IRRIGATION OF FIELD CROPS. 233 



has been carefully attended to. If the soil is excep- 

 tionally dry and warm, however, irrigation may occur 

 every ten days after a month from the transplanting, 

 but no moisture to the root is needed after the plants 

 are topped. In arid America the leaves need artificial 

 sprinkling to produce salable fiber. The ordinary 

 fruit tree sprayers may be used and the plants given 

 two or three light showers in the early evening after 

 the plants begin to ripen. This will supply the defi- 

 ciency in air moisture and cause the fibers to thicken 

 and become more solid. 



Potatoes. — Here is something that requires scien- 

 tific irrigation. The ground intended for an irrigated 

 crop should be a smooth piece, having sufficient slope 

 to make the water run freely between the rows. It 

 should be plowed eight inches deep, or more, and then 

 harrowed and dragged until the soil is firm through- 

 out and thoroughly pulverized on the surface. Lay 

 off the ground in rows three and one-half feet apart 

 with a corn marker, or a small shovel which will 

 make a .shallow furrow, the rows running the same 

 way the ground slopes, if it is not too steep. A slope 

 of seven to ten feet to the mile gives good results. 

 The distance apart in the rows depends upon the 

 variety. If the Early Ohio, which grows the smallest 

 vines of any variety , be used I would advise planting 

 ten inches apart in the row. If the Peach Blow, 

 which grows the largest vines of any variety, be used, 

 I would advise a distance of twenty-one inches apart. 

 The rows should be from three feet to three feet six 

 inches apart. The closer you have the rows, and yet 

 be able to work with horses conveniently, the better, 



