Nitrogen fertilizer influences yield and essential oil of ocimum americanum cultivated in Egypt

The present study was carried out during two successive seasons at the Experimental Farm of Cultivation and Production of Medicinal and Aromatic Plants Department, National Research Center, Giza, Egypt.The aim of this study was to investigate the effect of differc-t nitrogen levels on the yield and essential oil production of Ocimum cimericanum.Herbage yield was significantly increased with nitrogen fertilization especially at high levels [40, 60 and 80 kg N/fed]. Both fresh and dry yield of herb [ton/fed] in both seasons were significantly influenced. Similarly, the same effect was obtained on leaves fresh and dry yield per feddan [4200 m[2]]. The highest herb and leaves yields were obtained as a result of 60 kg N/fed. The highest oil percentage was associated with the highest nitrogen dose [80 kg N/fed] in most cuts of both seasons. All nitrogen doses significantly increased oil content [mi/plant] comparing to unfertilized plants. In all cuts of both seasons, 60 kg N/fed produced the highest oil content. The maximum total oil yield [ml/plants or 1/fed] were obtained with 80 and 60 kg N/fed in the lst and 2nd seasons, respectively. All identified compounds were observed in the essential oil of all treatments. The major compound was found to be eugenol followed by methyl chavicol. Generally, the higher the nitrdgen was applied, the higher the methyl chavicol was produced; the opposite was true with eugenol.As a conclusion we may recommend the fertilization of Ocirnum arnericanurn L. plants with 60 kg N/fed as ammonium sulfate to maximize herb, leaves and oil production either per plant or per feddan

Response of two sweet fennel varieties to plant density and fertilization with different nitrogen sources

Two fennel [Poeniculum vulgare Mill.] varieties, Dulce and Azoricum, were field grown for fruits and oil production to select the most productive variety and the most suitable source of N fertilizers in fields supplemented with cattle manure, calcium superphosphate and potassium sulfate during preparation. Seeds of Dulce and Azoricum [sweet fennel] were sown in trays filled with a mixture of peatmoss and vermiculite [1:1 volme]. Forty days old seedlings were transplanted in the open field at 20, 30, 40 and 50 cm apart in rows 60 cm width. Plants were then grown without [control] or with further N fertilization of different chemical sources, Ammonium sulfate [AS], ammonium nitrate [AN] and urea were applied at rate of 70 kg N/feddan. With exception oil content, fennel plants of Azoricum proved to be superior in growth parameters and yields of fruits and oil of Dulce when grown under Egyptian environmental condition. Chemical fertilization with different N sources are surpassed organic fertilization [control] alone. Except fruits number, ammonium nitrate [AN] significantly increased fennel growth parameters and yields of fruits and oil in comparison with ammonium sulfate [AS] and urea in the two seasons. Wider spacing significantly increased growth parameters, except plant height, which decreased by increasing planting distance over 20 cm. As well as, yields of fruits and oil are decreased at 40 and 50 cm spacing, the highest values were obtained with 30 or 20 cm, respectively. Concerning of interaction between all treatments, ammonium nitrate significantly increased growth parameters and yields of fruits and oil in comparison with other fertilization treatments in both varieties and all planting distance during two seasons. Azoricum plants which received ammonium nitrate and planted at 30 cm gave the highest yields of fruits and oil. The extracted fruit volatile oil of planting distance at 20 cm was GLC analyzed for identifying its constituents in both tested varieties. Seventeen compounds were identified in both Dulce and Azoricum varieties. The major oil constituents of variety Dulce were trans-anethole, methyl chavicol and P-anisaldehyde, while methyl chavicol, trans-anethole and fenchone were the major compounds in Azoricum plants. The different nitrogen sources had a great effect on the oil constituents. Chemical fertilization of different N sources affected on Anethole [trans] in both varieties. Methyl chavicol fluctuated in Azoricumas and decreased in Dulce as a result of applied chemical fertilization