NOTES 1009 



Notes on Nursery Stock of White Pine 



On May 28, 1915, a limited test of the effect of puddling white pine 

 nursery stock was made at the Harvard Forest School, Petersham, 

 Mass., by the writers. The resulting data, while too scanty to be 

 conclusive on the widely discussed question of puddling, point to the 

 conclusion that the gain, if any, is too slight to be worth the trouble. 

 The test also demonstrated the surprising ability of white pine seed- 

 lings to withstand abuse, as previously pointed out by Ziegler.^ 



Conditions. — A clear day, with frost at sunrise, and a maximum 

 temperature of 51° F. about 3 p. m. Very high northwest wisds, 

 giving a wind movement of 209 miles between 8 a. m. and 8 p. m. at 

 the nearest Weather Bureau station at Amherst, Mass., about 30 miles 

 distant. Mean relative humidity at Amherst, 44.5. Place of ex- 

 posures, in full sunlight, sheltered from the full force of the wind, 

 but exposed enough to make it necessary to weight the exposed seed- 

 lings with small rocks. Exposures were made on an old door placed 

 horizontally on the ground. 



Stock.- — White pine (P. strobus) two year seedlings, grown in a 

 rather dense stand of about 8,000 per bed of 48 square feet. Source 

 of seed, Michigan. In an effort to make the trees tender, they were 

 dug and heeled in, without puddling, four weeks previous to the date 

 of the test. Growth had started while the trees were heeled in. 

 Average length of new growth, 1>4 inches. The trees for this test 

 were carefully graded to secure uniformity of size, vigor, new growth, 

 and root systems. 



Exposures. — The trees were exposed in lots of 20, half puddled and 

 half not puddled, and were left in the full sunlight and wind for the 

 periods indicated in the table. The puddle was rather thin, but coated 

 the rootlets completely. At the end of the period of exposure, the 

 trees were root pruned rather severely, and at once placed in transplant 

 rows in fresh, soft earth, ideal for transplanting. The roots of the 

 puddled trees were separated if they had been matted by the puddle. 



Record of Residts. — The following table shows the survival at the 

 end of one week and of two weeks. The test was then abandoned 

 as other factors, including loss from white grubs, made further results 

 uncertain. 



'For. Quart. 12, p. 31, and 13, p. 163. 



