90 STATE HORTICULTURAL SOCIETY. 



iug. This slionlfl serve as an incentive for every nian in the coniniuiiity 

 to sijray and thereby help in tlie iv^hi of eradicalinu one of the w(»ist 

 pests of the frnit grower. 



THE RCA P. OF APPLES. 



FRED W. CRYSLER. 



Fruit growing is oftentimes seri(»nsly interferred with by ph^nt 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. 



TS^ow plant diseases are caused by loMer 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 ansAver the same purpose as seed do in 

 the higher plants. But the growing injurious part of a fungus is known 

 as the mycelium which, in case of scab, develoi)s beneath the skin of the 

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

 tlie surrounding surface. Soon there appear little tufts or olive colored 

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

 fungus and at the ends of which s])ores are born 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 ]>lant cannot get sufficient food required for the time 

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

 formed and fall i)renniturely leaving the plant less resistant to future 

 attacks of scab 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 thru the tender 

 skin and proceeds to form a new mycelium and reproduce a new crop of 

 spores. The result is the young tissues of the fruit fails to develop and 

 the lop-sided, deformed and badly cracked api)Ie remains to advertise 

 the willful neglect of the would-be fruit gro\Aer. Scabby apples are 

 worthless for market i)ur])oses and but little for other pur])()ses. 



The iujury from scab does not slop 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 fruits as it is unable to ])enetrate unbroken skin and this 

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

 scabby fruit is stored in large (|uantities in sheds, cellars or piles where 

 atmospheric conditions are damp and close. Here it completes the de- 

 struction begun by the scab, and even when fruit attacked by it is 



