The Botrytis Blight of Tulips 357 



2. Careful handling, to avoid injuring the bulbs, as infection takes 

 place more readily on injured bulbs than on healthy ones. 



3. Storage of the bulbs under proper conditions of temperature and 

 humidity. The temperature should be kept as low as possible without 

 injury to the bulbs, preferably about 40° F. The humidity also should 

 be low. These conditions are especially desirable, as they retard the 

 development of any small lesions that may be present on the bulbs at 

 the time of storage, and prevent the germination of any conidia that 

 may be on their surface. 



4. Removal and destruction of diseased plants when they appear in 



the field or the beds. This will limit, if it does not entirely prevent, 



secondarv infections. 



SUMMARY 



An investigation of the tulip disease caused by Botrytis Tulipae (Libert) 

 comb, now shows that it is present throughout the United States and that 

 it was probably introduced with the introduction of tulip bulbs. Reports 

 of the disease show that it has been in this country at least since 1901. 



Under normal conditions this disease is restricted to the genus Tulipa 

 and within this genus practically all varieties are susceptible. One instance 

 of apparent immunity is the variety Baronne de la Tonnaye, which, during 

 an epidemic of Botrytis blight, showed no evidence of the disease. 



Counts made in the spring of 1917, at Ithaca, on one variety of late 

 tulips. Spathulata, showed 100 per cent of the leaves and 98 per cent 

 of the stalks to be affected. Other varieties were similarly infected. 

 These infections were traced to the bulbs, of which the variety Spathulata 

 showed 4.6 per cent with unmistakable Botrytis lesions and the Mrs. 

 Grover Cleveland variety, 5.2 per cent. 



The disease is easily recognized on the bulbs when the fungous sclerotia 

 are present in the lesions. On the leaves, the flower stalks, and the flowers, 

 a severe blighting frequently takes place. 



Studies of the literature and herbarium specimens show that the disease 

 under consideration is to be ascribed to Botrytis Tulipae (Libert) comb, nov. 4 



Cultural studies have demonstrated that both the small sclerotia on 

 the bulbs and the conidial form on the leaves and other parts of the tulip 

 plant are stages of one and the same fungus, namely, Botrytis Tulipae. 



«In recent literature the fungus has goneby the name Bolrytu parasitica Cavara, but the specific name 

 of Libert has priority. 



