1378 
PLUM 
plow-in with the oeginning of tillage in March; for no 
summer-growing crop can be allowed in the orchard. 
The matter has been under investigation at the Califor- 
nia Experiment Station for some years, and after many 
trials of native and exotic legumes, three species of 
European lupins [L. pilosus, var. roseus and var. 
L 1858. fruit-spurs left; a 
domestica plum. The letters indicate the termination of annual 
growths. (see page 1374.) p. angustifolia on the right. (See page 1374.) 
caeruleus, l. angustifolius), and the "hairy vetch "( t'icia 
villosa ) have been found to be the most promising. From 
numerous analyses of California soils, Professor Hil- 
gard has found them generally well supplied with lime 
and potash, with nitrogen and phosphoric acid not over- 
abundant. It is, then, these latter which will have to be 
supplied first, and such has been the advice given to 
growers. 
As mentioned above, the Plum has few serious ene- 
mies in California, and none which cannot be held in 
check by spraying and other treatment. upon the leaves 
the Plum aphis and the canker worm have given some 
trouble. Lately, the "peach moth" has been found at 
work on the prune trees, but not to any serious extent. 
The trees, too, are sometimes subject to the attacks of 
scale insects; the black scale (lecanium olea) , apricot 
scale (L. armeniacum), frosted scale (l. pruinosum) 
and pernicious scale (aspidiotus perniciosus) being the 
most frequent; all of which, however, the California 
fruit-grower has learned to keep in check, and in some 
cases even to eradicate. The crown root-knot has also 
caused considerable trouble. The cause of this disease 
has been lately demonstrated by Toumey to be a "slime 
mold" (dendrophagus globosus). Relief has been se- 
cured by cutting off the knots and painting the wounds 
with Bordeaux mixture. 
In California some fruit is usually borne the third 
year; in the fourth a fairly profitable crop is expected; 
the fifth from 50 to 60 pounds per tree should be pro- 
PLUM 
duced, which ought to double in the sixth, and after 
that from 150 to 300 pounds is the rule. These figures 
apply mostly to the prunes; many of the Plums are two 
or three years later in coming into full bearing. From 
200 to 300 pounds are considered the average at full bear- 
ing in the Santa Clara valley. In some instances 600 and 
even 800 pounds have been produced, and a 6-year-old 
tree at Visalia (San Joaquin valley) is credited with 
1,102 pounds of fruit in one season. 
It would be impossible to enumerate a full list of the 
varieties actually in successful cultivation within the 
state. Such a list would probably include every note- 
worthy variety of Domestica Plum. Many, however, 
despite excellence of quality and flavor," are suited 
only for home-growing, or at most for local markets, on 
account of poor shipping qualities. For this reason 
the number of varieties planted on a large scale is 
being constantly reduced. 
Experience has demonstrated the superiority of some 
varieties for certain climatic regions and general market 
conditions, and these have come to be recognized as 
standard. At the head of the list stands the prune d'agen, the originally introduced has proved itself adapted to more 
varying conditions 
jk-rhaps the 
1 the state. 
For some time its identity as the true French prune was 
disputed; but from authentic samples submitted to 
them. French experts have declared it to be of the 
true d'ente type of the Agen district, both in botanical 
characters and in sweetness and flavor. It is, of course, 
used chiefly for curing. In the same category belong 
the robe de Sergeant, Imperial Epineuse, Silver and 
sugar-all standard drying prune varieties. The Robe 
de Sergeant has been supposed by some to be a syno- 
nym of the Prune d'Agen, and is so considered in 
France; but in California it is grown as a distinct va- 
riety. The fruit is larger, usually more highly flavored, 
and has commanded higher prices in the San Francisco 
market. The tree, however, has not proved so widely 
adaptable, and is in disfavor in the coast valleys on 
account of defective bearing; in the interior it is more 
satisfactory. The Silver prune (an Oregon seedling of 
Coe Golden Drop) is also a defective bearer in some 
districts, and is used mostly in the preparation of 
"bleached prunes," for which it has proved quite profit- 
able in some instances. It is sometimes marketed in 
the fresh state ;li^o. The Imperial epineuse is a recently 
introduced french variety and is fast becoming very 
popular. so far as tried it has proved very profitable, 
especially in the Santa Clara valley, where many or- 
chards have been grafted over to it." The fruit is very 
large and handsome, and actual analysis has shown it 
to contain 2 
sugar 
than the ordinary French. It 
must be distinguished, how- 
ever, from the "Imperial," a va- 
riety very much inferior in 
flavor and sweetness and not 
nearly so satisfactory. Luther 
Burbank's new Sugar prune 
(introduced two years ago) 
bases its claims upon superior 
sweetness and flavor, together 
with fair medium size. It has 
not yet been long enough under 
trial, however, to justify any 
remarks regarding its merits as 
a commercial variety. The Ger- 
man prune, italian( fellenberg) , 
Golden prune, Hungarian 
(Pond Seedling), and Tragedy 
are varieties sometimes used for 
curing, but are frequently 
shipped green as "Plums." Of 
these the German is perhaps 
the most extensively used. The 
Italian succeeds well along the 
coast in places liable to fogs 
or sea winds, where the French is not at its best. 
It is valuable as a late variety, and is said to dry 
excellently, as does also the Golden, an Oregon seed- 
ling. The fruit of the Hungarian (Pond) is very hand- 
