DISEASES OF COTTON 279 



supervenes after some amount of normal growth has been made, 

 and sooner or later it is thrown off and normal growth resumed. 

 Meanwhile the form of the plant is strikingly changed and bearing 

 is almost entirely inhibited. 



The affection was widespread and long-continued in St. 

 Kitts and Nevis in June- July, 1914. It had been noticed in 

 previous years affecting fields here and there in St. Kitts, and 

 more regularly in particular localities in Nevis. It has also 

 occurred from time to time in Antigua, Montserrat, and St. 

 Vincent. An affection with symptoms the same in kind but 

 developed in somewhat different proportions has been trouble- 

 some in St. Croix. 



Description. 



The general character of the form of growth in curly leaf 

 disease is shown in Figs. 105-6. It is most noticeable towards 

 the upper extremity of the main shoot, but occurs also on the 

 laterals. The internodes of stems and branches, and usually the 

 leaf stalks as well, grow out to be abnormally long and slender. 

 The productive branches commonly have only two or three 

 nodes, which makes the number of possible flowers small. The 

 leaves from their earliest appearance are strongly crimped all 

 round their margin ; they are thin in substance, and pale green, 

 tending more or less to yellow, in colour. In some cases there is a 

 diffusion of still paler colour bordering the larger veins. In what 

 have seemed to be the more extreme cases examined numerous 

 small irregular holes occur torn in the body of the leaf and on 

 its edges. They arise from the inability of small brown spots 

 formed in the very young leaf to expand with the rest of the 

 tissue. 



The effect on bearing of the onset of this condition is profound. 

 There is a strong tendency for the flower buds to dry up, turn 

 black, and drop at a very early stage in their development ; 

 very many are lost when the bracteoles are but 2 or 3 mm. across, 

 others at various later stages. Some plants are rendered com- 

 pletely barren even of flowers in this way. Of the flower buds 

 which do succeed in developing many fail to open ; the outside 

 of the petals becomes slightly discoloured pink and takes on a 

 characteristic rather woolly appearance, and as the corolla 

 becomes mature the margins of the overlapping petals towards 

 the tip of the bud lack their normal firmness and cling together, 

 failing to expand. Complete withering of the petals follows. 

 Flowers examined in the first visible stages of the process have 

 been found to have the anthers already brown and withered. 

 The effect is possibly produced by gradual wilting of the petals 

 from the margin inwards, or it may be that they lack from the 

 first the consistency necessary for the expansion of the corolla. 



All experience has shown that so long as the curly-leaf con- 

 dition is prevalent the yield is exceedingly small. 



