Crni orah pripada rodu Juglans, porodici orahovki koja je predstavnik reda orahovica ili oraholika. Toje vrsta istočnog dijela Sjeverne Amerike, koja je u Europu unesena 1629. godine. Na područje Istočne Slavonije i Srijema sjeme su 1899. godine donijeli šumari vukovarskog veleposjednika grofa Eltza. Razlozi unošenja sjemena crnog oraha u šumu bilo je sušenje hrasta lužnjaka, kao i cijena koju crnoorahovo drvo postiže na tržištu. Do 1925. godine radilo se prelaznim šumsko-poljskim načinom gospodarenja. Već 1925. godine bilo je oko 860 hektara pod kulturama crnog oraha. Vukovarski grofovi Eltz sijali su sjeme crnog oraha sve do Drugog svjetskog rata, kada napuštaju svoje posjede. S podizanjem kultura crnog oraha nastavilo se i nakon rata, a nešto intenzivnije sedamdesetih godina prošloga stoljeća, kada se sjeme sijalo na komasacijom i arondacijom dobivenim poljoprivrednim zemljištima. Sjeme se sijalo u redove razmaka 4 i 6 metara i to 500 kg po hektaru. Ponovno se međuredno uzgajaju poljoprivredne kulture, a nakon 3–4 godine unosi se obični bagrem. S podizanjem kultura crnog oraha nastavlja se krajem 20-og stoljeća i traje sve do danas. Sije se 500 kg sjemena crnog oraha po hektaru iste godine nakon sječe zrele šume. Brazde izvučene tanjurastim plugom razmaka su četiri metra, a sjeme se u redu sije na udaljenosti od 25 cm. Kilogram sjemena u prosjeku sadrži 20 sjemenki, što iznosi 10 000 sjemenki po hektaru. Sljedeće godine ponikne do 65 % sjemenki, a nakon druge godine na površini imamo do 55 % ili oko 5000 stabalaca crnog oraha. To nam jamči da ćemo marom dobrog gospodara u 80-oj godini dobiti 100–120 kvalitetnih stabala crnog oraha. Budući da se sijanje obavlja odmah nakon sječe, međuredno se nakon godinu-dvije javi dovoljan broj jedinki nekih od autohtonih ili alohtonih vrsta drveća, pa popunjavanje u svrhu dobivanja mješovite sastojine nijepotrebno. Šumarija Vukovar danas gospodari s oko 1300 ha kultura crnog oraha, dok bruto drvna zaliha iznosi oko 200 000 m3. Kulture crnoga oraha s ophodnjom od 80 godina postižu srednji pro mjer od oko 42 cm i srednju visinu od oko 33 m.Black walnut (Juglans nigraL.) belongs to the genus Juglans, the hickory family (Juglandaceae A. Rich. EX Kunth 1824), which is a representative of the Juglandales order. It is a species that is native to eastern North America that was brought to Europe in 1629. In 1899 the foresters of the great land owner Count Eltz introduced the seed of black walnut to the area of Eastern Slavonia and Syrmia, because of the deterioration of pedunculate oak (Quercus roburL.) and because of the price that the wood of black walnut reaches on the market. Till 1925 the forest management technique applied was the forest-field technique. Already in 1925 black walnut cultures covered around 860 ha. The Counts Eltz from Vukovar planted the seed of black walnut until the Second World War, when they left their land possessions. The cultivation of black walnut cultures continued after the war and intensified in the seventies, when the seed was planted in agricultural areas that were gained by reparcelling and consolidation of holdings. 500 kg of seed per ha is planted in rows with the spacing of 4 and 6 meters. Between the rows agricultural cultures are sown, and after three to four years black locust (Robinia pseudoacaciaL.) is planted. At the end of the twentieth century the growing of black walnut cultures continued and it goes on today. 500 kg of black walnut seed is planted per ha in the same year after the felling of the old-growth forest. The spacing between furrows drawn by disc-plough is four meters, and the seed is planted with a spacing of 25 cm within the row.A kilogram of seed contains around twenty grains on the average, which makes 10.000 grains per hectare. In the next year up to 65% of the grains sprout, and in the second year there are up to 55% or around 5.000 saplings of black walnut on the planted surface. This can guarantee that in the 80th year by efficient management we shall gain 100 to 120 quality trees of black walnut. Since the planting is done immediately after the felling, after a year or two between the rows there is a sufficient number of some of the indigenous or allochthonous tree species, so there is no need for subsequent planting so as to gain a mixed stand. The forestry office of Vukovar currently manages around 1.300 ha of black walnut cultures and the gross growing stock amounts to ca. 200.000 m3. The cultures of black walnut with a rotation period of 80 years reach an average breast height diameter of ca. 42 cm and an average height of ca. 33 m
