97 



I'lums. fiomrstic. may be expected to come into bearing the 

 5th year, dependent on the variety. 



riutns. Japanese, may be expected to come into bearing the 

 ear, dependent on thv 



In each class there i^ xme variation between the several 

 varieties. 



DIE BACK CAUSED BY SOUR SAP. 



This is a disease which we have noticed to be prevalent all 

 over South Africa, growers from time to time in different places 

 calling our attention to the same and asking its cause and cure. 

 The remarks below, by Leonard Coates, of California, can be 

 literally applied by us, the disease showing itself in the same man- 

 ner, and ending in the same result. We have occasionally seen 

 very serious loss from this cause in this country, our springs here 

 being very uncertain, naturally giving such results. 



" Early spring orchardists should not forget to examine their 

 cherry, prune, and plum trees for signs of ' gumming ' and other 

 diseases in the bark. Cherry trees will generally give evidence of 

 the ailment by the exuding of gum, although it frequently hap- 

 pens that a fermentation of sap has been going on for some time, 

 thus decaying the cambium layer for a space of it, it may be, a 

 foot or more before the evil is discovered. Sometimes a branch 

 is nearly if not quite circled, and unless the trees are carefully 

 watched they will suddenly die. because the bark is all dead at 

 some point, sufficient to prevent the flow of sap. It is only the 

 practised eye that can readily detect this disease unless the gum 

 shows on the outside. Let the trees, then, be closely watched at 

 this time, and for the next, month or two, and an occasional 

 incision may be made with a knife to ascertain the state of the 

 bark. All gumming or discoloured spots should be cut out clean, 

 and the exposed wood, when dry, waxed over or shaded. Such 

 places should be covered with wax. but to do everything when 

 it should be done, and how it should be done in an orchard is 

 not always possible: cut out the gum at all events, as that if 

 done in time will save the tree. 



With the plum and prune this disease develops somewhat 

 different symptoms, and is more difficult to control because less 

 apparent to the inexperienced grower, and many grown gray in 

 hy their trees die. A dark. " dead " ap- 

 pearance of the bark, often forming a slight depression, and, if 

 the tree be moderately \ a cracking of the bark, and 



\udation of gum. are all symptoms which, either one or all, 

 require prompt treatment. This treatment is simply to cut out 

 all dead or diseased bark, which should be done cleanly and 

 neatly, and wax or paint the exposed wood. 



