2716 



PLUM 



PLUM 



be thrown into five general groups, although any classi- 

 fication is arbitrary at certain points: 



1. Prunes, characterized by sweet firm flesh, and 

 capable of making a commercial dried product. They 

 may be of any color, although blue-purple prunes are 

 best known. Some of the prunes are grown in the East 

 as ordinary market plums, being sold in the fresh state. 

 Almost any plum can be made into dried prunes, but 

 the varieties used commercially for this purpose con- 

 stitute a more or less distinct class of sweet and thick- 

 fleshed kinds (see definition, page 2719). In the East, 

 prune is nothing more than a varietal name. 



2. Damsons, comprising very small firm plums of 

 various colors, usually borne in clusters, the leaves 

 mostly small. The run-wild plums of old roadsides 

 and farmyards are mostly of the general damson type 

 (Fig. 3070). 



3. The green gages, comprising various small green 

 or yellow-green plums, of spherical form and mostly 

 of high quality. Reine Claude is the commonest 



3070. Damson plum. ( X H) 



representative of this group in the East. The name 

 green gage often stands for a group rather than for a 

 variety. 



4. Large yellow plums, such as Coe Golden Drop, 

 Washington, and the like. 



5. Large colored plums, including the various red, 

 blue, and purple varieties, like the blue prunes, Lom- 

 bard, Bradshaw, Quackenboss, and the like. 



The Japanese plums (Prunus salidnd) differ from 

 the domesticas in having longer thinner smooth and 

 mostly shining leaves, smooth twigs, a greater tendency 

 to the production of lateral fruit-buds on the annual 

 growth, and mostly rounder or shorter fruits with col- 

 ors running more to cherry-reds and light yellows. 

 Most of the varieties are as hardy as the domestica 

 series. The Japanese varieties are important because 

 they add variety to the list, and especially because they 

 are rich in very early kinds, and the fruit is usually so 

 firm that it carries well; aside from this, the trees are 

 vigorous and very productive, and the species is less 

 liable to injuries from black-knot and curculio than the 

 domesticas. 



The native plums, chiefly offspring of Prunus ameri- 

 cana, P. nigra, P. angustifolia, P. Munsoniana, and P. 

 hortulana represent a wide range of varieties. Those 

 from Prunus americana and P. nigra parentage are very 

 hardy and are adapted to regions in which the domestica 

 and Japanese types are tender, as in northern New 

 England, parts of Canada, and the northern plains 

 states. Those partaking strongly of P. angustifolia 

 parentage, and the greater part of the hortulanas, 

 thrive well in the South, where the climate is too con- 



tinuously hot for other plums or where the fruit-rot 

 fungus is too prevalent. 



The domestica varieties are mostly fertile with them- 

 selves, but the natives usually bear best in mixed plant- 

 ing so that pollination is assured. See Pollination. The 

 Japanese varieties also usually profit by mixed plant- 

 ing. How far failure to set fruit is due in general to 

 lack of pollination and how far to other causes, is yet 

 largely to be worked out. 



Plum-growing. 



The plum thrives on a variety of soils. The domesticaa 

 commonly do best when planted in clay loam. They 

 usually thrive well on lands which are suited to pears, 

 or on the heavier lands to which apples are adapted. 

 Yet many varieties grow well on lands that are com- 

 paratively light or even almost sandy, with good care. 

 The americanas thrive best in a rather moist soil, and 

 mulching is often very favorable to the size and 

 quality of the fruit. 



The stocks upon which plums are grown 

 are various. By far the greater number of 

 the trees in the North are now grown on 

 Myrobalan, which is a species of rather 

 slow-growing plum (Prunus cerasifera), 

 native to southeastern Europe and south- 

 western Asia. This is the stock some- 

 times recommended in the older fruit- 

 books for the making of dwarf trees; but 

 unless the top is kept well headed in, the 

 trees generally make normal growth upon 

 it. Trees grown on this root are usually 

 larger and finer at one or two years of age 

 than those grown on other plum stocks, 

 and the probability is that they are nearly 

 as useful from the grower's standpoint as 

 any other. However, there are some varie- 

 ties that overgrow the Myrobalan, and 

 the stock is likely to sprout from the 

 ground and thereby cause trouble. The 

 Myrobalan is variable from seed, and this 

 fact may account for some of the unsatis- 

 factory results now and then reported. 

 St. Julien is perhaps a better stock, but is 

 more expensive to import and less readily budded. The 

 Myrobalan and St. Julien stocks are imported. 



Probably the best stock for domesticas, from the 

 standpoint of the grower, is the domestica itself, but 

 seeds of it are more difficult to secure, the stock is more 

 variable and it is more likely to be injured in the nur- 

 sery row by leaf -fungi; therefore, as a matter of practice, 

 the Myrobalan has very generally supplanted it. In the 

 middle and southern states the peach is largely used as 

 a stock upon which to grow plums, and it seems to 

 be gaining favor in the North. It is undoubtedly a 

 very excellent stock for sandy lands, and, in fact, 

 is probably better for such lands than the Myrobalan 

 itself. Some varieties of which Lombard and French 

 Damson are examples do not take well on the 

 peach. The Japanese plums are commonly worked 

 on the peach. The Marianna stock, which is much 

 recommended in the South, has not found favor 

 in the North. Some varieties of plums are such 

 slow and crooked growers in the nursery that it is 

 advisable to top-graft or bud them on some strong and 

 straight stock. The Lombard is no doubt the most 

 adaptable stock for this purpose now grown by nursery- 

 men. The old Union Purple is one of the best stocks, but 

 is not much grown at present. Reine Claude, German 

 Prune, and Copper are probably best when top-worked 

 on some strong stock. For many native varieties, seed- 

 lings of vigorous natives, as of Golden Beauty and 

 Wayland, make excellent stocks. Americanas should be 

 worked on their own seedlings, at least in the North. 

 In the South they are often budded on Marianna. The 

 whole subject of plum stocks needs experimental study. 



