Daffodil Diseases 253 



Yellow Stripe 



Cause, improper cultural conditions. 



Symptoms. Yellow stripe is a disease which is 

 more commonly met with tmder field conditions, 

 but also appears on daffodils under glass. The 

 trouble in its early stage is perceptible as a slight 

 discoloration, or a yellowing of the veins of the 

 leaves. In an advanced stage, the leaves become 

 streaked with parallel bands of yellow. In ex- 

 treme cases, the leaves wither and the plants fail 

 to set blossoms. The disease was studied by Dar- 

 lington,* who decided that the cause of it is not 

 a parasitic organism, but that it is due to some uni 

 favorable cultural conditions that are as yet unde- 

 termined. No methods of control are known. 



Erica (Erica spp.) 



Cultural Considerations. Ericas are low growing 

 evergreen shrubs which lend themselves admirably 

 to forcing on a commercial scale. Too much or 

 too little water is injurious to the plant especially 

 during the blooming period. The plants should 

 never be allowed to wilt. The pots should be reno- 

 vated every year individually and the proper amount 

 of water given. The plants also need all the ven- 

 tilation possible. 



* Darlington, H. R., Jour. Roy. Hort. Soc. (London) 34: 161-166, 

 1908. 



