The cultivation of oranges, lemons and their congeners (collectively designated in Italian by the term _agrumi_) is of comparatively modern date, the introduction of the _Citrus Bigaradia_ being probably due to the Arabs. Sicily is the chief centre of cultivation--the area occupied by lemon and orange orchards in the province of Palermo alone having increased from 11,525 acres in 1854 to 54,340 in 1874. Reggio Calabria, Catanzaro, Cosenza, Lecce, Salerno, Naples and Caserta are the continental provinces which come next after Sicily. In Sardinia the cultivation is extensive, but receives little attention. Both crude and concentrated lime-juice is exported, and essential oils are extracted from the rind of the _agrumi_, more particularly from that of the lemon and the bergamot. In northern and central Italy, except in the province of Brescia, the _agrumi_ are almost non-existent. The trees are planted on irrigated soil and the fruit gathered between November and August. Considerable trade is done in _agro di limone_ or lemon extract, which forms the basis of citric acid. Extraction is extensively carried on in the provinces of Messina and Palermo.
Among other fruit trees, apple-trees have special importance. Almonds are widely cultivated in Sicily, Sardinia and the southern provinces; walnut trees throughout the peninsula, their wood being more important than their fruit; hazel nuts, figs, prickly pears (used in the south and the islands for hedges, their fruit being a minor consideration), peaches, pears, locust beans and pistachio nuts are among the other fruits. The mulberry-tree (_Morus alba_), whose leaves serve as food for silkworms, is cultivated in every region, considerable progress having been made in its cultivation and in the rearing of silkworms since 1850. Silkworm-rearing establishments of importance now exist in the Marches, Umbria, in the Abruzzi, Tuscany, Piedmont and Venetia. The chief silk-producing provinces are Lombardy, Venetia and Piedmont. During the period 1900-1904 the average annual production of silk cocoons was 53,500 tons, and of silk 5200 tons.
The great variety in physical and social conditions throughout the peninsula gives corresponding variety to the methods of agriculture. In the rotation of crops there is an amazing diversity--shifts of two years, three years, four years, six years, and in many cases whatever order strikes the fancy of the farmer. The fields of Tuscany for the most part bear wheat one year and maize the next, in perpetual interchanges, relieved to some extent by green crops. A similar method prevails in the Abruzzi, and in the provinces of Salerno, Benevento and Avellino. In Lombardy a six-year shift is common: either wheat, clover, maize, rice, rice, rice (the last year manured with lupines) or maize, wheat followed by clover, clover, clover ploughed in, and rice, rice and rice manured with lupines. The Emilian region is one where regular rotations are best observed--a common shift being grain, maize, clover, beans and vetches, &c., grain, which has the disadvantage of the grain crops succeeding each other. In the province of Naples, Caserta, &c., the method of fallows is widely adopted, the ground often being left in this state for fifteen or twenty years; and in some parts of Sicily there is a regular interchange of fallow and crop year by year. The following scheme indicates a common Sicilian method of a type which has many varieties: fallow, grain, grain, pasture, pasture--other two divisions of the area following the same order, but beginning respectively with the two years of grain and the two of pasture.