PRUXK 



PRUNE 



2815 



Some growers think that on extremely rich soils, 25 

 feet is a more desirable distance. 



The tillage given prunes is very similar to that for 

 other deciduous fruits grown in the Northwest. In all 

 young orchards, the tillage should be very thorough 

 in the early spring. With trees not in bearing, tillage 

 should cease by the middle of July. In many of the 

 bearing orchards, where the tillage has been very 

 thorough in the early spring months, sufficient vigor of 

 tree and size of fruit is often obtained so that tillage 

 may be discontinued by the middle of July or the first 

 of August, but in many of the orchards it will be neces- 

 sary to continue the tillage up to about the time of 

 harvest, which comes later, varying from the first of 

 August to the middle of September. 



Formerly, the trees were all headed from 30 to 40 

 inches in height. In more recent years, however, many 

 growers are heading from 20 to 24 inches and produ- 

 cing very satisfactory trees. The same general principles 

 that apply to the pruning of apple trees, also apply to 

 the prune. Care should be taken to have the main 

 scaffold limbs spaced as far apart as possible. Strong 

 heading back is necessary the first few years. With 

 many orchards, summer pruning can be conducted 

 advantageously, the pruning being done largely in 

 June and consisting of a cutting back of the 

 terminals to the point where it is desirable to 

 force out new laterals. Occasionally a little 

 thinning out of the laterals is practised. 

 When the trees reach their heavy bearing, 

 which is about the seventh year, it is desir- 

 able to give them moderate pruning annually, 

 the aim being to keep the trees well supplied 

 with strong one- and two-year-old wood, as 

 the large plums are found almost invariably 

 on the vigorous wood. When orchards have 

 been allowed to run down somewhat, it is 

 often found desirable to thin out the spurs 

 with hand shears, and in this way reinvigo- 

 rate the remaining spurs. When trees are 

 very much run down, the most satisfactory 

 treatment will probably be to dehorn them, 

 forcing out a new vigorous top which, in three 

 to four years, will produce commercial crops 

 of fruit. Very little hand-thinning is done with 

 plums and prunes in the Pacific Northwest. 

 The Italian prunes generally thin themselves. 

 Some varieties of plums, however, must have 

 hand-thinning. 



Very little work has been done as yet with manures 

 or fertilizers. Commercial fertilizers, where tried, have 

 never given striking results in the older orchards. The 

 growers are finding that, in mature orchards, a stable 

 compost is very desirable. When it is impossible to 

 secure such material, vetch or rye planted the latter 

 part of August or early September, and plowed under 

 in the early spring, is very beneficial. Care has to be 

 taken, however, not to use excessive amounts of nitro- 

 gen, as this element tends to make the trees unpro- 

 ductive, and generally makes the skin of the prune so 

 heavy that it is difficult to evaporate. 



The prune industry in the Pacific Northwest is not 

 old enough as yet to demonstrate how long an orchard 

 will remain profitable. However, there are several 

 orchards in Oregon forty years old, that are still very 

 .productive. On the other hand, there are orchards 

 twenty years of age that have passed their usefulness. 

 The trees in this latter class, however, have been 

 neglected. Where good soil is obtained, and proper 

 care given, it is safe to say that the orchards will be 

 productive at least fifty years. 



There are a number of insects which are troublesome 

 to the prune. The San Jose scale attacks the tree, but is 

 very easily controlled with the lime-sulfur spray. The 

 borers both the peach-root (Sanninoidfa opdlescens) 

 and the shot-hole (Xykborus dispar) are very bad. 



Young trees are often severely attacked with aphis. 

 Other insects which are more or less troublesome at 

 times are the leaf syneta (Synela albida), the Indian 

 meal moth (Plodia interpunctella) , the rose-leaf hopper 

 (Empoa rosie), and the tipulid (Ctenophora angusti- 

 pennis). Of the other diseases, the mushroom root-rot 

 (Armillaria mellea) is very serious, especially when the 

 trees have been planted on newly cleared land. Brown- 

 rot (Sderotina fructigena) is the worst pest of the fruit 

 and is becoming more serious. Other diseases that 

 have to be contended with are crown-gall, rust, and 

 bacterial canker. The latter three diseases, however, 

 are not nearly so serious as the first two mentioned. 



Of the varieties of prunes that are grown in Oregon, 

 the Italian (Fellenberg) comprises about seven-eighths 

 of the planting, and the percentage in favor of the 

 Italian is constantly increasing. For evaporation, it is 

 the only one worth consideration in the Northwest. 

 For shipping purposes, however, numerous plantings 

 have been made of the Tragedy, and also of the Hun- 

 garian. Other varieties that are grown to a limited 

 extent are the French, locally called the Petite, or Prune 

 d'Agen, the Pacific, Willamette, Clairac Mammoth, 

 Columbia, Tennant, Silver, and Sugar. There is, of 

 course, to be found scattered over the Northwest a 



3197. A prone orchard in Oregon, with the fruit on the ground 

 ready for harvest. 



miscellaneous list of soft plums that are grown largely 

 as local fruit. Since the Italian prune is benefited 

 by growing with other varieties, there will probably 

 always be a scattering of other kinds planted in our 

 orchards. Many growers report that, wherever the 

 Italians are near other varieties, a more satisfactory 

 set of fruit is obtained on the Italian. In the evaporated 

 fruit districts, the Petite will be the pollinator. The 

 greatest drawback of this prune is its small size. It, 

 however, dries heavier than the Italian and, size for 

 size, sells somewhat higher. 



When prunes are to be shipped in their green state 

 for eating fresh in the eastern markets, it is customary to 

 pick the fruit while it is still very hard and green. The 

 plums, however, will have developed to a very large 

 extent their true color before the packing is undertaken. 

 The fruits are graded carefully and packed in five- 

 pound baskets, four baskets being placed in a crate. 

 While this crate virtually holds about twenty pounds, 

 the weight of the fruit will range from eighteen to 

 thirty pounds, according to varieties, size, and the 

 general condition of the fruit. These four-basket car- 

 riers are the typical ones used for plums, apricots, and 

 vinifera grapes constantly seen in the eastern markets. 

 The fruit, when properly refrigerated, has not only 

 been shipped all over the United States, but successful 

 shipments have also been made to Europe, Mexico, 



