 

 seasonal distribution is erratic. 



The soil is rather heavy, and cotton is consequently more 

 subject to losses from shedding than in St. Kitts. Sugar-cane 



