PLUM 



PLUM 



2717 



Plum trees are usually planted when two years old 

 from the bud, although some of the strong-growing 

 kinds may be planted at a year old with the very best 

 results. As a rule, all plum trees are planted about as 

 far apart as are peaches, that is, from 15 to 20 feet 

 each way. Many growers prefer to plant them closer 

 one way than the other and eventually to stop culti- 

 vation in one direction. If this system is used, they 



3071. Early Red, one of the Russian plums. (X%) 



may be placed 18 or 20 feet apart one way, and 8 to 12 

 feet the other way. When planted, the trees are pruned 

 in essentially the same way as apple trees. It is usually 

 advisable to start tops as low as possible and yet allow 

 of the working of the cureulio-catcher or other tools 

 below them. This means that the limbs should start 

 from 3 to 4 feet above the ground. With the modern 

 implements and methods of tillage, there is little incon- 

 venience in working the land if tops are started as low 

 as this. The subsequent pruning of the plum tree has 

 no special difficulties. About four or five main limbs are 

 allowed to form the framework of the top, and in most 

 varieties, especially those which are not very tall 

 growers, the central trunk or leader may be allowed to 

 remain. The fruit of the domesticas is borne mostly 

 on spurs, as shown in Fig. 3078. These spurs, there- 

 fore, should not be removed unless it is desired to thin 

 the fruit. In the americanas and the Japanese varie- 

 ties, the fruit is borne both on f^urs and on the annual 

 axial growth. 



Insects and diseases. The black-knot is one of the 

 most serious plum diseases. It is best kept in check by 

 systematically cutting it out (several inches below the 

 swelling) and burning it. The grower should go over 

 his orchard for it in the summer and again as soon as 

 the leaves fall. If trees are thoroughly sprayed every 

 year with self-boiled lime-sulfur or bordeaux mixture 

 for the leaf-blight fungus, the black-knot will make 

 comparatively little headway in the orchard. 



The blight, which causes the leaves to fall in August 

 or September, is a damaging disease; but it can readily 

 be kept in check by thorough spraying with self -boiled 

 lime-sulfur or bordeaux mixture two or three times 

 during the summer. The mixture for spraying plums 

 should be weaker than for apples, particularly for the 

 Japanese varieties. 



The fruit-rot is the work of a fungus. Many times 

 the dead and dried fruit may be seen hanging on the 

 tree all winter, as shown in Fig. 3079; and in such cases 

 it is very likely that the fruit-spur may be killed, as the 

 upper one in the picture has been. In handling this dis- 

 ease, the first consideration is the fact that some varie- 

 ties are much more susceptible to it than others. The 

 Lombard is one of the worst. Again, if the fruit grows 

 in dense clusters, the disease is more likely to be severe. 

 The thinning of the fruit, therefore, is one of the best 

 preventives of the spread of the disease, and at the 

 same time, also, one of the most efficient means of 

 increasing the size, quality, and salableness of the prod- 

 uct. Thorough spraying with self -boiled lime-sulfur 



is a specific for the trouble and helpful in related 

 troubles or diseases. 



The curculio, which causes wormy fruit, can be held 

 in check by the process described under Peach. 

 Formerly, jarring the beetles on sheets or curculio- 

 catchers (a wheelbarrow-like device with a large cloth 

 hopper) was the prevailing practice with those who 

 gave extra care to their fruit, and this method is 

 still recommendable to amateurs and small planta- 

 tions; but with the modern good tillage and the prac- 

 tice of keeping all parts of the plantation and the 

 hedge-rows clean, and with the introduction of more 

 effective spraying, the curculio is found to do much less 

 damage and usually to be held sufficiently in check. 

 Practising open pruning to let in the sun, and raking 

 the dropped fruit out into the sun will also check the 

 breeding. How far spraying with arsenicals will con- 

 trol the curculio on plums is not yet well understood, 

 but growers usually feel that it is a distinct aid. To the 

 bordeaux mixture or to self-boiled lime-sulfur, two 

 and one-half pounds of arsenate of lead may be used to 

 the fifty gallons, in one spraying soon after the petals 

 drop, and another a week or ten davs later. 



L. H. B. 

 Native American plums. 



Approximately 300 varieties of plums, derived chiefly 

 from six native types, have been named, described, and 

 introduced by American nurserymen and have found 

 their way into American orchards and American 

 pomological literature. The major part of this inter- 

 esting development came in response to the urgent 

 demand, most manifest in the years from 1870 to 1900, 

 for the disco very of new types of garden fruits suited 

 to the peculiar conditions of the middle western prairie 

 states. Outside this area, the native American plums 

 made much less impression, and while they have been 

 widely tried, they have been generally discarded. Even 

 in the area to which they are native and in which the 

 need for them is greatest, they do not now play an 

 exclusive role. A large part of the named varieties 

 introduced by the nurserymen have already been lost 

 to American horticulture. A creditable minority of 

 these varieties, however, have qualities of absolute 

 and considerable merit, and may be looked on as per- 

 manent additions to pur pomological wealth. The 

 native varieties are still propagated and planted by 

 thousands annually, both for home use and for market. 

 For certain culinary purposes, many of the natives are 

 superior; and in many places, particularly in states of 

 middle latitude, they are the most profitable market 

 plums grown. 



The americana plums are especially qualified to with- 

 stand the severity of northern winters. They are super- 

 latively hardy. They are practically the only plums 



3072. Voronesh Yellow, a Russian plum of somewhat recent 

 introduction. (X?i) 



