360 STATE BOARD OF AGRICULTURE. 



PEAli-BLlGIIT. I'IRE-BLIGHT, TWIG-BLIGIIT. 



(Bacillus amylovorus Burrill.) 



This disease is known to he of bacterial origin. It attacks the young, tender 

 growth of apple, quince and pear and has also been recorded as attacking rasp- 

 berry and blackberry shoots. Paddock, in a recent bulletin, describes a blight 

 of apricots which also proves to be due to the same organism. Its worst effects, 

 however, are seen on the pear. Its first appearance is indicated by the killing 

 of the leaves at the ends of growing shoots, the leaves often presenting the ap- 

 pearance of having been scorched. The shoot is also affected and like the leaves 

 may become blackened, the young wood and inner bark being much darkened. 

 The disease progresses rapidly backward into the branches and in time may kill 

 the entire tree. Small drops of a gummy liquid often ooze out of ruptures in the 

 bark of the young affected shoots and this liquid contains myriads of the micro- 

 scopic bacteria which are the cause of this blight. Bees and other insects often feed 

 on this material and when they subsequently visit the flowers some of the germs 

 of the disease may be deposited on the stigmas, thus introducing them into the 

 tissues of the tree at these points. The bacteria also gain an entrance through 

 wounds or insect punctures but are unable to enter the uninjured stems or 

 leaves. 



The rapid progress of the disease calls for immediate attention in order to 

 prevent the great damage of which it is capable. So far no remedy has been 

 found to prevent or cure the blight on an affected tree by means of spraying. 

 The only effective measure seems to be the removal of the affected branches, 

 cutting far enough below the limits of the disease to remove all the bacteria 

 from the limb. Thus it is best to cut the branch off at least three or four inches 

 below the lower limits of the disease, the removed branches being burned. This 

 pruning should be done whenever the disease appears and a thorough removal of 

 every affected branch during autumn is especially recommended, as the disease 

 may otherwise pass the winter in the wood and appear the following spring. 

 The fire-blight does not seem to prove as fatal to the apple tree as to the pear, 

 in fact apple trees often outlive the attacks of this parasite. It is most de- 

 structive in the case of rapidly growing trees in which the wood is soft and 

 watery, hence conditions which favor a slower and firmer growth tend to prevent 

 or check the disease. 



QtnXCE DISEASES. 



The quince which is closely related to the pear and the apple is also subject 

 ta some of the same diseases as those fruits. 



FiBE-BLiGiiT. (See on Pear.) 



This disease is not uncommon on the quince and in severe cases kills nearly all 

 of the new growth. The leaves become uniformly brown or black, this character 

 distinguishing the disease from the leaf blight-fungus which causes spotting of 

 the foliage. The same vigorous treatment is needed here as in the case of the 

 pear, namely, — cutting off and burning all affected branches, care being taken to 

 cut below the diseased portion. 



LEAF-BLIOIIT, FRUIT SPOT. 



(Entomosporium maculatum Lev.) (See on Pear.) 



This is the most common disease of a fungous nature which affects the quince. 

 Its appearance on the leaves and fruit is similar to that on the pear. In severe 

 cases it causes the premature falling of the foliage thus checking the normal 

 development of the fruit. 



Treatment is the same as for pear. 



QUINCE BUST. 



(Gymnosporangium aurantiaca Pk.) 



The Quince Rust, also known as the orange rust of the quince, attacks the 

 stems and young fruit causing swollen orange colored spots from which protrude 

 small cylindrical processes. These tubular outgrowths are filled with dust-like 



