210 



THE GARDENER'S ASSISTANT. 



by an exudation of the sap from a rent in the 

 bark arising from accidental wounds, unskilful 

 pruning v or from the breakage of a branch. It 

 sometimes occurs in consequence of too many 

 branches being made to originate very closely 

 together on the stem, and not unfrequently 

 results from the tree having been worked on 

 an unsuitable stock, or planted in too rich soil. 

 In the latter case the obvious remedy is to take 

 up the tree and replant it in a poorer soil; but 

 if this cannot be done, root pruning, which by 

 limiting the supply of nourishment obtained by 

 the roots will diminish the flow of sap, may be 

 advantageously adopted with the view of check- 

 ing the disease; but above all, vicissitudes of 

 dryness and moisture at the roots should be 

 prevented. 



" A leaf disease of Cherries has lately been 

 reported from several orchards in the county 

 of Kent. In the early summer it affects the 

 leaves and fruit simultaneously, rendering the 

 latter unfit for market. In autumn and winter 

 its presence is easily detected. The diseased 

 leaves remain attached to the branches as if 

 the tree had been killed in the full vigour of 

 growth, just as the withered leaves remain on 

 a branch that has been severed from the stem. 

 The fall of the leaf in autumn is a normal pro- 

 cess carried out by the living leaf, which forms 

 at the point of its attachment to the branch 

 a cicatrix that secures when completed the easy 

 severance of the leaf from the branch, leaving 

 a clear scar. The speedy and fatal injury to 

 the leaf caused by the fungus prevents the 

 formation of this cicatrix, and the leaf remains 

 attached to the tree, showing in black spots the 

 fruits of the fungus. 



" A further striking characteristic of this 

 disease is the shortening of the branches which 

 bear the diseased leaves. The internodes or 

 joints between the leaves of these branches have 

 not been developed. The year's growth, which 

 should have extended to a considerable length, 

 measures less than an inch. The crowded leaf 

 bases have each a healthy bud in the axil. 

 The dwarfing of the branch is not due to any 

 attack from a fungus, for no fungus is present 

 in the tissues. The dwarfing is entirely due 

 to the want of food, consequent on the early 

 death of the leaf. That this is the case is con- 

 firmed by the fact that some of the dwarfed 

 branches have produced in the following year 

 vigorous normal shoots. 



" The disease has been spreading rapidly in 

 Kent during the last few years. The varieties 

 of Cherry-trees that have been reported as 



specially liable are Waterloo, Bigarreau, Frog- 

 more, Napoleon, Black Hearts, Clusters, and 

 Eltons. Turks and Governor Woods have not 

 as yet suffered much, and English and Flemish 

 Reds and May Dukes have not been attacked, 

 though odd trees of other varieties, such as 

 Bigarreau, growing among them have been 

 diseased. In one orchard the disease attacked 

 Waterloo first, soon spreading to other kinds, 

 while at another place this variety had not 

 been affected until last year, and then only 

 the leaves nad suffered, the fruit had not been 

 damaged. 



" Professor Frank, of Berlin, has described a 

 serious injury to Cherry-trees which, there is 

 little doubt, is the same as the disease that has 

 attacked the Cherry orchards in Kent. The 

 malady was first observed in the Cherry orchards 

 of the Altenland on the lower Elbe in Germany 

 about the year 1880. The diseased leaves re- 

 main on the tree all winter, and are intermixed 

 with the new foliage of the following season. 

 In spring he found on the dead leaves a fungus 

 fruit that had not been present on them in 

 autumn, a perithecium round at the base, about 

 one-twelfth of an inch in diameter, tapering up 

 into a pointed beak that projects from the 

 under surface of the leaf. These perithecia 

 contain the spores that re -infect the young 

 leaves and fruit. The fungus had already been 

 described by Auerswald under the name of 

 Gnomonia erythrostoma. Frank traces the rapid 

 spread of the disease in the Altenland to the 

 overcrowding of fruit-trees and to the presence 

 of open ditches in the neighbourhood of the 

 orchards causing too much moisture, and so 

 presenting conditions favouring the growth of 

 parasitic fungi. While such adverse conditions 

 should be remedied, he recommends, as the only 

 method of stamping out the disease, the gather- 

 ing and burning of all diseased leaves, which, 

 he considers, need not be attended with more 

 difficulty than the yearly harvesting of the 

 fruit. It is very important that Cherry growers 

 should at once be made acquainted with the 

 cause of the injury to the orchards and the 

 remedy recommended by Frank, which is the 

 destruction of the dead leaves. To be efficient 

 this collecting and burning of the dead leaves 

 must not be done in a solitary orchard here and 

 there, but must be carried out throughout 

 Kent." — (Carruthers in the Report of the Royal 

 Agricultural Society, 1900.) 



Insects, &c. — See chapter on this subject. 

 Bark Enemies — Wceberian Tortrix. Fruit and 

 Seed Enemies — Birds. Leaf Enemies— Cherry 



