Muni Ram

Effect of the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum on the essential oil yield related characters and nutrient acquisition in the crops of different cultivars of menthol mint (Mentha arvensis) under field conditions.

The effects of inoculation with vesicular-arbuscular mycorrhizal (VAM) fungus Glomusfasciculatum on the root colonization, growth, essential oil yield and nutrient acquisition of three cultivars of menthol mint (Mentha arvensis); Kalka, Shivalik and Gomti, were studied under field conditions. The VAM inoculation significantly increased the root colonization, plant height, fresh herbage and dry matter yield. oil content and oil yield as compared to non-inoculated cultivars. The effect of VAM inoculation on the root colonization, growth and yield of mint was more pronounced with the cv Shivalik than the cvs Kalka and Gomati, indicating Shivalik as a highly mycorrhizal dependent genotype. VAM inoculation significantly increased the uptake of N, P and K by shoot tissues of mint, but most markedly increased the uptake of P. The VAM-inoculated mint plants depleted the available N, P and K in the rhizosphere soil as compared to non-inoculated control plants, however the extent of nutrient depletion was greater for P than N and K. We conclude that the VAM inoculation could significantly increase the root colonization, growth, essential oil yield and nutrient acquisition of mint for obtaining economic production under field conditions.

Influence of an organic mulching on fertilizer nitrogen use efficiency and herb and essential oil yields in geranium (Pelargonium graveolens).

In a field study, conducted at Lucknow ( 26.5 degrees N, 80.5 degrees E and 120 m altitude), India for two years (1996-1997 and 1997-1998), eight treatment combinations of two variables of organic mulch (paddy straw at 7 t/ha and no mulch) and four levels of fertilizer nitrogen (0, 80, 160 and 240 kg/ha) were examined to observe the effect of organic mulching on N-use efficiency and essential oil yield in a multi-harvested geranium crop. Results revealed that application of paddy straw mulch increased the herb and essential oil yields in geranium by 23% and 27%, respectively, over the unmulched control at planted crop harvest. Corresponding values at regenerated crop harvest were 18.7% and 19.2%. A significant response to N was observed with 160 kgN/ha in mulched plot over the same level of N in the unmulched plot. Using paddy straw mulch, nitrogen uptake by plants of planted and regenerated crops was increased by 33% and 28.4%, respectively, over the unmulched control. Apparent N recoveries by planted and regenerated crops were estimated to be 33.7% and 22.7% for the unmulched control, as against 40% and 29.2% with paddy straw mulch at 160 kgN/ha. The quality of essential oil of geranium in terms of its major constituents, citronellol and geraniol, was not affected by the use of organic mulching and nitrogen fertilization and these constituents were found to be of a standard acceptable in international trade. It was concluded from this study that use of an organic mulch with 160 kgN/ha proved better in terms of economising 80 kgN/ha to produce an economic yield of 96.1 kg geranium oil from two harvests under subtropical conditions of the north Indian plains. At 160 kgN/ha, paddy straw mulch application permitted the geranium crop to produce 18.4 kg/ha more oil which gave an additional return of Rs. 53,600/ha than that of unmulched control. Paddy straw mulch and nitrogen fertilization had no adverse effect on the quality of essential oil of geranium.

Yield improvement in the regenerated and transplanted mint Mentha arvensis by recycling the organic wastes and manures

Abstract Field experiments were carried out during winter-summer seasons of 1994 and 1995 at Lucknow, India, located at 26·5°N, 80·5°E and 120 m above mean sea level to study the effects of (i) organic wastes and/or manures on the regenerated and transplanted mint crops and (ii) rescheduling of the harvest time in the sucker-planted crop. The treatments studied were of citronella ( Cymbopogon winterianus ) distillation waste and pea ( Pisum sativum ) straw mulches at 7 t ha −1 , farmyard manure (FYM) at 20 t ha −1 at planting, FYM at 20 t ha −1 after the first harvest and a control (no application of mulch and FYM), supplementary to the inorganic N fertilisation at 0, 80, 160 and 240 kg N ha −1 . The harvesting times investigated in the sucker-planted crop were 90, 100, 110 and 120 days after planting. The use of citronella distillation waste as mulch and FYM were most effective in enhancing the total herb and essential oil yields (planted + regenerated harvests) when the planted crop was harvested at 110 days after planting. The yield of regenerated crop improved significantly in the plots that had received citronella mulch or FYM during the planted-crop period, as compared with that of the control; citronella-waste mulch treatment proved better than FYM treatment. Application of 160 kg N ha −1 in the form of inorganic fertiliser and citronella distillation waste mulch at 7 t ha −1 met the N requirements of the transplanted mint crop. Mulch applications improved the efficiency of utilisation of inorganic N by about 10%. Application of mulch had no effect on the quality of the oil obtained in the first harvest of the sucker-planted crop and in the transplanted crop. It is recommended that under subtropical conditions, citronella distillation waste mulch should be applied after the sprouting of suckers during the planted crop period to obtain higher yields of herb and essential oil from the planted as well as the regenerated crop harvests. In order to get the maximum yield advantages from both the harvests, the planted crop should be harvested at 110 days after planting. The use of citronella-waste mulch with 160 kg N ha −1 minimised the cost of transplanted mint production by a factor equivalent to one third.

Irrigation and nitrogen requirements of Bergamot mint on a sandy loam soil under sub-tropical conditions

Abstract A field experiment was conducted with Bergamot mint ( Mentha citrata Ehrh) var. Kiran at Lucknow, India in 1992 and 1993 under four soil moisture regimes (0.6, 0.9, 1.2 and 1.5 irrigation water: cumulative pan evaporation (IW:CPE) ratio) and four levels of nitrogen (0, 80, 160, 240 kg ha −1 ). Soil moisture regimes maintained at 1.2 IW:CPE ratio significantly increased the crop growth, and herb and essential oil yields as compared with those having 0.6 and 0.9 IW: CPE ratio. The former produced 86.4% and 10.0% higher fresh herbage than the latter two moisture regimes, with a 63% and 12.7% increase in essential oil yield, respectively. Application of 160 kg N ha −1 was found to be the best with respect to the yield of the crop, but increased levels beyond this did not cause deleterious effects on the synthesis of monoterpenes in the essential oil. High moisture regimes maintained during summer months proved significantly better for efficient utilization of water and nutrient by the crop. The quality of the essential oil in terms of its two major constituents, linalool and linalyl acetate increased favourably up to 1.2 IW:CPE ratio, while the former decreased and the latter improved slightly with the higher moisture conditions prevailed during both the harvest. Higher rate of N fertilization (240 kg ha −1 ) favoured the synthesis of linalool, a major constituent of essential oil only during the first harvest. It is concluded that the Bergamot mint should be irrigated at 1.2 IW:CPE ratio with an application of 160 kg N ha −1 in the sub-tropical climate of India

Influence of straw mulching on fertilizer nitrogen use efficiency, moisture conservation and herb and essential oil yield in Japanese mint (Mentha arvensis L.)

In a field study, the influence of organic mulches viz. paddy straw and citronella (Cymbopogon winterianus Jowitt) distillation waste on herb and essential oil yield and fertilizer N use efficiency in Japanese mint (Mentha arvensis L.) were examined for two years. Herb yield (dry weight) increased by 17 and 31% with paddy straw and citronella distillation waste, respectively over the use of no mulch. Essential oil yield also significantly increased due to mulching. A significant response to N was observed with 200 kg N ha−1 in unmulched plots as against 150 kg N ha−1 in mulched plots. Mulched soils have been observed to contain 2 to 4% higher moisture as compared to unmulched soils. Nitrogen uptake by plants increased by 18 and 25% over no mulch with using paddy straw and citronella distillation waste, respectively.

Minimizing volatilization and leaching losses of nitrogen by different nitrogen carriers in Japanese mint (Mentha arvensis L.)

Japanese mint, an important essential-oil-bearing crop, is cultivated for menthol used in cosmetic and pharmaceutical industries. It requires a high level of nitrogen fertilizer, between 150 and 250 kg N/ha depending on the agro-climatic conditions (Ghosh & Chatterjee, 1976; Yadav, Mohan & Ram, 1983). During the crop cycle (January–August), frequent irrigations and high intensive rains result in poor N recovery especially on light-textured soils. With a view to reduce losses of N and improve N recoveries, the relative efficiency of neem-cake-coated urea, laccoated urea and urea supergranules has been investigated in comparison with prilled urea in Japanese mint.

Variation in Quality of Essential Oil Distilled from Vegetative and Reproductive Stages of Tagetes minuta Crop Grown in North Indian Plains

Abstract The essential oil yield and quality of Tagetes minuta was field tested in north Indian plain conditions of Lucknow, India in winter (rabi) season of November 1997 to April 1998. The shoot oil distilled from the crop of Banuri land race at full flowering stage was rich in dihydrotagetone (32.0%), (Z)-tagetone (16.7%) and (Z)-β-ocimene (133%). In comparison to the oils distilled from flower bearing plants, the oil from plants at vegetative stage(s) of growth contained (E)- and (Z)-tagetenones and (E)- and (Z)-tagetones at higher levels (27.1% and 31.2%, respectively) and dihydrotagetone and (Z)-β-ocimene at lower levels (13.6% and 6.1%, respectively). The oils obtained from the leaves of plants bearing flowers (capitula) at different stages of development were pre-eminent in dihydrotagetone, present in 50-60% concentration. The capitula oils were somewhat similar to leaf oils of reproductively mature plants in their monoterpenoid composition.

Response of lemongrass (Cymbopogon flexuosus) under different levels of irrigation on deep sandy soils

Abstract The growth and herbage and oil production of East Indian lemongrass (Cymbopogon flexuosus) in response to different levels of irrigation water (IW) [0.1, 0.3, 0.5, 0.7, 0.9, 1.1, 1.3 and 1.5 times cumulative pan evaporation (CPE)] were evaluated on deep sandy soils at the research farm of the Central Institute of Medicinal and Aromatic Plants, Lucknow, from 1991 to 1993. In general, an increment in the level of irrigation increased the plant height up to 0.7 IW:CPE ratio. The response of irrigation levels on tiller production of lemongrass differed with the season of harvest. Maximum tillers/clump during the 2nd, 3rd, 6th and 7th harvests were in response to irrigation levels 0.9, 0.5, 0.7 and 0.7 IW:CPE ratio, respectively. Oil content had an inverse relationship with the levels of irrigation, specially during the 1st, 2nd, 5th and 6th harvests. Significantly higher herb and essential oil yields were recorded at 0.7 IW:CPE ratio, irrespective of season of harvest. The maximum total herb (22.79 t/ha in first year and 33.11 t/ha in second year) and oil (146.2 l/ha in the first year and 205.3 l/ha in the second year) yields were recorded at 0.7 IW:CPE ratio. The quality of oil with respect to the major chemical constituents (Citral-a, Citral-b and geraniol) was not changed. At the optimum level of irrigation (0.7 IW:CPE ratio) the water used by lemongrass was 118.2 cm for first year and 123.8 cm for the second year. Water-use efficiency was found to be higher (1.66 l oil/ha-cm) in the second year than the first year (1.23 l oil/ha-cm). For optimum yield potential of lemongrass on deep sandy soils of sub-tropical climate, the crop received 17 irrigations in the first year and 14 irrigations in the second year of harvests. Irrigations were made during the dry winter and summer months.

Water requirement and productivity of palmarosa on sandy loam soil under a sub-tropical climate

Abstract Water requirement, productivity and water use efficiency of a perennial aromatic grass, palmarosa (Cymbopogon martinii stapf cv motia), were studied under different levels of irrigation (0.1, 0.3, 0.5, 0.7, 0.9, 1.1, 1.3 and 1.5 IW:CPE ratio) for three years (July-June) during 1990 to 1993, on sandy loam soils under subtropical climate of Lucknow. Growth, herb and essential oil yield increased significantly up to 0.5 IW:CPE ratio. At 0.5 IW:CPE ratio palmarosa produced 47.3 tons of fresh herb and 227.3 kg of essential oil ha−1 yr−1. Further increase in irrigation levels caused an adverse effect on growth and yield of palmarosa. Irrigation levels did not affect the quality of oil in terms of its geraniol and geranyl acetate contents. Water requirement of palmarosa was worked out to be 89.1 cm. The highest water use efficiency of 2.97 kg oil ha−1 cm−1 was recorded at 0.1 IW:CPE ratio, at 0.5 IW:CPE ratio (optimum) it was 2.55 kg oil ha−1 cm−1 Irrigation scheduled at 0.5 IW:CPE ratio gave the highest net return of Rs 51963 ha−1 yr−1.

Herb yield and bacoside: A content of field-grown Bacopa monnieri accessions

ABSTRACT A field trial of five accessions of Bacopa monnieri (L.) Pennell was conducted during 1997 to 1998, at Lucknow, India, to standardize cultivation procedures for domestication of this medicinal herb. The accessions, monitored for growth and bacoside-A yields over 18 months, could be maintained as perennials, but growth properties were sensitive to the growing season. Loss of shoot biomass occurred in winter (December-February) and the growth rate was higher in the monsoon season (July-September) than in summer (March-June). Bacoside-A content of herb was high from September through March and in June. Suitable harvest times for high yields of bacoside-A were June and September through November. An accession from Guwahati in Assam state of India yielded more bacoside-A than all other accessions.