=) = eee 
200 BACTERIA IN RELATION TO PLANT DISEASES. 
98 per cent germinations and exposure for 5 minutes in water at 140° F. (60° C.) or below 
may be recommended as not injurious to wheat. 
Barley dipped for 30 minutes in copper sulphate water (1 pound to 4 gallons) gave 86 
per cent of weak germinations; and when exposed for 1 hour, 47 per cent. 
Wheat exposed to potassium sulphide (1 ounce to 1 gallon for 75 minutes gave 100 per 
cent germinations. Barley treated in the same way for 75 minutes gave go per cent germi- 
nations. Qats treated in same way gave 96 per cent gomins tous: but exposed for 19 
hours gave 42 per cent weak germinations. 
According to Cranefield (1901), formalin used as weak as 2.5: 1,000 (1 pound [pint] to 
50 gallons of water) for 20 minutes may injure oats used for seed. The experiments cover 
20 varieties of oats and the germination of over 25,000 seeds. The amount of injury varied 
greatly in different varieties, and was more noticeable in planted seeds than in those used in 
the germinating chamber. 
Longer exposures than 20 minutes at the standard strength (1 pint to 50 gallons) did 
not much increase the injury. The early growth from the treated seed was retarded and at 
no time did the treated quite equal the untreated in height. 
When more concentrated solutions of formalin were used the injury was progressively 
greater, ¢. g., 1 pint to 50 gallons of water, 91 per cent germination (check 94.5); 1 pint to 
25 gallons of water, 74 per cent; 1 pint to 20 gallons, 73 per cent; 1 pint to 10 gallons, 31 
per cent; 1 pint to 5 gallons, 12 per cent. 
In 1901, Windisch published many experiments on lupins, peas, horse beans, soy 
beans, corn, flax, rape, lucern, and clover, showing the effect of formaldehyde on germina- 
tion. Each of these wasin duplicate. The following are some of his conclusions: 
Per cent of Germinations. 
| Formaideli d (Per cent in Water.) 
| No. of | pistilled | ma al 
each | water. | | 
| 0.02 0.05 | 0.10 | 0.20 0.40 
| = Ne — ere See Pe 
icy | | | 
WHite Mpls oie iG a ohsidte erect 50 | 100 100 99 | 89 4 4 
VICtOrIa PEAS tee ete ete a eae | 50 84 80 56 19 6 12 | 
Horse beans ee. stn eos eee eee 50 | 100 97 100 | 98 94 26 | 
SOV Deane. a aro Gata aaa erick 100 99 98 07 92 4o | 6 
PIAR oes eteSe Catan co dine oo nae tee ee 200 97-75 94.25 Ber Uta cit Woceaa MOP AN MAPA acty ox 5 
MBIZ6 s oiieisicis oe idiscctais seine aaa t Delis eae a 100 | 100 100 100 99.5 100 94 
SURES T LANE 6 a 5.ci cise ssc pdesapaiaie Glacela yg grsteys aw tereys 200 98.25 80.25 4 2 i oieeaee alee at 
TNCORNE. pice t fia aloe Rous hearer One 200 90.50 88.75 27 ay ee 7 7.5 
Clover: 5 Mies paeseaa a cane as Oe ee 200 95.00 89.50 34 aE 3 8 4.5 
| 
No injurious action was observed on lupins, peas, horse beans, soy beans or maize, 
when the 0.02 per cent formaldehyde solution was used. 
Hiltner, in some root-nodule experiments, exposed soy bean seeds for 3 minutes and 
for 10 minutes to 1:100 mercuric chloride water, then carefully washed it away and planted. 
The plants came up badly, but this was not ascribed to the germicide. 
According to Dr. Windisch, winter wheat endured a soaking for 24 hours in 0.02 per 
cent formaldehyde, and in 0.04 per cent without lessening the power of germination. It 
also endured 0.08 per cent formaldehyde for 24 hours and gave a germination of 88.5 per 
cent at the end of 14 days. Exposure to 0.12, however, gave only 9.25 per cent germination 
at the end of 14 days, and exposure to 2 per cent gave o per cent germination at the end of 
14 days. Even the diluted’solutions delayed the germination somewhat. 
F. L. Stevens (1909) reports that treatment of oats with a solution of 1 ounce formalin 
to 0.5 gallon of water reduced germination to 37 per cent, while a solution of 1 ounce to 1 
gallon of water for 24 hours gave a germination of 73 per cent to 96 per cent, according to 
