191 1.] Tobacco Growing for Insecticidal Purposes. 381 



be allowed to heat until just before the beds are made. It 

 should be about nine inches to a foot deep, or at the rate of 

 about one ton of manure per 6 feet by 4 feet sash. The glass- 

 covered frame should then be placed on the top of the 

 manure without any delay, and the heap covered with about 

 two inches of finely prepared soil in which to sow the tobacco 

 seed. 



Tobacco seed is extremely small and consequently very 

 difficult to sow thinly and evenly. The best way is to mix 

 the seed with a large quantity of ashes so as to increase the 

 bulk. It can then be sown more thickly, and there is the 

 additional advantage that the colour of the ashes shows up 

 against the soil, so that the sower can see when any part of 

 the seed bed is left unsown. 



The quantity of seed sown was one-thirtieth of an ounce 

 to each sash, but this was found to be too much, and one- 

 fortieth of an ounce of seed would be quite sufficient. The 

 sowing was done on March 23rd. 



Planting Out, Soil and Manuring. — The young plants 

 may be put out in the open as soon as all danger of frost 

 is over, about the end of May. The most suitable soil for the 

 production of nicotine, so far as the experiments have shown 

 at present, is a moderately heavy rich loam with liberal 

 manuring. A good foundation in the form of dung in the 

 autumn will be required, followed by a good dressing of 

 artificials in the spring before planting out. Nitrogenous 

 manures especially seem to encourage the formation of 

 nicotine, so that two or three small dressings of nitrate of 

 soda after the plants have become established will be found 

 useful. 



The soil must be thoroughly well worked and reduced to a 

 fine tilth before planting out. The rows should then be 

 marked out with an empty drill 3 feet or 2\ feet apart, and 

 the plants dibbled in after the manner of cabbages at 

 distances of 2 feet or ij feet in the rows. Foreign experi- 

 ments have shown that the closer the plants are put together 

 the higher becomes the yield but the lower the percentage of 

 nicotine. The experiments last year failed to show any 



difference in nicotine content, whilst the close-planted plot 



(3 feet by 1 \ feet) gave the heaviest crop. 



