the insecticides when the largest 

 roots are ^ to 1 inch in diameter. 

 Use 75 pounds of dust per acre. 



For shallow-rooted varieties, ap- 

 ply dust as soon as the roots start to 

 enlarge, then apply again 2 weeks 

 later (or about the time the soil 

 starts cracking because of root 

 growth). Apply 40 pounds of dust 

 per acre each time. 



Apply the dust along the row in 

 a strip 6 to 8 inches wide. Direct 

 the dust to the surface of the soil 

 under the foliage at the base of the 

 plants. 



Do not apply dieldrin within 21 

 days or heptachlor within 30 days 

 before harvest. 

 Harvest 



Examine each sweetpotato as you 

 dig it. Feed all those that are wee- 

 vil infested to livestock, or destroy 

 them immediately. 



After Harvest 



Care of Field. — Immediately after 

 harvest, collect and destroy all crop 

 residue — stems, roots, and cull 

 sweetpotatoes. Some of the unin- 

 fested residue may be saved to use 

 as bait for adult beetles. Vines 

 treated with dieldrin or heptachlor 

 should not be fed to dairy animals 

 or animals being finished for 

 slaughter. 



Place the bait material at inter- 

 vals around the edges of the field, 

 then apply dieldrin or heptachlor 

 dust to the ground in a circle sur- 

 rounding the bait. Do not apply 

 dust to the bait. In about 30 days 

 collect and destroy the bait. 



Plow the field once or twice dur- 

 ing the winter. Collect and destrov 

 all sweetpotato scrap material that 

 you unearth. 



Destroy any volunteer sweetpotato 

 plants as soon as they appear. If 

 a new crop in the field makes this 

 undesirable, apply dieldrin or hep- 

 tachlor dust to the soil around the 

 stems of the volunteer plants. 



Dusting Harvested Potatoes. — 

 Sweetpotatoes that are to be stored 

 in quantity may be treated with 

 DDT dust as a means of preventing 

 or reducing spread of the weevil, but 

 this should be done only if the sweet- 

 potatoes will be washed thoroughly 

 before they are eaten or offered for 

 sale. 



Just before storing the potatoes, 

 dust each crate thoroughly with 

 about 0.8 ounce of 10-percent DDT 

 dust. 



DDT will kill the newly developed 

 adults before they can lay eggs. It 

 will not kill larvae within the 

 potatoes. 



QUARANTINES 



All the southern sweetpotato- 

 producing States maintain quaran- 

 tines to prevent the spread of the 

 sweetpotato weevil. Spread may 

 occur when sweetpotato plants, 

 seed, or table potatoes are moved 

 from infested to noninfested areas. 



States that maintain quarantines 

 permit the entry of sweetpotatoes 

 from infested areas only after pre- 

 scribed requirements are met. 



STATE PROGRAMS 



Most of the States infested with 

 the sweetpotato weevil are engaged 

 in programs to control it. 



As a part of these programs, non- 

 planting zones Y 2 to 1 mile wide are 



