There are two types of varieties, the European, that contain less water and more soluble solids, suitable to be dried, and the Japanese, more juicy for fresh consumption.

Some European varieties are thought to come from the Prunus domestica, a wild plum tree that grows near the Caspian Sea. Another wild ancestor of the European and South African varieties can be P. saliciana, in China and Japan. In addition, the Americans have used the wild plum P. subcordinata, from America, to cross with European plum or Asian varieties.

According to information of the Departmento de Cultivos Leñosos de la Escuela Universitaria de Ingeniería Técnica Agrícola (EUITA), Valencia, ( http://www.euita.upv.es ), in Spain the plum tree is mainly cultivated in Murcia, Comunidad Valenciana, Andalusia, Aragón, Catalonia and La Rioja. The most exported varieties are Reina Claudia , Santa Rosa and Golden Japan. Other cultivated varieties are Red Beauty , Formosa and Burbank.

We must distinguish between the European plum tree and the Japanese:

1- The European plum (Prunus domestica), usually bears pale green (" Claudias") or purple (" Prunas") fruits, to which dry plums belong, since they have a high content of soluble solids and contain little water; this makes dehydration much easier. The most used varieties for their industrial processing belong to the group Ente, like Agen of Ente GF 707. For instance, in Alicante and Castellón, the most cultivated varieties are Stanley, Claudias, Ana Spath, President and Giant.

Normally, this group is well adapted to regions with continental climate due to their flowering, greater demand of cold and less demanding in cares.

2- The Japanese plum (Prunus salicina), with earlier maturation and, in general, reddish and black epidermis, although some can be pale yellow, like " Golden Japan". Its water content is high, so it is very juicy. For instance, in the Rivera Alta of the Comunidad Valenciana (Spain), we find the varieties Red Beauty , Methley, Golden Japan , Formosa, Santa Rosa and Burbank. They are cultivated mainly in the warmest areas due to their flowering period, although in some cold areas we can see almond trees grafted with the variety Red Beauty, important for its pink-dark colour and its earliness.

The main plum producing countries are China, the United States, Rumania and Germany.

In the U.S.A., the most cultivated varieties are, in alphabetical order, Beauty (available from the end of May to the beginning of July), Burbank, Gaviota (June to August), Golden Japan (January to May and June to August), June Blood (end of June to the beginning of July), Kelsey and Ontario (July to September).

In Rumania, the variety Switzen or Quetsh, original from Asia and that is also produced in Germany, France and The Netherlands, is available in September and October.

In Germany, the varieties of greater diffusion are Czar (August), Ontario (July to September), Opal (August) and Switzen (September to October).

Some varieties of plums:

" Sungold"
It is a Japanese variety, whose fruit is big and aromatic and the skin is red when it matures. Yellow-orange and juicy flesh. South African variety that appears in the market in February and April.

"Red Beauty"
It is a variety of the Japanese plum, with the rounded fruit, medium thick calibre, considering that it is a very early variety. Red to dark red skin, depending on the maturity degree. Yellow flesh, hard texture and good flavour. It bears handling and transport. Very vigorous tree, open habit, self-sterile. The maturation period takes place from the end of May to the beginning of June. As an exception to the fact that Japanese plum is produced in the warmest areas, in the Ribera Alta (Comunidad Valenciana, Spain), predominate the Japanese early varieties, intended for export, like " Red Beauty" that is progressively replacing the varieties Methley, Golden Japan and Formosa.

" Golden Japan"
Thick, clear yellow fruit, thick and resistant bright skin, very juicy and pleasant pulp, belonging to the group of Japanese plum. Resistant to transport. Vigorous tree, great fertility. It is cultivated in the U.S.A., France, Italy and South Africa, available from January to May and June to August. In Spain, the harvesting takes place in the middle of June.

" Black Amber"
Japanese variety, black colour, big size, round shape, a bit flattened. The pulp is amber, the firm flesh is not adhered to the bone, good taste. Resistant to handling. Productive. Vigorous tree of very erect habit, self-sterile. It comes from the U.S.A. and the maturation period in warm zones is during the last week of June.

" Santa Rosa’
Japanese plum, with a big, round and hearted fruit. Deep red skin. Amber yellow or pale carmine flesh, very juicy, sweet and perfumed, with a flavour that reminds of the strawberry. Erect habit tree, medium development and very fertile. Partially self-fertile. It is from America, but mainly cultivated in France, Italy, Spain and South Africa. It is available from December to February (South Africa) and from June to November (in other producing countries). In Spain, harvesting takes place in the middle of July.

" Reina Claudia Verde’
European plum of medium size, rounded, green, thin and juicy pulp, characteristic scent and flavour. The stone comes off easily. Partially self-fertile. Excellent for table consumption, stewed or tinned fruit and jam. It is produced in Belgium, France, England and Spain. Available in August and September. In Spanish warm areas the harvesting takes place in July-August.

" Reina Claudia de Oullins"
It is a European plum. French variety. Vigorous and productive tree. Great fruit, golden pale green. Very juicy and pale flesh, not very sweet flavour. The stone does not come off very easily. It is one of the most widespread varieties. Pollinizer variety: Reina Claudia Verde. Maturation during the second fortnight of July (in Zaragoza) and available in the market until August.

" Angelino’
It is a Japanese variety with great size fruits, dark red colour and even darker when ripe. Sweet flavour and yellow flesh. Not very productive but very good fruit conservation. Maturation from the middle to the end of September.