6 



CIRCULAR 411, U. S. DEPARTMENT OF AGRICULTURE 



19 days previous to harvest, and when dusted with undiluted calcium 

 arsenate 30 days before harvest. At Baton Rouge, on the Copen- 

 hagen Market and Charleston Wakefield varieties, the legal tolerance 

 was exceeded on plants dusted with all dilutions of paris green used 

 and with calcium arsenate and lime (1 to 5) 8 to 10 days previous to 



Table 4. — Arsenic residue 1 on cabbage dusted ivith different quantities, dilutions, 

 and numbers of amplications of varis green and calcium arsenate, Baton Rouge, 

 La. 



From last dusting to sampling 



Total 



appli- 

 ca- 

 tions 



Residue of AS2O3 per pound of marketable cabbage 





Dura- 

 tion of 

 period 



Rain- 

 fall 



Paris green diluted with 

 lime 



Calcium arsenate diluted 

 with lime 



Period 



To contain 

 arsenic 

 trioxide 



Parts by 

 weight 



• 



Parts by 

 weight 



To contain 



AS2O3 

 equivalent 





10 per- 

 cent 



5 per- 

 cent 



ltolO 



1 to 9 



1 to 5 



Undi- 

 luted 



10 per- 

 cent 



5 per- 

 cent 



Experiment 1: 



May 5-May 15 



Days 

 10 



17 

 25 

 33 

 42 

 49 

 61 



Inches 

 0.00 

 1.22 

 4.26 

 6.39 

 8.63 

 9.10 



11.09 



Num- 

 ber 

 7 

 6 

 5 

 4 

 3 

 2 

 1 



Grain 



Grain 



Grain 

 0. 0134 



:0046 

 .0019 

 .0016 



.0028 

 .0019 

 .0016 

 .0019 



. 0238 



.0029 

 .0022 

 .0013 

 .0013 

 .0015 

 .0018 



.0105 



. 0035 

 .0019 

 .0008 

 .0006 

 . 0003 

 . 0003 

 .0003 

 .0003 



Grain 



Grain 

 0. 0162 



.0022 

 .0014 

 .0009 

 .0009 

 .0009 

 .0011 

 .0014 



.0161 



.0040 

 .0019 

 .0020 

 .0020 

 .0041 

 .0012 



.0315 



. 0043 

 .0103 



.0016 

 .0005 

 .0008 

 .0007 

 .0007 

 .0003 



Grain 



Grain 



Grain 



Apr. 28-May 15- 

 Apr. 20-May 15__ 

 Apr. 12-May 15.. 

 Apr. 3-May 15._. 

 Mar. 27-May 15. 

 Mar. 1 5-May 15. 

 Checks 









































































Experiment 2: 



May 1 3-May 23 



10 

 20 

 28 

 36 

 46 

 55 



.00 

 .02 

 2.53 

 4.92 

 6.68 

 9.10 



6 

 5 



4 

 3 

 2 



1 













May 3-May 23 ._ 

 Apr. 25-May 23._ 

 Apr. 17-May 23.. 

 Apr. 7-May 23__. 

 Mar. 29-May 23. 

 C hecks 































































Experiment 3: 



10 

 18 

 28 

 38 

 45 

 53 

 61 

 72 



.35 

 1.96 

 1.96 

 1.96 

 3. 18 

 6.22 

 8.35 

 10.59 



8 

 7 

 6 

 5 

 4 

 3 

 2 

 1 













May 25-June 12 













May 15-June 12- 

 May 5- June 12___ 

 Apr. 28-June 12.. 



Apr. 20-June 12_. 

 Apr. 12-June 12.. 

 Apr. 1-June 12... 

 Checks 









































































Experiment 4: 



Dec. lS-Dec. 26 



8 

 18 

 24 



.70 

 .70 

 1.80 



6 

 5 



0.0122 



.0052 

 .0015 

 .0014 



.0100 



.0033 

 .0015 

 .0017 



f 



0. 0117 



.0049 

 .0025 





0.0179 



.0049 

 .0022 



0. 0069 



Dec. 8-Dec. 26 











.0037 



Dec. 2-Dec. 26 











.0010 



Checks 











.0003 



Experiment 5: 



Feb. 20-Feb. 28 



8 

 15 

 26 



1.13 

 3.33 



5.08 



9 



8 



.0135 



.0063 

 .0015 











.0170 

 .0108 



.0087 



.0203 



Feb. 13-Feb. 28 











.0333 



Feb. 2-Feb. 28 . 











.0070 













.0007 



Experiment 6: 



9 

 17 

 26 



.32 



.45 



2.52 



4 

 3 

 2 







0. 0042 

 . 0035 

 .0039 

 .0042 

 .0008 

 .0021 

 .0011 

 .0009 

 .0006 

 .0003 

 .0005 



( 2 ) 

 .0003 





0. 0305 

 .0320 

 .0147 

 .0338 



.0096 

 .0041 

 .0047 

 .0039 

 . 0003 

 .0005 

 .0006 

 .0005 

 .0003 



















Apr. 28-May 7— _ 















1 



































Apr. 20-May 7... 



1 

























f 











Apr. 11-May 7___ 



































C hecks . 



























■ 



1 Treatments leaving a residue exceeding the legal tolerance of 0.01 grain of arsenic trioxide per pound 

 of marketable product are shown in bold-faced type. 



2 Trace. 





