THE HOP PLANT. 45 



Diseases Produced by Conditions of Soil and Climate. 



The following diseases of the hop plant are brought about 

 by bad weather, bad soil or mechanical injury : — 



1. Leaves turning yellow. 



2. Summer or sun brand. 



3. Cones dropping off. 



4. Honey dew. 



5. Damage by wind, rain and hail. 



1. Leaves Turning Yellow. 



This complaint may appear at various stages of the plant's 

 development, and is due to a multiphcity of causes. The 

 outward manifestation is the gradual yellowing of the leaves, 

 commencing with the lowest, so that finally the whole plant 

 looks sickly. It most frequently appears in gardens where 

 the subsoil is impermeable, and if swampy places are formed 

 in drained gardens by the stopping of the drains, such places 

 will soon be indicated by the fact of the hop plants turning 

 yellow. 



When the soil is excessively damp, disturbances in the 

 nutrition of the plant will take place in the same manner 

 as in other cultivated plants ; and the low temperature of 

 the wet soil has an unfavourable influence on the well-being 

 of the bine, which will inevitably become diseased if exposed 

 to such unfair conditions for any length of time. 



The water in the soil may also attack the stocks at any 

 place where the latter have been injured either by animals 

 or by carelessness in working the ground. In such event the 

 roots begin to rot and canker — another cause of the leaves 

 turning yellow ; and it is worthy of note that plants which 

 are rotting at the roots produce very few cones, if any; 

 Should the rotting occur after the cones are formed, it will 



