104 PRODUCTION ON THE AMERICAN CONTINENT. 



to remain in the cooling room four or five days before baling, 

 or better, about two weeks, when not in haste to place them 

 on the market, as they are not then required to be dried 

 quite so much on the kiln, and allowed to finish in the 

 cooling room, which makes a softer, silkier sample, and one 

 not as liable to be broken and powdered in baling. 



Baling is performed in portable presses of sufficient power 

 to make a handsome bale, weighing about 200 Ibs. Care 

 is necessary in baling not to powder and break the hops, 

 as there is a great loss of strength by the lupuline sifting 

 out, and it also injures the appearance, upon which their 

 market value largely depends. 



In the years of 1866-68 the yield reached the almost 

 incredible amount of 2400 to 2500 Ibs. per acre, 2000 Ibs. 

 being considered a fair yield. Since then, owing partly 

 to a lack of care in culture, caused by a decline in price 

 for a few years below tl^e cost of production, and the 

 presence in the fields of the hop-leaf louse (Aphis humulus), 

 the average has fallen ; this insect appears on the lower 

 leaves of the vine about the middle or end of June. When 

 the weather is favourable (warm, muggy weather especially), 

 they increase so rapidly that they weaken the vine by sap- 

 ping the juice ; they do not do much damage usually until 

 the hop is fully formed and a few days before picking, 

 when, if the weather is hot and close, two or three days 

 are sufficient to almost destroy the whole crop. They 

 penetrate the hop after it is formed and suck the juice 

 from the tender bracts, and this piercing causes the juice 

 to exude, which, in dry or bright weather, evaporates and 

 does no damage ; but in damp, muggy weather the eva- 



