116 BOARD OF AGRICULTURE. 



weed, and to manure well with manure from the pigsty. No 

 well-understood remedy is known against the attacks of blight 

 and mildew. They most frequently infect the hop in seasons 

 when the days are hot and the nights dewless ; and a frequent 

 use of ashes is recommended as a remedy. 



Besides the diseases which attack the hop, there are insects 

 which infest it; and among others the ghost-moth, [Hepiolus 

 humuli,) which lives in the root of the hop, and sometimes 

 proves very destructive. A small green fly also infests the 

 hop, and commits extensive depredations, sometimes even de- 

 stroying much of the crop. This insect appears at the end 

 of May, and in June. Syringing the field with tobacco water, 

 soapsuds, <fcc, has sometimes been resorted to. I would 

 suggest the use of quassia by way of experiment. This is the 

 infusion of the bark and wood of the quassia tree, from the 

 West Indies, of an exceedingly bitter taste. It may be ob- 

 tained at most of the drug stores, and applied with the syringe 

 with perfect safety and at small expense. A change of loca- 

 tion once in eight or ten years seems to be the only remedy 

 against the larva3 of some insects which attack the roots of 

 this plant. 



The hop has sometimes been called an exhausting crop. I 

 know of no valid reason for this opinion other than the sup- 

 position, that, as the vines are large and luxuriant, they must 

 necessarily draw upon the energies of the soil. But when we 

 consider how large a proportion of their nourishment all 

 plants, and particularly all plants which spread out a large 

 surface of leaves, draw from the atmosphere, this supposition 

 seems to have little weight. Whether exhausting or not, it is 

 certain that after a hop plantation is discontinued on one spot, 

 which should ordinarily be at the end of about eight or ten 

 years from the time of setting, grass succeeds better than after 

 most other crops. Indeed, all crops grow with the greatest 

 luxuriance after a hop crop, and the soil is by no means ex- 

 hausted for the hop itself. The necessity for a change of location 

 arises mainly from the fact that insects are most apt to infest old 

 grounds ; and were it not for this reason, hops might be culti- 

 vated many years in succession on the same land. It is the 

 practice of one of the largest growers with whom. I am ac- 



