NICOTIANA 



Diseases 



THE TOBACCO PLANT 



Mildew. 



Erysiphe cichoracearum, DC. Butler (Proc. Board Agri., Pusa, 1906, 

 82) remarks that it is probably the grey mildew which attacks the leaves 

 in the Azamgarh district of the United Provinces, known as kapti. The 

 same authority states that no remedy has been proved to be efficacious. 

 " The application of sulphur either in form of ' flowers of sulphur ' dusted 

 on, or as potassium sulphide sprayed on, is efficacious in checking many 

 mildews, but might interfere with the curing processes and be difficult 

 to remove from the leaves." At Pusa a leaf-spot disease, due to Cerco- 

 spora Rficiborskii, Sacc. & Syd., is said to be common, but its effects are 

 not very serious. 



Maxwell-Lefroy enumerates the common insect pests of the tobacco 

 plant in India under the following five heads : 



1. Grasshoppers attacking newly transplanted seedlings. Clean 

 culture and thorough tillage are the best preventatives. The only direct 

 remedy is to dip the seedlings in standard lead arseniate mixture as they 

 are planted. 



2. Surface caterpillars, i.e. those living in the soil, hiding by day and 

 emerging by night to feed on young plants. Search reveals their burrows, 

 where they can be found and destroyed. The alternative methods are 

 to poison the young plants or to put down baits of poisoned chaff. 



3. The stem caterpillar, attacking young plants. These live in the stem 

 and cause gall-like swellings. Plants up to a foot high are principally 

 attacked. The cultivator's method of cutting open the gall by a longi- 

 tudinal incision is probably the best. 



4. Leaf-eating caterpillars. When these appear on young plants, 

 spraying the leaves with poison is a sound remedy. On old plants, the 

 caterpillars must be picked off by the hand. 



5. In Tirhut a cricket (probably the common burrowing Brachytrt/jtes 

 achatimis, Stoll.) is reported to injure the leaves by coming out at 

 night and eating holes in them. Where they are not abundant they can 

 be dug out, which is best done during August and September. 



In seriously infested localities the most satisfactory treatment is to grow 

 a crop such as lucerne and thoroughly poison it, thus poisoning off the 

 crickets. -In the United States of America flocks of turkeys are reared 

 on the tobacco farms with a view to exterminating the caterpillars that 

 do so much injury to the crop. [Cf. Proc. Board Agri., Pusa, 1906, 

 88, 94, 110-1, 113-4 ; Delacroix, Sur une Maladie du Tabac, le 

 " Chancre " ou " Anthracnose," in Comptes Rendus, 1903, cxxxvii., 454 ; 

 also La Rouille blanche du Tabac, etc., 1905, cxl., 678 ; Maxwell-Lefroy, 

 Mem. Dept. Agri. Ind., 1907, i., No. 2, 113-252.] 



MANUFACTURE. 



Withering. The leaves are considered mature when the texture 

 becomes granulated and of a dark green colour with yellowish blotches. 

 The lower leaves ripen first, the others in succession upwards. According 

 to one system the leaves are cut off singly or in pairs (with a connecting 

 portion of the stem), or the stem with its entire series of leaves is severed 

 Withering, at once. The first stage in manufacturing is the withering of the leaf. 

 This is usually accomplished by cutting down the plants or leaves and 

 spreading these out on the ground, thus exposing them to the action of the 

 sun for a few minutes or hours. They are then carried to the drying- 

 house. But if rain falls during the withering, the plants or leaves must as 

 rapidly as possible be carried to the drying-house and the reaping dis- 



804 



Pests. 



Grasshoppers. 



Caterpillars. 



Stem-borers. 



Leaf-borers. 

 Cricket. 



Caterpillars. 



Manufac- 

 ture. 



Eeaping. 



