The Otto of Rose Industry.
Mr. Ernst Schmalfuss, a German horticulturist, has been spending a considerable time in Bulgaria to investigate the conditions of the otto of rose industry in that country. Mr. Schmalfuss went to Bulgaria as the agent of a German firm of essential oil distillers who have lately been endeavoring to create an otto of rose industry in Germany, and who desired to have an expert's opinion on the question whether it is feasible to grow the Thracian rose in Western Europe.
The information which has been collected belongs of course to the firm who bore the expense of the journey, but Mr. Schmalfuss has obtained their permission to publish certain details on the subject of his investigations. Mr. Schmalfuss went to Bulgaria with an open mind, and returned thence a firm believer in the future of an otto industry in Western Europe.
There are two principal rose-growing districts in Bulgaria, the one extending from Yeni-Sagra to Carlowa on the southerly slopes of the Balkans, and the other situated near Chirpan, south of the Karadsha-Dagh. The most widely-different estimates prevail regarding the total area under cultivation, and no reliable figures are obtainable. There is much variation in the soil of the rose-districts, the prevailing formation being a light loam, rich in lime (1.26 per cent.) but almost devoid of phosphoric acid, of which only traces were found in a sample sent to Germany for analysis.
The proportion of nitrogen is moderate, being 0.14 per cent., but the soil is remarkable for its richness in potassium, of which 0.64 per cent. was present in the specimen analyzed. It is not known whether the presence of potassium exercises a special influence on the growth of the flowers; if so, the application of potash-manure would be advisable. In Bulgaria the rose-fields are sheltered from the north wind by the mountain ranges against which they are situated, but it is thought that it would be rather an advantage than otherwise if they were from time to time exposed to a cool wind, the plants being singularly hardy and able to withstand without injury a temperature of -4° Fahr. On the other hand, scarcely a season passes in which the plants do not suffer from excessive heat, the high temperature prevailing during certain months being, in fact, the greatest enemy of the shrubs during the flowering and gathering time.
The variety which is used for distilling purposes in Bulgaria is the so-called Thracian rose, a plant of exceedingly rapid growth, flowering sparingly in the first year, and yielding a full crop on the third, When it attains maturity. It is said that, under certain conditions, the plants attain an age of fifty years. The plant bears red or white flowers, the former being about five times as numerous as the latter. Both varieties of flowers are of a very powerful and agreeable odor, but the oil distilled from the white flowers is the finest, although the red roses are richer in essential oil. The Thracian rose exceeds all other varieties in flowering property, weak specimens bearing as many as 500 flowers, while fine plants, if properly cultivated are able to produce nearly double that number. The rose, are small and light , about 220 fresh flowers going to the lb., or about twice the number of ordinary centifolia flowers which are required to make up that weight.
The flowers of the Thracian rose are rather thin, and their richness in essential oils lies in the ovary and the stamens (of which there are an extraordinary number), rather than in the petals. For distilling purposes the entire flower of the Thracian rose is taken, while of the other varieties the corolla leaves alone am employed. Almost every small Bulgarian farmer distils his own oil, the stills used being of the most elementary description, and it is thought that if a Western firm were to undertake the distilling a larger percentage and better quality of oil might easily be obtained. The roses am grown in fields, where they are placed in rows about 2 yards apart, and alternating with rows of grape vines or kitchen vegetables. To a practical man it would appear that in the Bulgarian fields the plants am grown too closely together and have no mom left to expand properly. As hints to intending experimenters in Western Europe, Mr. Schmalfuss recommends that the soil should be well manured with old, partly-decomposed manure, the application of which should be repeated every third year. The plant ,should be placed in rows, about 8,000 trees to the acre, and during the first two years the rows of rose-plants may alternate with rows of kitchen vegetables. It may be found to pay to cut the shrubs in the second year close to the ground. The yield of that year is of course lost by this proceeding, but the luxuriance of the plant for the future is thereby much increased. After the third year the planting of vegetables must be discontinued. The soil must be kept free from weeds and rendered loose twice a year by hoeing. The fields might, experimentally, be protected at the north side by hedges. The flowers must be gathered early in the morning and placed loosely in open baskets, which should be kept in the shade.
Of the roses common in Western Europe the light and dark red varieties of moss, Bourbon, and Remontant roses are richest in essential oil, and might be employed advantageously, Mr. Schmalfuss thinks, so long as the Thracian roses are not obtainable in quantities. Unfortunately, it would appear that, for the present, at least, there is no prospect of a supply of Thracian roses sufficient to admit of a proper experiment. When Mr. Schmalfuss commenced his investigations in Bulgaria he did not meet with any considerable opposition on the part of the native otto merchants, who, at that time, appear to have been perfectly skeptical regarding the possibility of the remunerative distillation of otto outside their own country. But when Mr. Schmalfuss, encouraged by his success, endeavored to obtain a first wagon-load of plants for export to Germany, the Bulgarian otto trade suddenly raised an outcry and prevailed upon the Government to issue an order strictly prohibiting the export of plants. Efforts will be made to obtain the repeal of this order, and Mr. Schmalfuss' friends are sanguine that at any rate they will ultimately succeed in obtaining a sufficient number of plants; but for the moment their plans, so far as the wholesale import of Thracian roses into Germany is concerned, are frustrated.—The Chemist and Druggist, December, 1886, p. 809.