34 



" Fungi may be divided into two general classes : those growing 

 upon dead and decaying matter, or saprophytes ; those feeding upon 

 living tissue, or parasites. By far the larger portion possessing in- 

 terest to the horticulturist belong to the latter class, for in this are 

 included the fungi which do so much injury to cultivated plants. 



" Yet all pirasitic fungi do not attack the host-plant in the same 

 manner. Some immediately penetrate into the interior tissue, and 

 there they nourish, being well protected from outer influences by the 

 exterior covering of the plant The fungi c iusing all the more serious 

 diseases develope in this matter and in fact, the vast majority of plant 

 diseases are caused by such organisms. There are others, however, in 

 which the body of the fungus is almost entirely upon the surface of 

 ' the host-plant, only a comparatively small number of threads penetrat- 

 ing the tissues in order to obtain nourishment These parasites can be 

 rubbed off, and unless the attack has been very severe, the given, 

 healthy tissue will be seen underneath. This class may for convenience 

 be termed "surface fungi;" to distinguish them from those which 

 grow within the host-plant ; it is represented by the common powdery 

 mildew of the grape, one mildew of the gooseberry, one of the straw- 

 berry, and a few others. 



" The life histories of the various fungi must form the basis for any 

 methods of treatment which may be adopted. During certain stages 

 of their existence, parasitic fungi may be checked quite easily, and at 

 such times the remedies should be applied. 



" It is evident that when a fungus has once become established in- 

 side the host-plant, it cannot be reached without destroying the tissue 

 of the host in the affected places, which is by no means desirable. The 

 fungus must be destroyed before it enters the host ; in other words, 

 the spores miist be killed as soon as they germinate or better they 

 must not be allowed to germinate. All applications must be preven- 

 tive, not curative, since a care is practically impossible when the 

 fungus is once established, unless it grows upon the surface of the host, 



" The line of treatment indicated is this : to cover the stems and 

 foliage of the cultivated plant with some substance that will destroy 

 the spores which may be present, as soon as they germinate, or with 

 one that will have the power of preventing this germination. If that 

 is done, the plant will remain healthy, so far as fungi are concerned ; 

 otherwise it will not, unless, indeed, no fungus attacks it. Several 

 substances which destroy these spores, as we'll as the surface fungi, 

 have already been found. They are easily applied, safe, and effective, 

 and any grower who suffers his fruit to be ruined by these parasites is, 

 as a rule, deserving of his loss, for means of destroying the pests are 

 at his command It is largely the grower's fault if his apples are scabby, 

 if his grapes are mildewed, and if his potatoes rot in the field. Spray- 

 ing is no longer an experiment, it is a necessitj' ; and those who re- 

 cognize this fact are the ones who are reaping the rewards. 



Spray Machinery. 



" The best spray nozzle, so far as efficiency, simplicity, and cheap- 

 ness are concerned, is the end of a hose and a man's thumb. Unfortu- 

 nately the thumb gets sore and tired, and operations must be suspended 

 to wait for repairs. It is the nearest approach to the ideal nozzle yet 

 -devised, if it were only more practicable. It will do all that a good 



