Unravelling the diversity and assemblage of phytoplankton in homestead ponds of central coastal belt,Bangladesh

Homestead ponds may offer an ideal opportunity in contribution to household income, fish consumption through fish culture. Phytoplankton plays a key indicator in pond productivity. However, the phytoplankton communities in the homestead ponds are nearly undetermined in Bangladesh. This study summarizes the phytoplankton diversity, assemblage and ecological parameters of the homestead ponds in central coastal belt, Bangladesh, based on two seasons. The results revealed that significant differences (p < .05) were found in pH, DO, conductivity, TDS, nitrates, phosphates and sulphates except temperature in monsoon, and transparency in both seasons. A total of 34 phytoplankton genera representatives of five major groups were recorded such as Euglenophyceae (41.5%), Chlorophyceae (30.5%), Cyanophyceae (13%), Dinophyceae (10%) and Bacillariophyceae (5%). A significant difference (p < .05) in phytoplankton abundance was found in both seasons with the highest mean of 186.13 ± 129.34 × 10⁴ cells L^?1 in monsoon and the lowest mean of 144.40 ± 107.26 × 10⁴ cells L^?1 during winter. The diversity (H'), evenness (J'), richness (d) and dominance (D) ranged from 1.62 to 2.47, 0.52 to 0.97, 0.37 to 1.15 and 0.10 to 0.28 respectively. Based on SIMPER, the most dominant (>10%) genera for dissimilation within stations and seasons were Euglena spp., Phacus spp., Chlorella spp., Strombomonas spp. and Peridinium spp. ANOSIM results stated that 12 genera of phytoplankton were significant contributors based on average dissimilarity. Pearson's correlation coefficient and canonical correspondence analysis (CCA) revealed that phytoplankton abundance, diversity and community were mainly governed by transparency, dissolved oxygen and nitrates.     

Economics and Employment Generation of Bamboo-Based Enterprises: A Case Study from Eastern Bangladesh

An exploratory survey was carried out to assess economics and employment generation of the trade of bamboo and bamboo-based secondary products in the eastern Bangladesh, to obtain reliable information about their status, socio-economic significance, production and marketing. The study was undertaken over 30 bamboo-based enterprises in a suburban market of eastern Bangladesh, to investigate regional product details, economic profitability and employment opportunities. The sample entrepreneurs, corresponding to about 25% of the bamboo enterprise population were interviewed using a semi-structured questionnaire. About 202 full and part-time workers were employed in the factories, under categories of artisan (who manufactured secondary products). The average number of worker’s in the large, medium and small factories were 9 (artisan 40%), 6.45 (artisan 35%) and 5 (artisan 25%) respectively. The study revealed that there was always a satisfied demand of skilled artisans. Most of the workers were relatively newly employed (not more than 5 years). The daily wage rate varied between 70 and 130 Tk. ($US 1 equals approximately 70 Bangladeshi Taka (Tk.), as at December 2008). Bambusa balcooa was the most utilized species (39.96%) in terms of monetary value. The price of a single B. balcooa culm in the local market was Tk. 160–210. Nine sizes of articles under seven bamboo categories were identified, these being bera (36″ × 120″ and 72″ × 96″), bookshelf (36″ × 24″), chaluni (12″ × 12″), chatai (48″ × 60″ and 36″ × 48″), jhuri, rickshaw hood and tukri. Net average profit per article was the highest for rickshaw hoods (Tk. 400 at the retailer stage). The total expected annual income for an enterprises from all articles types sold was estimated to be Tk. 85,800. Three distinct marketing channels were identified for selling bamboo and value-added secondary products. The study also generated policy implications for effective management of bamboo-based enterprises.     

Differential recovery of lupin proteins from the gluten matrix in lupin-wheat bread as revealed by mass spectrometry and two-dimensional electrophoresis

Bread made from a mixture of wheat and lupin flour possesses a number of health benefits. The addition of lupin flour to wheat flour during breadmaking has major effects on bread properties. The present study investigated the lupin and wheat flour protein interactions during the breadmaking process including dough formation and baking by using proteomics research technologies including MS/MS to identify the proteins. Results revealed that qualitatively most proteins from both lupin and wheat flour remained unchanged after baking as per electrophoretic behavior, whereas some were incorporated into the bread gluten matrix and became unextractable. Most of the lupin α-conglutins could be readily extracted from the lupin-wheat bread even at low salt and nonreducing/nondenaturing extraction conditions. In contrast, most of the β-conglutins lost extractability, suggesting that they were trapped in the bread gluten matrix. The higher thermal stability of α-conglutins compared to β-conglutins is speculated to account for this difference.     

Phosphorus–microbes interaction on growth,yield and phosphorus-use efficiency of irrigated cotton

The phosphorus-use efficiency of crops in high pH soil is low. A randomized complete block design in a 3 × 2 split-plot experiment was conducted on a high pH silt loam (Typic Ustochrepts) to evaluate whether P-solubilizing microbial (PSM) inocula were able to improve the P fertilization effects on irrigated cotton (Gossypium hirsutum L., cultivar CIM-482). Cotton was planted after seed treatment with PSM inoculation at 0, 22 and 44 kg P ha^?1. Results showed that soil microbial populations were significantly higher throughout the cotton-growing season in response to P fertilization and PSM inoculation. Both P fertilization and PSM inocula exerted a significant effect on cotton biomass and Puptake without an interaction. Economic analyses suggest that PSM inocula alone significantly increased P-use efficiency (8%), reduced cost and improved net income (by $36 ha^?1) of irrigated cotton production. Moreover, the relationship between relative yield and P fertilization with PSM inocula showed that 95% of the maximum yield of cotton was produced at 22 kg P ha^?1, whereas in the absence of PSM inocula, 95% relative yield was obtained at 36 kg P ha^?1, asaving of ～39% applied P with PSM inoculation.     

Long-term productivity growth and sustainability of Greek irrigated agriculture

The present study examines the long-term productivity growth and sustainability of Greek irrigated agriculture. A log linear trend model was used to measure long-term productivity growth, and the total factor productivity (TFP) approach measures the sustainability of the irrigated production system. A time series database of inputs and outputs data were used for the production period of 1961?–?2001 (41 years) which revealed that there is an increasing trend in the irrigated area of the country. The annual growth rate of the irrigated area is 2.6% during this time period. The long-term trends in yields of crops grown in irrigated agriculture are positive. Fertilizer use rate per ha sharply increases during this period. The productivity of irrigated Greek agriculture also increases over the time period as a result of the introduction of High Yielding Variety (HYV), seed, fertilizer and water technology. The measurement of TFP indices indicates that the long-term trend in productivity growth of irrigated Greek agricultural system is positive. The result implies that the irrigated Greek agricultural production system has long-term sustainability. The result also indicates that fertilizer, fixed capital, rainfall and temperature are positively contributing to the mean production of Greek irrigated agriculture. On the other hand, pesticide, labour and fixed capital reduces variability of irrigated agriculture. To this end, long-term agricultural sustainability depends on patterns of input use.     

Fertilizer use efficiency of drought-stressed oat (Avena sativa L.) following soil amendment with a water-saving superabsorbent polymer

Abstract

In arid and semiarid regions of northern China, there is an increasing interest in using reduced rates of chemical fertilizer along with water-saving superabsorbent polymer for field crop production. Field experiments were conducted during the year 2009 and 2010 to study the growth performance and yield characteristics of forage oat (Avena sativa L.) as well as soil moisture and nutrient status of the experimental field under different fertilizer (standard, 300; medium, 225; and low, 150 kg ha^?1) treatments with (60 kg ha^?1) or without application of superabsorbent polymer. Our results show that above-ground biomass accumulation fell by 14.8% under medium and 32.6% under low fertilizer levels whereas application of superabsorbent polymer increased it significantly by 39.7%. Similarly plant height, tiller fertility rate, grain yield, relative water content in the leaves as well as quality of forage also increased for superabsorbent polymer treatment. Considering the trends of growth reduction (qualitative and quantitative) due to fertilizer reduction and progressive influence of superabsorbent polymer on those parameters, it was clear that application of superabsorbent polymer plus only half the conventional fertilizer rate (150 kg ha^?1) would be a more appropriate practice for forage oat production under arid and semiarid conditions of northern China or in areas with similar ecologies.     

Host preference and influence of the sweetpotato whitefly,Bemisia tabaci (Homoptera: Aleyrodidae) on eggplant (Solanum melongena L.)

Abstract

Three eggplant (Solanum melongena L.) varieties – ‘Dafeng’, ‘Beisite’, and ‘Baiyu’ – were used in this experiment to discover the least susceptible variety among them to sweetpotato whitefly (Bemisia tabaci) infestation. The investigations were carried out after completing one generation of whitefly based on two points of view. Initially, host preference and suitability of whitefly was investigated based on adult feeding, oviposition, and developmental time. Therefore, it was investigated based on growth responses of eggplant. The average developmental time was shortest for the cohort reared in ‘Dafeng’ (21.3 days), while the longest period (23.2 days) was recorded in ‘Baiyu’. In comparison with the control, less significant changes in the six growth parameters, viz. plant height (12.6%), leaf area (12.7%), dry matter (8.2%), absolute growth rate (26.0%), relative growth rate (25.0%), and net assimilation rate (22.2%) were found in ‘Baiyu’ infested by B. tabaci. Adult attraction and oviposition were reduced while developmental time was increased in ‘Baiyu’ compared with the other two varieties. In addition, the reduction percentages of all the six plant-growth parameters of ‘Baiyu’ were comparatively less than other two varieties to whitefly stress. Our research is focused on a shorter development time; higher feeding, oviposition, and the reduction percentage of plant growth indicate that a plant is a suitable host. In view of this, the present findings indicate that ‘Baiyu’ is less susceptible than the other two varieties, ‘Dafeng’ and ‘Beisite’, for whitefly infestation.     

Effects of Zinc on Root Morphology and Antioxidant Adaptations of Cadmium-Treated Sedum alfredii H.

ABSTRACT

The study demonstrated S. alfredii is an excellent cadmium (Cd)/zinc (Zn) hyperaccumulator as Cd and Zn concentrations in leaves reached 2,183 and 13,799 mg kg^?1 DW, respectively. There was a significant increase in root morphological parameters induced by 50 and 500 μM Zn supplement; however, a sharp decrease in these parameters occurred when treated with 100 μM Cd +1000 μM Zn. The inhibited root dehydrogenase activity in 100 μM Cd treated plants was restored to control levels when supplemented with 500 μM Zn. Moderate Zn supplement did not produce significant changes in (malondialdehyde) MDA concentrations as compared with those treated with Cd alone. Variations of the antioxidative enzymes proved an ineffective role in coping with metal-stress in S. alfredii. Combined Cd and Zn treatment significantly enhanced ascorbic acid (AsA) and glutathione (GSH) contents in leaves of S. alfredii, as compared with those treated with Cd alone. Thus, Zn may rely on the involvement of GSH in detoxification and tolerance.     

QUARTZ PORPHYRY TREATMENT ALTERS IRRIGATION WATER CHEMISTRY,AFFECTING HYDROPONIC VEGETABLE PRODUCTION

This study focused on using quartz porphyry (QP) as a water treatment to improve hydroponic production of komatsuna (Brassica rapa L. nothovar; Japanese mustard spinach). We compared the chemistries of the control and QP-treated nutrient solutions and found that magnesium (Mg²⁺) and calcium (Ca²⁺) concentrations increased linearly up to day 21 following sowing in both conditions, then declined slightly. The QP treatment reduced sodium (Na⁺) and chloride (Cl^?) concentrations for the whole cultivation period. In both the control and QP-treated solutions, nitrate (NO^? ₃) and sulfate (SO^2? ₄) showed the same trend to a daily increase. In spite of these similarities, however, komatsuna production was better with the QP-treated nutrient solution compared to control. Treatment with QP during cultivation in August–September reduced the harmful effects of Na⁺, chloride (Cl^?), nitrite (NO^? ₂), and SO^2? ₄ by reducing concentrations of these ions, possibly leading to decreased salinity and toxicity effects in the plants. Mineral concentrations during October–November differed from those of August/September, resulting in variation among the different growth parameters for komatsuna.