OTHER FARM CROPS 595 



nematodes. This kind of plant food enables the plant to throw out 

 neAV roots faster than the nematodes can destroy the old ones. 



When produced for wrapper purposes the Sumatra variety of 

 tobacco is usually grown under shade. The purpose of the shade is 

 to protect the crop from insects and other dangers and by reason of 

 reducing the light to secure a thin leaf. The effect of the shade is 

 also shown in influencing the humidity of the atmosphere and the 

 temperature. The plants under shade show a much more rapid 

 growth than the outside tobacco, and the leaves are finer, very thin 

 and elastic, and with very small veins. Such characteristics as these 

 in wrapper tobacco are desired by manufacturers. 



Where no cover crop is grown during the whiter the land 

 should be plowed frequently and kept thoroughly stirred. This de- 

 stroys many of the nematodes, and in that way greatly reduces the 

 damage due to these insects the following year. This constant cul- 

 tivation also prevents, to some extent, the depredations of the thrips ; 

 it prevents the growth of grass and weeds, which serve as host plants 

 for this insect. 



The preparation of the soil for Sumatra tobacco must be thor- 

 ough and complete. The soil should be thoroughly pulverized by 

 successive plowing and harrowing, and reduced to a fine condition 

 before transplanting. Deep plowing and subsoiling causes a reten- 

 tion of moisture in the soil if the season is too dry, and at the same 

 time affords the best opportunity for proper drainage if there is an 

 excess of rainfall during the growing season. The disk plow and. 

 disk harrow have been used very successfully in the preparation of 

 tobacco soils, particularly where the content of clay is comparatively 

 small. 



When transplanting the young plants from the seed bed to the 

 field, it is desirable to make a selection of the best and most vigor- 

 ous plants in the seed bed. At this early stage of growth the most 

 vigorous plants, having the largest and best-shaped leaves, can be 

 very easily distinguished by the grower and selected for the field. 

 The ordinary distance for Sumatra under cloth is 3 feet 3 inches 

 apart for rows and 12 inches apart in the row. Under slat shades 

 the distance between the plants in the row is usually increased to 

 about 14 inches. 



Before removing the young plants from the seed bed, the bed 

 should be thoroughly watered and the plants taken out with all pos- 

 sible care. In setting the plants in the field care should be taken to 

 avoid bending and doubling the roots, and the necessary applica- 

 tion of water should not be overlooked. It is often found beneficial, 

 just before transplanting, to water the soil where the plant is to be 

 set, and to water again shortly after transplanting. 



The cultivation of the crop should include the removal of all 

 weeds from the field, particularly during the early stages of growth, 

 and a thorough cultivation of the soil at frequent intervals in order 

 to keep a loose mulch on the surface of the soil: It is usually the 

 custom to hoe the young plants twice and to use some form of culti- 

 vator at least once a week during the remainder of the season until 



