l"()ki;ST I'l.ANTlNC IX SOLTIIICRN MICHIGAN 133 



though no damage is apparent, as the enemies of Chermes seem to be 

 holding it pretty well in check. 



In addition to the scale, white ash has been badly damaged by a 

 twig borer. 



Climatic factors also have contributed their share to the c|UOta of 

 damage. A severe hail storm in l!)l(i caught the leaders of white pine, 

 Douglas fir, western yellow pine and Norway spruce just at the period 

 of rapid elongation and broke ofT from 10 to 15 per cent. A sleet 

 storm in the following year caused heavy damage to white pine leaders, 

 but very little in the case of other conifers. 



Uite frosts have killed back all new shoots at intervals of three to 

 four years on Douglas fir, Norway spruce, catalpa, Russian mulberry, 

 black locust, red oak. and white - . . The same frosts have killed the 

 newest leaves on yellow ])oplar. white ash, and black walnut but without 

 damage to the stems. 



Severe winter killing has occurred only with catalpa, osage orange, 

 and chestnut. Catalpa trees 14 years old were killed back to the 

 ground during the winter of 1917-18. 



Windfall damage has been limited to Scotch and Austrian pines, 

 caused by a wind of unusual strength in November of last year. 



All of the first plantings were established by first plowing and culti- 

 vating the areas thoroughly and then placing the trees in a slit made 

 and closed with a spade. With one exception, these were highly suc- 

 cessful, resulting in a catch of over 95 per cent. 



On a few areas, squares of sod were stripped ofif with a grub hoe 

 and the trees set in a slit made and closed with a spade. The soil was 

 a heavy clay, and subsequent growth has been slow, though the catch 

 was over eighty per cent. 



On all the heavier soils, cultivation of the area has resulted in a 

 dense stand of weeds for several years after planting, which not only 

 interferes with the development of the young plants but incurs the 

 hostility of neighboring farmers. As a result, all of the more recent 

 work has been done with the grub hoe. stripping the sod from a six- 

 tecn-inch square and digging a hole, not a slit, for the plants. The 

 catch with this method has varied from 50 to 95 per cent, the poorer 

 ones being due, in most cases, to unfavorable site conditions and poor 

 stock rather than to the planting method. 



Sowing has been done in drills and seedspots. Drill sowing, pre- 

 ceded by cultivation of strips has been very successful with red oak. 



