4 DEPARTMENT OF AGRICULTURE BULS. 1201-1225 



Page 

 Department Bulletin No. 1204. — Dusting Cotton from Airplanes: 



First use of airplanes in applying insecticides 1 



Dust hopper construction 2 



The hand-crank hopper 3 



The air-suction hopper 5 



The Dayton hopper 7 



Field dusting studies 9 



Location and plan 9 



Leaf worm conditions 12 



Behavior of the dust in the air 12 



Influence of various air conditions 18 



Adhesion of poison to plants 21 



Manipulation of planes 21 



Flying methods used 22 



Rate of dust delivery • 26 



Directing plane operation 29 



Leafworm control operations 29 



Tests of various insecticides 31 



Different calcium arsenates 31 



Lead arsenate _ 32 



Paris green 32 



Observations on boll weevil control 33 



General considerations of airplane dusting 33 



Acreage dusted per hour 34 



Advantage of airplanes after rainfall 34 



Suitability of terrain 35 



Control or dust spread 36 



Suggestions for future investigations 37 



Characteristics of airplanes used 38 



Cost of operation i 39 



Conclusions 40 



Department Bulletin No. 1205. — Dusting and Spraying Peach 

 Trees After Harvest for Control of the Plum Curculio: 



Results of experiments at Fort Valley, Ga., in 1921 2 



Jarring before dusting 2 



Dusting in 1921 4 



Jarring after dusting 4 



Results of insectary work in 1921 7 



Other field and insectary observations in 1921 10 



Results of experiments at Fort Valley, Ga., in 1922 10 



Jarring before treatment 11 



Spraying and dusting in 1922 11 



Jarring after treatment 12 



Results of insectary work in 1922 14 



General summary 17 



Recommendations 18 



Department Bulletin No. 1206. — Marketing Southern-Grown 

 Sweet Potatoes: 



The sweet-potato industry 1 



Storage facilities 4 



Disposition of the southern crop 5 



Southern commercial varieties 7 



Car-lot movement and distribution 8 



Grading 13 



Packing 20 



Containers 22 



Loading and shipping methods 26 



Outlets and methods of sale 34 



Advertising 38 



Cooperative marketing 39 



Federal services in marketing 41 



Recommendations 45 



Publications relating to the sweet potato 47 



