EXPERIMENT STATION BULLETINS. '177 



development of the leaves and in that condition the spores of the fungus, 

 which is the cause of the disease, readily gain access to the interior of the 

 leaves. It is known that the spores and mycelium of the fungus winter 

 upon the twigs, and if they can be destroyed the danger of the attack to 

 the foliage will be greatly lessened. While the ordinary solution of cop- 

 per sulphate, (one pound in fifteen gallons of water) is effectual in de- 

 stroying these spores, better results are obtained with Bordeaux Mixture 

 that contains a large excess of lime (five pounds of copper sulphate, ten 

 pounds of lime and fifty gallons of water). If this is thoroughly sprayed 

 over the trees, before the buds open, covering every portion of the trunk 

 and branches, it will greatly lessen the danger of an attack to the foliage. 

 As soon as the blossoms have fallen, a second application with the same 

 mixture should be made and, if the weather is favorable to the disease, 

 this should be repeated at the end of ten days or two weeks. Experiments 

 for the last four years have shown that if the trees are sprayed as above 

 recommended, there will be but little trouble from the disease. To be 

 effectual, however, the spraying must be very thorough and must be 

 done at the right time. Certain varieties, like Elberta, are much more 

 injured than others, owing to the peculiarities in the growth and texture 

 of the foliage, and when we have a variety that is little, if any, injured 

 by the disease, it should be preferred in planting to others that are sub- 

 ject to the disease, providing they are of an equally valuable variety. As 

 some of our best varieties are very subject to the disease, he should make 

 use of the spraying mixtures who attempts to grow them. 



CROWN GALL. 



Many of the peach trees that have been brought into Michigan from 

 Ohio and Maryland have shown upon their roots swellings of various 

 sizes to which the name of " Crown Gall," has been given. These are 

 most commonly found at or near the collar of the trees, but detached 

 swellings. have often been found upon the smaller roots. When upon 

 large roots, or at the collar, the tree will be of little value and should 

 never be planted, as, even if it lives, the growth will be unsatisfactory. 

 The real nature of this trouble is not understood, but, even though it has 

 not been definitely shown to be contagious, the trees should be regarded 

 with suspicion. The swellings most generally appear in the nursery, and 

 are most common when the trees have been grown in moist soil, espe- 

 cially if it contains a large amount of decaying organic matter. In case 

 a tree growing in the orchard has been destroyed with crown gall, it will 

 be safest to remove the soil and replace it with fresh materials before 

 planting another tree. While it cannot be regarded as absolutely sure, 

 it is possible that where there are but one or two small swellings, upon 

 the smaller roots, the tree can be saved by cutting off the roots as far 

 from the swellings as possible. 



Care should be taken both by nurserymen and orchardists, in planting 

 trees in wet soil, especially if the land contains a large amount of organic 

 matter. Instances have been known where the disease was very trouble- 

 some on soils heavily enriched with stable manure, or where large 

 amounts of saw-dnst have been worked into the soil; also where raspberry 

 plantations have been removed. Similar " galls " have been found on the 



