Performance of an age series of alnus-cardamom plantations in the Sikkim Himalaya: productivity, energetics and efficiencies. (1/9)

Biomass, net primary productivity, energetics and energy efficiencies were estimated in an age series of Alnus-cardamom plantations in the eastern Himalaya. The impact of stand age (5, 10, 15, 20, 30 and 40 years) on the performance of mixtures of N2-fixing (Alnus nepalensis) and non-N2-fixing (large cardamom) plants was studied. Large cardamom (Amomum subulatum) is the most important perennial cash crop in the region and is cultivated predominantly under Alnus trees. Net primary productivity was lowest (7 t ha(-1) per year) in the 40-year-old stand and was more than three times higher (22 t ha(-1) per year) in the 15-year-old stand. Agronomic yield of large cardamom peaked between 15 and 20 years of age. Cardamom productivity doubled from the 5- to the 15-year-old stand, and then decreased with plantation age to reach a minimum in the 40-year-old stand. Performance of cardamom in association of N2-fixing Alnus remained beneficial until 20 years of age. Annual net energy fixation was highest (444 x 10(6) kJ ha(-1) per year) in the 15-year-old stand, being 1.4 times that of the 5-year-old stand and 2.9-times that of the 40-year-old stand. Inverse relationships of production efficiency, energy conversion efficiency and energy utilized in N2-fixation against stand age, and a positive relationship between production efficiency and energy conversion efficiency suggest that the younger plantations are more productive. The Alnus-cardamom plantation system will be sustainable by adopting a rotational cycle of 15 to 20 years.  (+info)

Performance of an age series of Alnus-cardamom plantations in the Sikkim Himalaya: nutrient dynamics. (2/9)

Nutrient cycling, nutrient use efficiency and nitrogen fixation in an age series of Alnus-cardamom plantations were studied in the eastern Himalaya. The impact of stand age (5, 10, 15, 20, 30 and 40 years) on the nutrient dynamics of mixtures of N2-fixing (Alnus nepalensis) and non-N2-fixing (large cardamom) plants was assessed. Foliar nutrient concentrations of Alnus decreased with advancing age groups of plantations and showed an inverse relationship with stand age. Annual N fixation increased from the 5-year-old stand (52 kg ha(-1)), peaking in the 15-year-old stand (155 kg ha(-1)) and then decreased with increasing plantation age. Nitrogen and phosphorus uptake was lowest in the 40-year-old stand, and highest in the 15- and 5-year-old stand, respectively. Nutrient storage in understorey cardamom was very high: up to 31 % N and 59 % P of the stand total in the 15-year-old stand. Nutrient use efficiency was higher (with faster turnover times) in younger stands and decreased (with slower turnover times) in older plantations. Nitrogen retranslocation showed a strong positive relationship with stand age, while that of P was inversely related to stand age. Nutrient standing stock, uptake and return were also highest in the 15-year-old stand. Nitrogen and P cycling in Alnus-cardamom plantations was functionally balanced. Nutrient cycling and dynamics indicated that Alnus-cardamom plantations performed sustainably up to 15-20 years. The management practice should be altered to incorporate replantation after this age.  (+info)

High genetic diversity in the coat protein and 3 untranslated regions among geographical isolates of Cardamom mosaic virus from south India. (3/9)

A survey was conducted to study the biological and genetic diversity of Cardamom mosaic virus (CdMV) that causes the most widespread disease in the cardamom growing area in the Western Ghats of south India. Six distinct subgroups were derived based on their symptomatology and host range from the sixty isolates collected. The serological variability between the virus isolates was analysed by ELISA and Western blotting. The 3 terminal region consisting of the coat protein (CP) coding sequence and 3 untranslated region (3 UTR) was cloned and sequenced from seven isolates. Sequence comparisons revealed considerable genetic diversity among the isolates in their CP and 3 UTR, making CdMV one of the highly variable members of Potyviridae. The possible occurrence of recombination between the isolates and the movement of the virus in the cardamom tract of south India are discussed.  (+info)

Dietary cardamom inhibits the formation of azoxymethane-induced aberrant crypt foci in mice and reduces COX-2 and iNOS expression in the colon. (4/9)

Recently, considerable attention has been focused on identifying naturally occurring chemopreventive compounds capable of inhibiting, retarding, or reversing the multi-step carcinogenesis. The primary aim of the present study was to identify the effects of a commonly consumed spice, viz., cardamom against azoxymethane (AOM) induced colonic aberrant crypt foci (ACF) in Swiss Albino mice. The secondary aim, was to explore the ability of cardamom to modulate the status of proliferation and apoptosis, and to understand its role in altering cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression. Male Swiss albino mice were injected with AOM (dose: 5mg/Kg body weight) or saline (Group 1) weekly once for two weeks. The AOM-injected mice were randomly assigned to two groups (Groups 2 and 3). While all the groups were on standard lab chow, Group 3 received oral doses of 0.5% cardamom, in aqueous suspension, daily for 8 weeks. Following treatment, significant reduction in the incidences of aberrant crypt foci (p<0.05) was observed. This reduction in ACF was accompanied by suppression of cell proliferation (mean Brdu LI in carcinogen control =13.91+/-3.31, and 0.5% cardamom =2.723+/-0.830) and induction of apoptosis (mean AI in carcinogen control=1.547+/-0.42 and 0.5% cardamom = 6.61+/-0.55). Moreover, reduction of both COX-2 and iNOS expression was also observed. These results suggest that aqueous suspensions of cardamom have protective effects on experimentally induced colon carcinogenesis. Cardamom as a whole and its active components require further attention if the use of this spice is to be recommended for cancer prevention.  (+info)

Inhibition of lipid peroxidation and enhancement of GST activity by cardamom and cinnamon during chemically induced colon carcinogenesis in Swiss albino mice. (5/9)

Globally, colorectal cancer is the third commonest cancer in men since 1975.The present study focuses on the preventive strategies aimed at reducing the incidences and mortality of large bowel cancer. Chemoprevention of colon cancer appears to be a very realistic possibility because various intermediate stages have been identified preceding the development of malignant colonic tumors. Several studies have demonstrated that generous consumption of vegetables reduces the risk of colon cancer. This idea has prompted the present investigation to search for some novel plant products, which may have possible anticarcinogenic activity. It has already been proved from various experiments that chemopreventive agents, by virtue of their anti-oxidant, anti-inflammatory, anti-proliferative, apoptosis-inducing activity, act at various levels including molecular, cellular, tissue and organ levels to interfere with carcinogens. Previous studies from our laboratory have already reported the inhibitory effect of cinnamon and cardamom on azoxymethane induced colon carcinogenesis by virtue of their anti-inflammatory, anti-proliferative and pro-apoptotic activity. This particular experiment was carried out to assess the anti-oxidative potential of these spices. Aqueous suspensions of cinnamon and cardamom have been shown to enhance the level of detoxifying enzyme (GST activity) with simultaneous decrease in lipid peroxidation levels in the treatment groups when compared to that of the carcinogen control group.  (+info)

Domestication of cardamom (Elettaria cardamomum) in Western Ghats, India: divergence in productive traits and a shift in major pollinators. (6/9)

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Activity of essential oils against Bacillus subtilis spores. (7/9)

Alternative methods for controlling bacterial endospore contamination are desired in a range of industries and applications. Attention has recently turned to natural products, such as essential oils, which have sporicidal activity. In this study, a selection of essential oils was investigated to identify those with activity against Bacillus subtilis spores. Spores were exposed to thirteen essential oils, and surviving spores were enumerated. Cardamom, tea tree, and juniper leaf oils were the most effective, reducing the number of viable spores by 3 logs at concentrations above 1%. Sporicidal activity was enhanced at high temperatures (60 degrees C) or longer exposure times (up to one week). Gas chromatography-mass spectrometry analysis identified the components of the active essential oils. However, none of the major oil components exhibited equivalent activity to the whole oils. The fact that oil components, either alone or in combination, did not show the same level of sporicidal activity as the complete oils suggested that minor components may be involved, or that these act synergistically with major components. Scanning electron microscopy was used to examine spores after exposure to essential oils and suggested that leakage of spore contents was the likely mode of sporicidal action. Our data have shown that essential oils exert sporicidal activity and may be useful in applications where bacterial spore reduction is desired.  (+info)

Fumigant toxicity and oviposition deterrency of the essential oil from cardamom, Elettaria cardamomum, against three stored-product insects. (8/9)

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