TOBACCO IN ROTATION 473 



$286.86. The Connecticut and Florida tobacco is largely 

 grown under the shade of muslin screens and the cost of pro- 

 duction is high, so that the net returns, while greater than 

 in the other states, are not so large as might at first appear. 



645. Rotation. A Virginia rotation for dark tobacco is: 

 First year, tobacco; second year, wheat; third and fourth 

 years, mixed grasses and clover; fifth year, corn; sixth year, 

 cowpeas. A Pennsylvania rotation is: First year, wheat; 

 second year, grass; third year, tobacco. The rotation may 

 be extended a year by growing corn after wheat. In Ken- 

 tucky tobacco is sometimes grown for two years in succes- 

 sion after a crop of blue grass. In Wisconsin it is advo- 

 cated that on low and prairie soils, well-supplied with humus 

 and nitrogen, and even on sandy and clay loams a rotation 

 need not be employed till depreciation occurs. 



646. Insects and Diseases. Tobacco is not subject to 

 injury from many insect pests or diseases. The most fre- 

 quent pest is the horn worm, or tobacco worm, which feeds 

 on the leaves. This may be killed by applying from J^ to 

 1 pound of dry Paris green to the acre, mixing the poison 

 with about twenty times its bulk of flour and applying it 

 to the plants with a bellows. If too much poison is used, 

 it will burn the leaves. The smaller worms are killed by the 

 Paris green, but it does not affect the larger ones. These 

 must be removed by hand picking. Few diseases attack 

 the plant in the field. Damping-off, or bed rot, and other 

 fungous diseases sometimes occur in the plant bed, but these 

 are ordinarily controlled by burning the bed before seeding, 

 sowing only the best seed, and giving proper attention to 

 ventilation and watering. 



647. Selection of Seed. A few of the choicest plants may 

 be allowed to produce seed. As half a dozen will produce 

 enough seed for several acres, there is plenty of opportunity 

 for the selection of only the very best plants. These ought 

 to be uniform and typical of the variety or type which is 



