June a» 1923 
Snow Molding in Coniferous Nursery Stock 
745 
Since this investigation was completed Cornefert ® has reported a 
somewhat different method which has given excellent results for several 
years in the protection of spruce nursery stock from Herpotrichia nigra. 
In the autumn peded poles lo to 15 cm. in diameter are placed between 
the rows of plants, so ^at the plants lean upon them when pressed down 
by the snow. In fidd planting each tree is placed so that it can be sup¬ 
ported by a rock or a stump. 
Table III shows the original germination per square foot, survival on 
various dates, and the special treatment applied to each of the beds 
sown in 1918. The use of the protective framework of 2 by 6 inch 
planks was again checked during the winter of 1920-21 on Douglas fir 
seedlings originating from seed sown in the spring of 1920, the survival 
data for which is also included in Table III. The general appearance 
of the 3~o beds of the 1918 sowing are shown in Plate 2, A. From 
Table III it will be seen that the results are decidedly in favor of the 
plank framework (Bed 14 of the 1918 sowing and Bed 7 of the 1920 
sowing), which keeps the heavy mass of snow from mashing the seedlings 
down flat against the soil. Sufficient snow sifts through the intervening 
spaces between the 2 by 6*s to keep the soil moist during the winter. 
At the end of the third winter Bed 14 of the 1918 sowing showed an 
average survival of 84 seedlings per square foot, or 60 per cent of the 
original germination compared with the next highest survival of 14 
seedlings per square foot, or ii.i per cent of the original germination in 
Bed 12—^the control bed to which no special treatment had been applied. 
During the winters of 1918--19 and 1919-20 the protected bed (No. 14) 
suffered losses of 2.4 per cent and 14.2 per cent and none at all during 
the succeeding winter, as compared with losses in the control bed (No. 12) 
during the three winters of 17.6, 28.5, and 22.2 per cent, respectively. 
Bed 7 of the 1920 sowing, which was given protection by the same type 
of framework covering as that described above, suffered a loss of 6 per 
cent during the winter of 1920-21, as compared with ^ loss of 49.2 per 
cent in the control bed during the same winter. 
It is evident from Table III and from general observations in the 
nursery that a mulch of organic matter stimulates the activities of the 
fungi by providing a suitable substratum on which they may develop. 
Contact with various kinds of organic matter, dead snow-molded plants, 
and a surface even with the soil predisposes to the disease. 
On May 25, 1921, the stock in Bed 14 (protected by framework) and in 
Bed 12 (control) was dug and graded with the result that 67 per cent of 
the stock from Bed 14 was suitable for transplanting, while only 34.4 per 
cent of the seedlings from Bed 12 was suitable. Even many of the firsts 
in the unprotected bed were infected with the snow-molding fungi, which 
probably would result in a heavier culling the following spring when the 
transplants were dug preparatory to field planting. The foliage was of a 
dull green color and numerous leaves were dead or partially killed. This 
lot of stock had very few healthy buds, only 25.5 per cent, while the 
seedlings from the protected bed had 90.7 per cent of good terminal buds. 
In each case the bud scales of the unhealthy seedlings were loose and 
flaccid, giving the buds a withered appearance. Small bunches of each 
lot of stock were allowed to stand in the laboratory with the roots sub¬ 
merged in water for 10 days. Practically all of the buds on the seedlings 
• CoRNBFBRT, R. r^oAnAration sur i,bs hauts pj:.AtBAUX DU JURA. In Soc. Forest. Franche-Comt^ 
et Belfort Bui. Trimest., t. 14, p. 206. 1921. 
