CULTURAL DIRECTIONS 



395 



performed at the first weeding, when 8 or lo plants are 

 allowed to the linear foot of row, Init in verj^ good soils 

 and when large bulbs are desired, the plants should 

 stand about 2 inches apart. Special hand weeders (Fig- 

 ure 7) are in common use. Both weeding and thinning 

 should be avoided as much as possible by the proper 

 preparation of the soil and the adjustment of drills. 

 Figure 92 shows a well-managed onion field on Long 

 Island. 



FIG. 92. FIELD OF ONIONS ON LONG ISLAND 



539. Irrigation. — In many sections of the West and the 

 Southwest onions cannot be grown without irrigation, 

 the ground being too dry to supply the moisture neces- 

 sary. All of the Bermuda onions of the Southwest are 

 grown under irrigation. The land is flooded before 

 planting and afterwards at intervals of a week or^ 10 

 days until the bulbs are full sized, when water is with- 

 held to induce ripening. An increasing number of grow- 

 ers in various parts of the country are employing the 

 overhead system of irrigation, which is ideal when ap- 



