14 BULLETIN 44, U. S. DEPARTMENT OF AGRICULTURE. 



monest or only cause of blight, criticised the parasitic theory of the 

 disease. The fungus now seems to be generally accepted as the 

 commonest cause of the blight of pines in German nurseries, 1 though 

 it is recognized that other factors may also cause blight. Because 

 of the confusion arising from the controversy mentioned, the term 

 " schiitte " has often been made to cover indiscriminately all forms of 

 blight. It seems to the writer that the best policy will be to restrict 

 the English equivalent term, k ' needle-cast," to the damage done by 

 L oph od erm ium pinastH. 



In Germany infection is said to take place between the end of July 

 and the middle of September. The first reddening of isolated needles 

 occurs in late September. In a very late fall the needles may turn 

 brown and mature Lophodermium fruits appear before winter. Or- 

 dinarily the disease works very slowly during the fall and winter 

 and rapidly in March and April. By May, in severe attacks, 

 scarcely a green needle remains. Even with practically all the 

 needles killed, the weakened plants are frequently able to resume 

 growth at the terminal bud, though diseased trees are less able to sur- 

 vive transplanting than those not attacked. In some cases the para- 

 site in the infected needles is said to enter the stem and kill it also. 



The juvenile needles formed during the first year persist for a long 

 time after death, while needles of the mature sheathed form are shed 

 soon after death as a result of the formation of a cork separation 

 layer. It is this early shedding of diseased needles which gives rise 

 to the name of the disease. Spermatia are first formed on the fallen 

 needles. By the end of July mature ascospores appear, capable of 

 infecting healthy needles and thus completing the life cycle of the 

 parasite. It is not certain that in this country the life history of the 

 fungus would be the same as has been described for Germany. Some 

 of the confusion concerning etiology that has increased the difficulty 

 of separating needle-cast from other troubles can be traced to the fact 

 that Ebermayer's blight, as well as death of roots from early fall 

 freezing, may presumably cause the rapid death of the plants in early 

 spring. 



In needle-cast and related needle diseases the following characters 

 may be expected : 



(1) The first indication of disease in the needles will be the ap- 

 pearance of light brownish green spots. These will not be as likely 

 as most of the physiological diseases to attack the tips of the needles 

 first. 



(2) Ordinarily the needles on any one part of the plant will not all 

 die at the same time. 



1 Ilaack. Der ScMttepllz dor Kiefor. Zcitschrift fiir Forst- und Jagdwosen. .Tabrg. 43, 

 Heft 4, p. 329-357, pi- 4; Heft 5, p. 402-^23; Heft G, p. 481-505, 1 fig., 1911. 



