5S . JOUENAL OF AGRIGULTUEE OF P. E. 



twenty minutes, or by a one per cent formalin solution applied at 

 the rate of one gallon of solution per square foot of surface. In the 

 latter event the area treated is covered with sacking or other cover- 

 ing for several days to permit the formalin fumes time to act, and 

 the soil is then worked over thoroughly before planting. 



CROWN ROT. 



True damping off attacks the seedlings only in the very early 

 stages, and before the stem tissues have hardened. Another type 

 of disease similar in its action has l)een noted which, however, at- 

 tacked after the seedlings were some months old and had attained 

 a considerable length of woody stem. The bark at the surface of 

 the ground and finally for several inches upward was soft rotted, and 

 the infected plants girdled. This disease also occurred in spots 

 which enlarged rapidly. 



The cause was a fungus tc^-hnieally known as ISclcrotium Rolfsii, 

 which is also the cause of a leaf disease of sugar cane, and a serious 

 wilting of eggplant, pepper, tomato, and other crops. Under very 

 moist conditions the vegetative growth of the fungus itself can be 

 seen at the base of infected plants as a delicate, white membrane, 

 on which are produced the sclerotia, or fruiting bodies. These are 

 hard, globular, and yellow to brown in coloi', much resembling 

 mustard seeds. 



This disease is somewhat more difficult to control than ordinary 

 damping off, but much again can be accomplished by careful drainage 

 and prevention of overcrowding of seedlings, conditions very favor- 

 able to the parasite. Seedlings of the age attacked by Sclerotium 

 can usually be transplanted, so that the fungus can be headed off 

 by moving all healthy plants to a new location, spacing them prop- 

 erly, and arranging for drainage. 



BENCH BOOTING. 



A mechanical defect of citrus seedlings of very frequent occur- 

 rence is that known as bench rooting or twisting of the root. A sim- 

 ilar trouble has been studied in rubber seedlings in Ceylon, and doubt- 

 less is to be found in seedlings of other economic plants. The twisting 

 of the root interrupts or interferes with the passage of the sap and 

 so finally may cause a stunting of the tree. It is apparent that these 

 abnormalities originate during the germination of the seed, and are 



