GOSSYPIUM 



DISEASES 



THE COTTON PLANT 



Diseases. 



Chief Pests. 



Boll-worms. 



ing of Cotton, quoted in Ind. PI. and Gard., Aug. 12, 1905, 558 ; Clouston, Arti- 

 ficial Fert. for Cotton in C. Prov., in Agri. Journ Ind., 1907, ii., pt. ii., 116-22.] 

 V. DISEASES AND PESTS. While many writers make mention 

 of a " deterioration " of the cotton plant as having taken place in India, 

 remarkably little has been said of the actual diseases of the crop. Com- 

 pared with tea or coffee, Indian cotton can hardly be said to be affected 

 with disease further than failure of crops through unfavourable seasons. 

 Maxwell-Lefroy, Entomologist to the Government of India, has, however, 

 recently issued some useful and suggestive Notes on Cotton in Bihar 

 (Bull. Agri. Res. Inst. Pusa, Feb. 1904) in which he gives brief accounts 

 of some 14 pests met with in the cotton of that province, of which 

 3 are at present known in Bihar only and 11 are general to the cotton 

 tracts of India. He groups these pests under four sections as follows :- 



(a) Insects attacking the leaves and seen chiefly up to September. Under 

 this series he places the following : (1) hairy caterpillar ; (2) cotton- 

 leaf caterpillar ; (3) the cotton bud-worm ; (4) spotted boll-worm ; 

 (5) the white weevil ; and (6) the cotton leaf-hopper. (6) Insects in tl 

 stem: (7) the stem-borer and (8) the stem- weevil, (c) Insects in tl 

 boll: (9) the spotted boll-worm and (10) the pink boll-worm; (11) the 

 red cotton-bug ; and (12) the dusky cotton-bug, (d) Miscellaneous : (13) 

 the mealy bug; and (14) the large blister beetle. 



He then concludes with a recommendation to destroy systematicallj 

 all traces of the pests as they appear. In August and September 

 careful outlook should be kept for boll-worms, and all shoots or bol 

 showing signs of these should be destroyed. More recently Maxwell- 

 Lefroy has issued a paper entitled The Insect Pests of Cotton in India 

 (Agri. Journ. Ind., 1906, i., pt. i., 49-61 ; also Memoirs Dept. Agri. Ind., 

 Exotic Cottons. 1907, i., No. 2). This will be found to furnish fuller details of six of the 

 more important of the pests, while a further note (The Pests of Introduced 

 Cottons, 1907, ii., pt. iii., 283-5) furnishes a few particulars regarding 

 the pests to which exotic cottons are liable. 



A curious disease often present to a large extent in India is known to 

 the Natives as gosai or tulsi (the Ocimum-like). The former name (" the 

 ascetic") denotes the non-flowering and fruiting of badly affected plants, 

 and the latter their colour and general appearance seen at a distance. 

 The leaves, at first large and exceptionally vigorous, ultimately curl up 

 and become small, very numerous, and are then seen to be coated with a 

 woolly formation known as Erinosis a growth at first supposed to be of 

 fungal origin but now definitely ascertained to be caused by a mite (Phy- 

 toptas yossi/pi). This perplexing pest is often very prevalent in 

 Gujarat, as much as 5 to 10 per cent, of the bushes being thereby 

 rendered more or less non-productive. It might be dealt with similarly 

 to the treatment of Erinosis on the vine or other plants, namely by 

 sulphur or kerosene emulsion. [C/. G. F. Atkinson, Diseases, and L. 0. 

 Howard, Pests, in Dabney, The Cotton Plant, 1896, 279-350.] 



Resistant. 0. F. Cook has written a highly interesting and most sug- 

 gestive report on Weevil-resisting Adaptations of the Cotton Plant (U.S. 

 Dept. Agri. Bull., 1906, No. 88). The form specially investigated is the 

 kekchi cotton of Guatemala. This he describes as a dwarf annual short- 

 season variety with numerous features which, in the absenceof sufncientnum- 

 bers of keleps (the so-called Guatemalan ant that kills the weevil), affords 

 material assistance in protecting the crop against the ravages of that pest. 



610 



The Cotton Mite. 



"Weevil- 

 resisting 

 Adapta- 

 tions. 



