THE XIXETEEXTH ANNUAL MEETING. 



97 



Shot HoU 



ft [i/ricolOk 



u 





erally less than a tenth 

 of an inch in diameter. 

 Although the fungus can 

 be seen from either side, 

 it works principally in 

 the lower tissues of the 

 leaf. There the conidia 

 are developed and toward 

 spring brownish winter 

 spores will be formed, 

 which will 

 the new leaves 



germinate on 



as 



they 



W ht^tli M. »«■ at ' " 1 at 1 J 



Fig. 6. Shot-Hole Fuxfics {Septoria pruni) 

 From drawing by Stewart, class of '89, M. A. C. 



during May and June, many of the spores will be destroyed. 



The fallen leaves 



should be raked up and 



, , , burned, and if the trees 



plum leaf. ' _ 



are sprayed once or twice 



CONCLUSIONS. 



"Although the development of the various fungi, within the tissues of 

 the tree or fruit, is the real cause of the diseases just discussed, the con- 

 ditions under which the trees are growing will have much to do with the 

 amount of injury inflicted. A soil that is too wet or too dry, or that does 

 not furnish soluble food in proper proportions, will cause a derangement 

 of the vital functions of the plant and will both invite the attack of fungi 

 and permit them to ravage at their will. If these unfavorable conditions 

 can be changed, and the plant strengthened, it may be able to resist all 

 attacks of the fungi, or to so hold them in check that the injury will be 

 much reduced. The following treatment will then be seen to be a perfectly 

 rational one. 



"1. See that the land is properly drained, either naturally or artificially, 

 before the trees are j^lanted. 



"2. Try to retain a sufficient supply of moisture during the summer 

 droughts. This can l)est be secured by frequent shallow cultivation. 



"3. Provide a liberal amount of proper food for the trees. For all fruits, 

 and in fact for all plants, one of the best fertilizers is unleached wood 

 ashes. For bearing orchards these should be applied broadcast, early in 

 the spring, and plowed or harrowed in. Fifty bushels per acre will make 

 a wonderful difference; and if they can be cheaply obtained, three or four 

 times that quantity can be applied with profit. 



"•1. Thin the fruits so that they will not be in contact. This will pay of 

 itself in the increased size of the fruits that are left. It will lessen the 

 strain on the vitality of the tree, and in case rot sets in, its destructiveness 

 will be greatly reduced. 



" 5. In case a f ungus^of any kind appears, remember that it is a minute 

 plant which developes innumerable t[uantities of spores or seeds ; that they 

 are wafted about by the wind and will convey the disease to great distances, 

 destroying, if unmolested, not only the present crop but the orchard itself. 

 The following remedies then should be used on their first appearance: 



" a. Cut off and burn all diseased portions. 



''5. Spray the affected trees with some approved fungicide." 



13 



