A study of the possible interconversion of hexachlorocyclohexane stereoisomers on chickpea

A field trial was conducted to study (i) whether there is interconversion of stereoisomers of hexachlorocyclohexane (HCH) on a plant and (ii) the rate of dissipation of lindane on chickpea in a sub-tropical climate. The lack of formation of the beta and delta isomers on application of pure alpha- or gamma-HCH showed that these stereoisomers of HCH did not interconvert on chickpea. The residues of the alpha and gamma isomers dissipated rapidly on chickpea leaves with half-lives of three and four days respectively.     

Fern diversity and biomass at Chilapatta reserve forest of West Bengal Terai Duars in sub-humid tropical foothills of Indian eastern Himalayas

We documented the status of fern diversity,biomass and carbon accumulation at Chilapatta Reserve Forest in Cooch Behar Wildlife Division,West Bengal.Stratified random nested quadrat sampling was adopted for analyzing the qualitative and quantitative characters.Nineteen fern species were recorded,of which two are yet to be identified.Identified species were of eight families and nine genera.Highest and lowest frequency recorded were 25.44 and 0.19 while relative frequency varied from 3.16 to 12.25.Fern density ranged from 93 to 13,403 individuals·ha-1.Most of the species were widely distributed.IVI values ranged from 7.54 to 37.45.The above ground portion of ferns accumulated the major portion of biomass and carbon.     

A Comparison of the Temporally Integrated Monitoring of Ecosystems and Adirondack Long-Term Monitoring Programs in the Adirondack Mountain Region of New York

This paper compares lake chemistry in the Adirondack region of New York measured by the Temporally Integrated Monitoring of Ecosystems (TIME) and Adirondack Long-Term Monitoring (ALTM) programs by examining the data from six lakes common to both programs. Both programs were initiated in the early 1990s to track the efficacy of emission reduction policies and to assess the full impacts of acid deposition on surface water chemistry. They now serve to inform on the emerging chemical recovery of these waters. The Adirondack TIME program utilizes a probability-based approach to assess chronic acidification in a population of lakes using one summer sample per year. The ALTM attempts to track changes in both chronic and episodic acidification across a gradient of lake types using monthly samples. The ALTM project has two important attributes that contrast with the TIME program in the Adirondacks: higher temporal resolution (monthly versus once during the summer or fall) and speciation of aluminum. In particular, the ALTM program provides inorganic monomeric aluminum (Al_IM), the fraction of Al that is most toxic. The monthly sampling of the ALTM program includes the spring snowmelt period when acid-neutralizing capacity and pH are near their lowest and Al levels are near their highest. We compare chemistry trends (1992?C2008) for sulfate, nitrate, base cations, dissolved organic carbon, hydrogen ion, acid neutralizing capacity, and Al for the six lakes common to both programs. We also compare relatively high springtime Al_IM concentrations from the ALTM with relatively low summertime total Al concentrations from the TIME, showing that the ALTM program provides a more biologically relevant indicator of the effects of acid deposition, illustrating the value of the complementary monitoring efforts in the Adirondack region.     

Inland saline aquaculture increased carbon accumulation rate and stability in pond sediments under semi-arid climate

Purpose

Similar to fresh- and brackish water aquaculture ponds, commercial shrimp farming in degraded saline areas holds the potential to bury carbon (C) in the sediments. However, studies on the mechanisms of sediment C dynamics and C-flux in response to inland saline aquaculture management practices are still scarce. Therefore, the objectives of the present study are to quantify the C burial rate in inland saline aquaculture ponds and assess the impact of inland saline aquaculture on sensitive C fractions in the bottom sediment of the ponds.

Materials and methods

The sediment samples (n?=?12 from each pond) were collected from six shrimp farming ponds (1000 m² area of each pond) of different ages. The sediment depth, sediment accumulation rate and the levels of total carbon (TC), total organic carbon (TOC) and sediment oxidizable organic carbon (SOC) and its different fractions were determined using standard procedures. The data were analysed by one-way analysis of variance (ANOVA), followed by the Duncan's multiple range test for comparing the means, and the Pearson correlation test was used to assess the relationship between the different pond sediment parameters and SOC content.

Results and discussion

The results revealed that the annual C accumulation rates varied from 902 to 1346 kg C ha^?1 year^?1 in 7-year-old earthen ponds (EPs) and bottom cemented ponds (BCPs), respectively. The sediment C fractions, including TC, TOC, SOC and its fractions (very labile, VLc; labile, Lc; less labile, LLc), and non-labile carbon (NLc)) were progressively increased over the pond age. The inland saline aquaculture practices over the years increased both active (AC) and passive carbon (PC) pools in the pond sediments, helped in the restoration and improvement of sediment quality and enhanced C sequestration potential of the sediments. Furthermore, a significant increase in the level of particulate organic carbon (POC) in BCPs justified that the non-ploughing practices at BCPs facilitated the formation of macro- and micro-aggregates, thereby increasing the C retention and stability of the pond sediments.

Conclusion

This study suggested that the shrimp farming ponds in semi-arid saline soils represented considerable C burial hotspots, enhanced the stable passive C pools and improved the sediment quality.

     

ANTIOXIDANT DEFENSE MECHANISM IN PIGEON PEA UNDER COBALT STRESS

Influence of excess cobalt (Co; 10 to 400 μM Co) on growth, biomass, Co accumulation, photosynthetic pigments, lipid peroxidation, proline, non-protein thiols and cysteine contents as well as activities of anti-oxidative enzymes was studied in pigeon pea (Cajanus cajan Mill). In pigeon pea leaves decreased concentrations of chlorophyll and carotenoids on exposure to excess Co was associated with decrease activity of catalase and super oxide dismutase and suggest antiperoxidative nature of excess Co. However, a marked increase in the activities of ascorbate peroxidase and peroxidase and enhanced levels of cysteine, non-protein thiols, and proline are suggestive of induction of antioxidants in excess Co. The threshold of toxicity (10% growth reduction) and toxicity (33% growth reduction) values of Co in pigeon pea were 75 and 160 μg g^?1in leaves, 42 and 180 μg g^?1in stem and 50 and 340 μg g^?1Co in roots, respectively.     

Are marketing intermediaries exploiting mountain farmers in Nepal? A study based on market price,marketing margin and income distribution analyses

Against the backdrop of viewing marketing intermediaries in developing countries as parasites, this study examined the validity of such a view, especially in the context of mandarin (a species of orange) marketing in a mountain district of Nepal. Necessary information was collected from all major stakeholders such as farmers, collectors and commission agents, and the relative position of farmers in terms of their gains was analyzed by employing three criteria: price of mandarin, marketing margin and income distribution. Income distribution among marketing functionaries “with” and “without” transaction cost has been analyzed. Similarly, marketing margin and farmers’ share of gross income are also analyzed ‘with’ and ‘without’ the cost of malicious practices by marketing intermediaries. Findings of the study revealed that farmers in the study area are receiving a fair share of the benefit accruing from the marketing of mandarin. However, taking advantage of their weak bargaining power and poor economic condition, marketing intermediaries are harassing and cheating them in different ways. Policy recommendations are made to institutionalize and strengthen the group-marketing system to address such inherent problems.     

Biodegradation of beta-cyfluthrin by fungi

Five fungal species, namely, Trichoderma viride strain 5-2, T. viride strain 2211, Aspergillus niger, A. terricola, and Phanerochaete chrysoporium were screened for degradation study of beta-cyfluthrin. Each fungal species was allowed to grow in Czapek dox medium containing beta-cyfluthrin (5 mg/mL) as the major carbon source of the medium. The highest degradation of beta-cyfluthrin was observed by T. viride 5-2 (T(1/2) = 7.07 days), followed by T.viride 2211 (T(1/2) = 10.66 days). The degradation of beta-cyfluthrin followed first-order kinetics with a fast degradation rate during first 7 days of growth of the fungi. In the case of T. viride strain 5-2, five degradation products were isolated after 20 days of growth of the fungi, out of which three products were identified as alpha-cyano-4-fluorobenzyl-3- (2,2-dichlorovinyl)-2,2-dimethyl cyclopropane carboxylate, alpha-cyano-4-fluoro-3-phenoxy benzyl alcohol, and 3(2,2-dichlorovinyl)-2,2-dimethyl cyclopropanoic acid.     

The effectiveness of using a minituber crop for selection of agronomic characters in potato breeding programmes

Summary Performance of 20 potato genotypes was studied for seven agronomic characters in crops raised from minitubers and normal seed tubers. Correlation coefficients were computed between minituber crop and normal seed crop in order to study the selection efficiency at minituber crop level. The performance of normal seed crop was significantly better than the minituber crop for various characters including tuber yield and its components. Correlation coefficients between minituber and normal seed crop were significant for various characters except number of stems and number of tubers. Highest correlation coefficient (r=0.86) was for tuber yield followed by average tuber weight (r=0.67) and number of nodes (r=0.63). The results suggest that selection for tuber yield can be practised at the minituber crop level in potato breeding programmes     

Genetic base of Indian potato selections as revealed by pedigree analysis

Pedigree analysis of the 77 advanced Indian potato selections showed that their origin could be traced to only 49 ancestors out of which 29 were exotic, which accounted for 69.52% of the total genomic constitution and maximum contribution (40.65%) was by 10 ancestors from U.K. Breeders tendency was to involve adapted advanced clones as immediate parents. Coefficient of relationship between pair of selections ranged from 0 to 0.68. The success of the parents used was not related to region-specific choice of parents. The findings are discussed in the context of genetic uniformity and the relevance of having separate breeding programmes for the three major areas of potato cultivation in India. Attempt has also been made to give some directions for choosing selections for use as parents and release as cultivars based on their coefficient of relationship so as to broaden the genetic base of the future potato cultivars.