BLIGHTS OF CONIFEROUS NURSERY STOCK. 19 



This survival of the root after the death of the top distinctly sep- 

 arates this trouble from those of the root-rot and sun-scorch types. 

 The experience of a number of nurserymen shows that the disease 

 can nearly always be prevented by using only loose, light material 

 to mulch with and mulching no more than is absolutely necessary. 

 Spraying with Bordeaux mixture just before the mulch is put on is 

 worth a test at any nursery where mulch injury is frequent. 



RED-CEDAR BLIGHT. 



In western nurseries where red cedars (Juniperus virginiana L. 

 and /. scofulorum, Sarg.) are grown for ornamental planting there 

 is a great deal of trouble with a blight of unknown origin. A num- 

 ber of nurseries have nearly or entirely stopped trying to grow cedar 

 on this account. The disease is described as sometimes working sud- 

 denly over a considerable area of seedlings and transplants. Since 

 attacks are said to occur when adjacent pines are perfectly healthy 

 it is not likely that sun scorch is responsible. In large transplants 

 all the needles on specific twigs and branches die at once, indicating 

 a parasitic twig blight. In the cases observed by the writer there was 

 no evidence of any constriction of the twigs such as Tubeuf * has 

 figured for Pestalozzia funerea twig-blight on Chamaecyparis men- 

 ziesii. 



So little is known concerning the trouble that no recommendations 

 for its control can be made. It is suggested that the nurserymen who 

 have the most trouble with the disease conduct experiments separately 

 with watering, moderately heavy shading, and frequent spraying 

 with soap-Bordeaux mixture on numerous small-scale experimental 

 plats scattered through their beds. One of these methods should 

 prevent or partly prevent the disease. A comparison of attacks on 

 treated and untreated plats should give information both as to the 

 nature of the disease and the best control method. 



MECHANICAL ROOT INJURY. 



It often happens that trees which die in the nursery can be pulled 

 up very easily. Examination shows that the root has been either 

 broken or eaten off 1 to 3 inches below the surface of the soil. This 

 presumably is done by grubs. This type of loss is mentioned merely 

 to keep it from being confused with any of the types of blight 

 described in this paper. 



CONCLUSION. 



A number of different blights concerning which little has been 

 known do considerable damage to conifers in nurseries in the United 

 States. The increasing amount of forest planting and the danger 



1 Tubeuf, Karl von. Loc. cit. 



