S. K. Kothari

Volatile Constituents in Oil from Different Plant Parts of Methyl Eugenol-Rich Ocimum tenuiflorum L.f. (syn. O. sanctum L.) Grown in South India

Abstract Ocimum tenuiflorum L.f. (syn. O. sanctum L.) (Lamiaceae) is an indigenous ayurvedic medicinal plant of India and is popularly known as holy basil/sacred basil. Oils obtained by hydrodistillation from leaves, stems, inflorescence and whole herb were analyzed by GC and GC/MS and retention indices. Methyl eugenol was the major constituent of all the oils (72.5%, 75.3%, 83.7% and 65.2% in oils from whole herb, leaf, stem and inflorescence, respectively). β-Caryophyllene was the second most dominant constituent and the respective concentration in each oil (5.5%, 6.4%, 2.7% and 12.0%).

The Effect of Row Spacing and Nitrogen Fertilization on Scotch Spearmint (Mentha gracilis Sole)

ABSTRACT The effect of row spacings (45, 60 and 75 cm) and various amounts of nitrogen fertilizer (0,100,200 and 300 kg N/ha) on plant growth, essential oil production and composition of Scotch spearmint was studied in the field during 1987 and 1988 in Lucknow, India. Nitrogen application increased plant height and leaf area index while decreased leaf-stem ratio and oil concentration, irrespective of row spacings. The green herbage and oil yields increased significantly up to an application of 200 kg N/ha at 45 or 60 cm row spacing as against up to 300 kg N/ha at 75 cm row spacing. The higher N application at 75 cm row spacing, however, did not increase oil yield compared to application of 200 kg N/ha at 60 cm row spacing. Row spacing influenced various response functions and optimum N rate. At optimum N, response per kg N, net return per kg N and benefit-cost ratio were highest at 60 cm row spacing. Oil concentration and composition in green herb were related to leaf area index and N concentration in the...

Morphology, yield and quality of ashwagandha (Withania somnifera L. Dunal) roots and its cultivation economics as influenced by tillage depth and plant population density

Summary Ashwagandha (Withania somnifera L. Dunal; Solanaceae) is being cultivated around the world mainly for its root which has rejuvenative properties. Field experiments during 1999–2001 under semi-arid tropical conditions of Hyderabad, India studied the effect of tillage depths (15 and 30 cm) and plant population densities (20, 40, 60 and 80 plants m–2) on root morphology, yield and quality and cultivation economics of ashwagandha. Preparatory tillage to 30 cm depth in combination with a density of 60 plants m–2 gave the highest root yield of 1.2 t ha–1 which was 50% higher than that following 15 cm tillage depth and the same density. This is attributed to the favourable effect of the former treatment leading to 33, 37 and 21% increases in plant height, number of branches per plant and shoot biomass yield, respectively. Further, this treatment produced most (68%) best quality root pieces. Main root length, length of lateral roots and diameter of lateral roots were significantly increased, while the diameter of main root and the number of laterals decreased. Furthermore, increase in plant density from 20–80 plants m–2 increased production of best quality roots from 42% to 59% under shallow tillage and from 53% to 71% of root yield under deep tillage. The implications of change in root morphology are discussed in the light of production of different grades of roots, their market preferences and economics. Deep tillage was equally advantageous for seed production, but plant population density for maximum seed yield (211 kg ha–1) was lower at 40 than at 60 plants m–2 for maximum root yield. Maximum gross and net returns and benefit-cost ratio occurred following the highest root yield.

Chemical weed control in Bulgarian coriander (Coriandrum sativum L.)

Abstract Field investigations carried out in two winter seasons of 1984–85 and 1985–86 on clay‐loam soil at the Central Institute of Medicinal and Aromatic Plants, Regional Centre, Pantnagar, Naintial, India revealed that unrestricted weed growth reduced the seed and oil yields of Bulgarian coriander (Coriandrum sativum L. cv. S 33) by 40.3 and 37.0%, respectively. Applications of pendimethalin and fluchloralin at 0.75 and 1.00 kg a.i./ha, respectively causing 76.5 and 71.9% weed control, were most promising treatments, and gave seed and oil yields comparable to weed‐free check. Applications of oxadiazon at 0.25–0.75 kg a.i./ha and propanil at 1–2 kg a.i./ ha, although proved selective but failed to produce desired results. None of the treatments impaired the quality of coriander seed oil, measured in terms of d‐linalool content.

Production techniques for the cultivation of safed musli (Chlorophytum borivilianum)

Summary Chlorophytum borivilianum (family Liliaceae) is a high-value medicinal plant becoming rare because it is harvested fromthe wild. To encourage its adoption as a crop plant, propagation and cultural methods were investigated under semi-arid tropic conditions of Hyderabad, India. Single tubers will sprout if attached to a portion of crown, and yields of fresh tuber and musli (the peeled and dried end-product) were improved by increasing the planting weight of tubers to 12.5.g per unit. Further, at this unit weight of planting material, the tuber multiplication ratio (ratio between fresh tuber yield andweight of planting material, 4.63) and musli-fresh tuber ratio (0.17) were highest. Yields were also increased by farmyardmanure (FYM) at 40.t ha-1 because of significant improvements in number, length and thickness of tuber and musli-fresh tuber ratio. Plant size and yields of fresh tuber and musli were greater in a potexperiment with up to 25.mg N kg-l of soil. Pinching of inflorescences increased leaf (18%) and tuber lengths (32%) and the yields of fresh tubers (22%) and musli (30%).

Pre-Flowering Harvesting of Ocimum gratissimum for Higher Essential Oil and Eugenol Yields Under Semi-Arid Tropics

Abstract In spice basil (Ocimum gratissimum L.), contribution of leaves, stalks and inflorescences were 59%, 23% and 18% to total plant biomass and 80%, 1% and 19% to total oil yield, respectively. The leaf oil was richer in eugenol but simultaneously had lower (E)-β-ocimene, compared to the inflorescence oil. Harvesting at pre-flowering produced 12.5%, 24.1%, 35.5% and 50.0% higher biomass yield compared to harvesting at 25%, 50%, 75% and 100% flowering, respectively, in the first year of cropping. The respective increase was 16.8%, 22.0%, 38.2% and 63.2% in the second year. Late harvested crop (100% flowering) contained the highest amount of essential oil and it decreased in the order of harvesting at 100% flowering > 75% flowering > 50% flowering > 25% flowering > pre-flowering treatment. The total oil yield was, however, significantly higher (15.8–19.9% and 12.7–33.6% in first and second years, respectively) with pre-flowering compared to all other harvest treatments. Pre-flowering harvested crop produced oil containing the highest amount of eugenol and it decreased in the order of harvesting at pre-flowering > 25% flowering > 50% flowering > 75% flowering > 100% flowering treatment.

Chemical Weed Control in Japanese Mint (Mentha arvensis L.)

Field experiment conducted at the Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar during 1985 and 1986 revealed that unrestricted weed growth reduced the herbage and oil yields of Japanese mint by 86.6 and 87.8%. respectively. Pendimethalin at 1.5 and oxyfluorfen at 0.3 kg/ha as pre-eme. application recorded the highest weed control efficiency and also produced the green herbage, oil and menthol yield compared to the yield of weed free treatment. Fluchloralin as preplant soil incorporation was toxic to mint crop. mint oil.

Harvest management in rose-scented geranium (pelargonium sp.) for higher essential oil yield and superior quality under semi-arid tropics

Rose-scented geranium (Pelargonium species) is grown as a perennial crop for production of high value essential oil, which finds application particularly in high-grade perfumery, cosmetic products and aromatherapy. A field investigation was carried out during 2001-02 to study the harvest of shoots of the crop on attainment of 4, 6 or 8 fully expanded leaves (FEL) and its effect on essential oil yield and quality under semi-arid tropics. Harvesting of shoots with 4 FEL produced 6 harvests / annum against 4 and 3 harvests per annum in the treatments representing harvest of shoots with 6 and 8 FEL, respectively. Highest biomass yield (18.1 t ha−1 annum−1) among the treatments was, however, observed in the treatment 8 FEL. On the contrary, essential oil content in the biomass of treatment of 4 FEL was 27.3 and 55.5% higher than 6 FEL and 8 FEL treatments, respectively. Similarly, estimated essential oil yield in the treatment of 4 FEL was 17.4 and 30.7% higher than 6 FEL and 8 FEL treatments, respectively. Furthermore, the essential oil produced in the 4 FEL treatment was found to contain higher citronellol, geraniol, citronellyl formate, cis- and trans-rose oxides and 10 epi-γ-eudesmol and lower linalool, menthone and isomenthone, than other harvest treatments. The gross and net returns were also remarkably higher in the 4 FEL treatment beside benefit-cost ratio. It is suggested that rose-scented geranium can be harvested more frequently (six harvests per annum) on attainment of shoots with 4 fully expanded leaves in order to produce higher essential oil yield with superior quality and higher return.

Critical periods of weed interference in Japanese mint (Mentha arvensis L.)

Abstract Results from two sets of field experiments carried out during 1984 and 1985 revealed that Japanese mint (Mentha arvensis L.) was associated with both broad‐leaf and grass weeds dominant in summer and rainy seasons representing the period of first and second harvests, respectively. The weed biomass exceeded that of the crop from the very beginning of the crop cycle, and the most rapid increase in weed biomass was noted between 30 and 45 days after planting in first harvest and the first 45 days in second harvest. Unrestricted weed growth significantly reduced Japanese mint oil yield by 74.4% and 70.0%, respectively in first and second harvests. The critical period of weed interference was between 30 and 75 days in first harvest and 15 and 45 days in second harvest. Weed infestation during the critical periods caused significant reduction in plant height and herb and oil yields, and weed infestation beyond the critical periods did not have any significant influence on these parameters. The leaf:ste...