70 MISSOURI STATE HORTICULTURAL SOCIETY. 



Whenever a vineyard is attacked by mildew, the leaves should be 

 carefulljT^ gathered and buried. 



The grape rot^ which has committed such ravages in the Western 

 vineyards, has thus far baffled all the efforts of horticulturists to re- 

 strain it. By placing the bunches in small paper sacks so on after the 

 berries have set, the spore swill be prevented from developing, and a 

 crop can be secured. 



When the vines are trained upon trellf^es, if two boards are nailed 

 together at an oblique angle, and fastened to the tops of the posts so as 

 to form a roof over the row, the radiation of heat will be checked and 

 the rot will not appear. 



The so-called plum disease, in which the fruit developes into an 

 empty pod, is the work of a fungus known as Exoascus pruni. 



The black knot, which in some localities has proved so destructive 

 to the plum and cherry, is caused by a parasite called Sph(je,ria morhosa. 

 The diseased wood should be cut away, as soon as discovered, at a 

 point at least a foot below the lowest point attacked. The branch 

 should be burned, and the knife or saw used should be carefully cleaned 

 before it is used upon another tree. 



HhQ pear JZ^'^-A^ has been terribly destructive to the orchards of 

 the country, but no sure remedy has yet been discovered. 



In discussing this disease great confusion often arises from the fact 

 that there are three or four diseases which are known by the general 

 name of pear blight. 



One form is the leaf hlight which attacks pear seedlings, and pear 

 trees growing in exhausted soils. This is generally caused by a fungus 

 growth, but in seasons when the weather is unfavorable to fungoid de- 

 velopment, the same result, ^. e,, the dropping of the leaves and the 

 cessation of growth, is produced by aphides and red spiders. 



The twig hlight attacks the new shoots of the apple and quince, as 

 well as of the pear, and is generally caused by a fungus. The infected 

 branches should be cut off and burned. 



The form of blight which is most destructive is known as frozen 

 sap hlight^ and also as fire hlight. It makes itself manifest dunng the 

 growing season, and unless it is checked will destroy the tree. 



Until recently the cause of the disease has been a matter of theory 

 and speculation, but thanks to the microscope and Prof. Burrill, of Il- 

 linois, a flood of light has been poured upon the subject. If a drop of 

 of sap from a diseased tree be examined with a microscope under a 

 magnifying power of 1,000 diameters, it will be found to swarm with 

 bacteria. * 



