SCAB OF APFLES. 237 



for the development of fungous diseases. In early spring one or two good 

 waterings per week may prove sufficient. Later in the season on clear, 

 warm days one or possibly even two waterings may be necessary in one 

 day. In cool weather it is well to apply the water in the early forenoon 

 that the plants will be dried off by the heat of the day and the tempera- 

 ture raised before the bed is cooled by the night air. 



THE SCAB OF APPLES. 

 By Fred W. Crysler in Fruit Belt. 



Fruit growing is oftentimes seriously interfered with by plant dis- 

 eases, so much so that in order to be a successful fruit grower one must 

 have a general knowledge of their nature, means of perpetuation, mode 

 of attack, and also how they affect the host. 



Now plant diseases are caused by lower plants, very minute, called 

 fungi, which prey upon the higher plants, the hosts, interfering with the 

 normal functions of their parts or destroying them altogether. Fungi 

 are reproduced by spores, which answer the same purpose as seeds do in 

 the higher plants. But the growing injurious part of fungi is known as 

 the mycelium, which, in case of scab, develops beneath the skin of the 

 leaf, twig, or fruit and comes from a little germ tube sent through the 

 tender skin from a spore. 



Scab is one of the worst diseases of the apple and appears in the 

 spring on the young leaves as slight elevations of a lighter color than the 

 surrounding surface. Soon there appear little tufts of olive colored 

 patches on the leaf surface. These are the fruiting branches of the fungus 

 and at the ends of which spores are borne, which are carried by wind, 

 rain, or some other way to infect other leaves or fruit. 



In this stage of the disease the function of the leaves is interfered 

 with so that the plant can not get sufficient food required for the time 

 nor for future growth and fruit. In severe cases the leaves become de- 

 formed and fall prematurely, leaving the plant less resistant to future 

 attacks of red and other diseases. But perhaps the most serious effect 

 in a financial way is in the case of the fruit. With this a spore from a 

 diseased leaf alights on the young fruit soon after the flower has fallen, 

 and if the weather is cool and moist the spore germinates and sends out 

 a little germ tube which forces its way through the tender skin and pro- 

 ceeds to form a new mycelium and reproduce a new crop of spores. The 

 result is the young tissues of the fruit fail to develop, and the lopsided, 

 deformed, and badly cracked apple remains to advertise the willful neglect 

 of the 5vould-be fruit-grower. Scabby apples are worthless for market 

 purposes and of but little use for other purposes. 



The injury from scab does not stop here, as the ruptures in the 

 skin of the fruit afford a fine entrance for rots, known as bin rots, one 

 of the worst of which is pink rot. This rot gains entrance through the 

 broken skin of the fruit, as it is unable to penetrate unbroken skin, and 

 this condition is furnished by the scab. It develops most rapidly when 



