Dasha Ram

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.

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

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.

Productivity of Citronella Java (Cymbopogon winterianus) with Spring Legume Intercrops under Subtropical Environment

Abstract A field experiment was carried out for two years (1994 and 1995) at the Research Farm of the Central Institute of Medicinal and Aromatic Plants, Lucknow, India to study the yield advantages of legume-citronella Java intercropping system. Five treatment combinations of monoculture and intercrops such as citronella Java sole, green gram (Phaseolus radiatus) sole, black gram (Phaseolus mungo) sole, citronella Java + green gram and citronella Java + black gram, were tested on sandy loam soil during the spring season. Results revealed that spring legumes intercropped with citronella Java showed greater yield advantages in terms of main crop equivalent yield of essential oil compared with that of monoculture crop. Black gram and green gram intercropping systems increased the yield advantages by 19% and at par in 1994 and 10% and 24% in 1995, respectively over monoculture control. Former intercrop system resulted into higher productivity efficiency; land equivalent ratio (LER) 1.88, area time equivalent...

Towards sustainable production of peppermint (Mentha piperita L.) through integrated use of vermicompost and cowpea green manuring with synthetic nitrogen fertilization

A field experiment with peppermint (Mentha piperita L.) was conducted in a sandy loam (Typic ustifluvent) soil during 2007 and 2008 at Lucknow, India. Ten treatments consisting of control (no synthetic or organic nitrogen fertilization), synthetic nitrogen fertilization (SN) 75, 150 and 225 kg ha−1 alone, vermicompost (VC) 3 t + 37.5 kg SN ha−1, VC 6 t + 75 kg SN ha−1 and VC 9 t + 112.5 kg SN ha−1 and intercropping of one, two and three rows of cowpea for green manuring in combination with 50, 100 and 150 kg SN ha−1, respectively, were evaluated in a randomized block design. Integrated use of VC 9 t with 112.5 kg SN ha−1 produced maximum essential oil (94.3 kg ha−1), increased the herb and essential oil yields by 104 and 89%, respectively, over control and reduced SN use by 50%, without affecting the quality of essential oil. Application of VC and intercropping of cowpea for green manuring significantly improved the organic carbon, available N, P and K content in soil over SN alone. To get sustainable production of peppermint, application of VC 9 t ha−1 along with 112.5 kg N ha−1 through synthetic fertilizer is recommended for light textured sandy loam soils.

Sustainable production of pigeon pea and sarpagandha (Rauvolfia serpentina) by intercropping

Sarpagandha (Rauvolfia serpentinaBenth. Ex Kurz.), a natural source of the alkaloid reserpine, is generally found growing under partial shade of deciduous forests in the tropics and subtropics. To promote its commercial cultivation under subtropical environment of the north Indian plains, a field trial was conducted during 2006–2009 to optimize the plant populations (row ratios) of pigeon pea and sarpagandha for higher productivity, land utilization efficiency and economic return in an intercropping system. Intercropping of two rows of sarpagandha with pigeon pea sown at a row distance of 90 cm proved highly beneficial in terms of total production (5.15 t ha−1 grain and 10.27 t ha−1 straw + stalk of pigeon pea and an additional dry root yield of 2.56 t ha−1 of sarpagandha) from a unit area and time. The highest land equivalent ratio, LER (2.21), area time equivalent ratio, ATER (1.76), monetary equivalent ratio, MER (2.0), land-use efficiency, LUE (198%) and net return (Rs. 273,810 ha−1) were obtained for the combination of pigeon pea and sarpagandha in 1:2 row ratio. Integration of two rows of sarpagandha as an intercrop with pigeon pea sown at 90 cm row distance is recommended for sustainable crop production.