142 THE CULTIVATED EVERGREENS 



Sun-scorch. 



This important trouble occurs on all conifers during the 

 growing season, in hot, dry weather, especially when the 

 seedlings or transplants are dense and the soil is sandy. It is 

 due to more water being given off by the plants than is ab- 

 sorbed by their root systems. In serious cases seedlings of all 

 ages are killed outright, but when it is less severe, only parts 

 of the plants may die. The needles first turn yellow, com- 

 mencing at their tips, and then gradually become a deeper 

 brown color and finally nearly red. There is a simultaneous 

 death of the root system. Owing to the fact that affected areas 

 are often in well-defined patches in certain beds, the trouble 

 is at times mistaken for one due to a fungous attack. The 

 relation of the blight to the weather conditions, crowding, and 

 soil character will, however, usually help one to diagnose the 

 trouble correctly. 



Complete control may be obtained by heavy watering, at 

 least once a week after the seedlings are over two months old. 

 Lath shades, as described under "damping-off," or some other 

 means to the same end, will also prove helpful. Crowding of 

 the seedlings and extremely sandy soil should be avoided. 



Whitespot. 



A type of injury which may be mistaken for damping-off 

 sometimes appears in coniferous seed-beds in very hot weather, 

 particularly when the soil is very porous and black. Small, 

 somewhat sunken lesions, which are light in color and have 

 quite a definite margin, appear at the base of the stems. The 

 lesion is often only on the side of the stem which faces the 

 south, but it may encircle the whole stem. Seedlings thus 

 affected may remain turgid and upright for several days but 

 sooner or later they fall over and die. This is often due to 



