26 BULLETIN 169, U. S. DEPARTMENT OF AGRICULTURE. 



Table VI. — Injury to pines and weeds by miscellaneous disinfectants — Continued, 





Disinfectant. 



Days from 



treatment 



to- 



Injury to pines. 





Plat. 



Substance 

 used. 



Per square 

 foot. 



Sow- 

 ing. 



Weed 

 exami- 

 nation. 



Weeds present in 

 plats. 





Ounces. 



Solu- 

 tion. 





P. divaricata: 1 

 Series 519 (G 







Pints. 









M o 1 1 u g o very 

 abundant, f ol - 

 lowed by grass, 

 Amarantnus, 

 Portulaca, and 

 Euphorbia in the 

 order named. 



checks). 

 F 



Ammonia 2 



Mercuric chlo- 



rid. 

 f....do 



^ Sodium chlo- 

 [ rid. 

 Lime-sulphur 



do 



Ferrous sul- 

 phate. 



Cupric sul- 

 phate. 



Hydrochlori c 

 acid. 



Nitric acid 



f-...do 



\Sulphuric acid 

 do 



0.5 

 .063 



.063 

 .188 



.313 



.75 

 .5 



.281 



.562 



1.125 

 .188 

 .125 

 .25 



.25 



.375 



( 4 ) 



(*) 



2 

 2 



} 2 



2 



2 



2 



3 

 3 



3 

 1 

 1 

 2 



3 

 3 



34 

 













 



34 







34 

 34 





 34 



34 



34 



Few 



Few 



66 

 32 



32 



32 



32 

 32 



66 



32 



66 



}• 32 



66 



66 

 66 

 32 



32 



Record lost 



( 3 ) 



All seed killed 



Three-fourths o f 

 the seed killed 

 by unknown 

 factor. 



Germination good. 



Record lost 



Moderate to heavy.- 

 Very heavy 



Record lost 



Very slight 



Record lost 



do 



do 



U 



V 



None. 

 Do. 



R 



S 



L 



Records lost. 



None. 



Nearly as many as 

 in checks. 

 Do. 



Grass, very few 

 plants at edge of 

 plat. 

 Do. 



Do. 



K 



P 



M 







C 



Grass and Mollugo, 

 each 7 or 8 plants; 

 Amaranthus, 1. 



Grass, 3 plants. 



Grass, 7 or 8 plants. 



Grass, 7 or 8 plants; 

 Portulaca, 1 or 2. 



D 



do 



A 



do 



H 



Heat, 80° C. or 

 greater for 

 not less than 

 10 minutes. 



do 





G 



do 











1 Watered 0.3 inch, twice daily. 



2 Plats covered tightly for 3 days after treatment to prevent too early evaporation. 



3 Nearly all seed killed; heavy injury to those which germinated. 

 * Upper 2\ inches of soil heated. 



s Upper 6 inches of soil heated. 



DISCUSSION OF MISCELLANEOUS DISINFECTANTS. 

 HYDROCHLORIC AND NITRIC ACIDS. 



Hydrochloric and nitric acids were used in series 501, plats C and 

 J; 512, plats A, C, D, F, G, and K; 514, plats F and G; 516, plats 

 A and C; 518, plats F and P; and 519, plats M, O, and P (Table VI). 

 Injury by them seems to take place in just the same way as that 

 caused by sulphuric acid, and the injured seedlings presented the 

 same appearance as those injured by sulphuric acid. (See PI. I, 

 figs. 2 and 3.) Pine seeds were not killed by the amounts used at 

 sowing, but the apices of the radicles in some plats were killed by 

 the acid residue hi the surface soil after germination began. Injury 

 may be prevented, as with sulphuric acid, by waterings sufhciently 

 frequent to prevent the concentration of the acid in the surface soil. 



