32 



CIRCULAR 862, U. S. DEPARTMENT OF AGRICULTURE 



Table 12. — Response of crop plants to DDT in soil in the field, Beltsville, 



Md., 191+8 and 19 U9 



[DDT applied to soil in June 1947] 



Year, crop, and 

 variety 



Harvested part 



Yield per plot in response to 

 pounds of DDT per acre shown 



1948 

 Cereals : 

 Barley: 



Sunrise 



Wong 



Oats: 



Fulghum 



Oklahoma 



Lee 



Rye: 



Abruzzi: 



Plants not ma- 

 ture 



Plants mature, 



dry 



Rosen 



Wheat: 



Kay 



Trumbull 



Beans: 

 Lima: 



Fordhook 



Do 



Snap: 



Stringless Black 



Valentine 



Do 



Potatoes : 



Irish Cobbler 



1949 

 Beans: 

 Lima: 



Henderson Bush-. 



Do 



Snap: 



Stringless Black 



Valentine 



Do 



Burpee Stringless 



Green Pod 



Do 



Cabbage: 



Early Jersey Wake- 

 field 



Golden Acre 



Corn, sweet: 



Country Gentleman 

 Golden Cross Ban- 

 tam 



Do 



Straw plus grain 

 do 



do._. 

 do- 

 do .__ 



do 



.do 



.do. 



Plants only 

 Pods 



Plants only 

 Pods 



Tubers 



Plants only 

 Pods 



Plants only 

 Pods 



Plants only 

 Pods 



Heads 

 Pods . 



Garden : 



Alaska 



Thomas Laxton 



Ears plus stover 



do 



Ears only 



Vines plus pods 

 do 



Pounds 



6.44 

 18.28 



8.87 

 18.95 

 24.58 



40.10 

 16.79 



61.74 



12.21 

 12.37 



20.11 

 15.78 



15.98 

 9.43 



24.24 

 27.34 



52.5 

 6.26 



20.74 

 17.80 



25 



50 



100 



200 



Pounds Pounds Pounds 



5.85 



24.69 



21.06 



8.83 

 15.46 



8.24 

 13.71 



14.36 

 17.81 



14.50 

 16.74 



13.84 

 3.13 



14.51 

 2.78 



29.51 

 13.45 



58.07 



13.28 

 13.59 



20.88 

 15.56 



16.49 

 10.00 



23.73 

 30.58 



n.i 



62.6 



7.14 



22.89 

 19.51 



5.48 



5.59 



17.75 J 19.46 



Pounds 



6.64 

 16.25 



Least 

 signifi- 

 cant 

 differ- 

 ence i 



Pounds 



0.56 

 1.71 



9.20 9.13 9.09 9.13 i (2) 



17.69 18.07 17.92 17.53 (-') 



21.19 ! 22.52 21.33 20.97 2.49 



8.48 

 13.64 



14.92 

 17.67 



13.93 

 2.95 



31.88 

 14.29 



62.56 



13.27 

 14.06 



18.91 

 13.76 



15.74 

 9.58 



21.60 

 27.93 



68.4 

 7.42 



24.94 

 19.66 



8.06 

 12.57 



15.08 

 17.81 



14.21 

 3.01 



26.11 

 11.53 



63.47 



12.52 

 14.11 



16.69 

 11.18 



13.81 

 7.43 



23.27 

 28.23 



72.2 

 7.55 



21.46 

 17.51 



10.78 



14.12 

 17.66 



11.81 

 2.80 



19.36 

 8.02 



9.78 

 11.32 



11.30 

 5.34 



9.18 

 3.50 



21.60 

 23.59 



[1.0 

 8.06 



19.56 

 12.60 



.77 

 1.74 



(2) 

 (2) 



1.92 

 (-') 



8.28 

 3.06 



( 2 ) 



1.48 

 1.68 



1.91 

 1.80 



1.22 

 1.14 



( 2 ) 

 (-') 



8.42 



8.42 

 (2) 



3.44 

 2.87 



1 At the 5-percent level. 



2 No significant differences. 



of DDT in the soil, up to 400 pounds per acre or more in the 

 soils employed in some of this work. 



As in the greenhouse tests, cabbage appeared relatively tolerant 

 to DDT in the soil. Although there was a slight drop in yield of 

 the 200-pound plots, the difference from the controls was not 

 significant. 



All the DDT treatments showed higher yields of sweet corn 

 plants (stover plus ears) than did the controls. Although there 

 appeared to be a tendency for the plant weights to increase with 



