316 MINNESOTA STATE HORTICULTURAL SOCIETY. 



PEAR AND APPLE BLIGHT. 



H. E. VAN DEMAN, PARKSLEY, VA. 



This species of blight is due to a very minute germ which finds 

 access to the tender cells and juices inside the protecting bark of 

 the tree. There is multiplies into the untold billions, turning the 

 healthy sap into a poisonous fluid, and causing serious injurj'- or 

 death to a part of a tree and in extreme cases to the entire tree. 

 What will stop it? When the blight is rampant in the orchard, very 

 little, if anything, can be done to stop it. The dead and dying leaves 

 and branches are but the natural results of the disease that has 

 long been ravaging the vital parts within. It is the sickly portion 

 of a blighted leaf or branch that contains the elements of danger. 



Fighting fire blight can only be done effectively by preventative 

 measures. Nothing will cure it, so far as known, short of fire. Nor 

 will spraying even check it. The disease is too deeply seated to be 

 reached by outside treatment. It will go from apple to pear or 

 quince trees, or from them to the apple. The wild red haws 

 and some other pornaceous trees are slightly effected 

 by it. The germs will not multiply when the temperature is 

 cool. They lie dormant during the winter time, and under 

 the warming influences of spring they begin to grow. A liquid 

 oozes out of the diseased branches, which contains millions of these 

 deadly germs. This is carried on the feet of insects and in other 

 ways to neighboring trees, where the germ finds lodgment. They 

 are often introduced through the delicate floral organs, where they 

 find easy access to the circulating sap. From there the disease 

 soon spreads into the twigs and then into the larger branches. They 

 also enter through the tender growth of the new wood. It is there 

 that the disease most commonly appears, especially on apple and 

 quince trees, during the warm, sultry weather in June and July, 

 when the shoots are very tender. Where thunder showers are very 

 frequent in mid-summer, the conditions are just right for the intro- 

 duction and propagation of the disease, which has caused some to 

 think that electricity did the damage. 



As has already been said, preventive measures are the only kind 

 to use. The source of infection must be destroyed. If the sickly, 

 half-matured twigs are cut off below where any disease exists there 

 can be little opportunity for its spread. The great difficulty is, to 

 know when we are below the disease. No one can tell absolutely 

 how far down it may extend, except the most skillful scientist, and 

 with a compound microscope. It is usually safe, however, to cut a 

 foot or a little more below where there is the least outward sign of 

 any affection. If the cut is not made below the diseased part, there 

 is great danger, if not certainty, of carrying the germs on the knife 

 or saw to healthly wood in cutting off other branches. The trees 

 should be carefully gone over in late fall or early winter, but any 

 time before the trees bloom will do. 



A Dry Season decreases the yield of potatoes, but increases the 

 starch content. A wet season has the opposite effect. 



