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81.
82.
This paper discusses the nature and consequences of institutional innovation being pursued in recent years for the organization and management of minor irrigation in Bangladesh. The comparative analysis presented in this paper suggests that there are no significant variations of performance between the mainstream management institutions, except that tubewells under BRDB-Cooperative groups performed less well than others, nor are there any significant associations between major technical factors and irrigation performance (other than nominal pump capacity). What appears to be more important is that the economic institutions such as payment system for water is strongly associated with productivity and equity performance; sharecropping with water, which has emerged, or been popularized, with the privatization programme, has negative impact on productivity and skews benefits of irrigation towards pump owners and managers. It is concluded that so far imperfectly designed institutions, for example privatization of equipment, appear to have failed to give rise to greater technical and allocative efficiency or equity.Abbreviations BADC Bangladesh Agricultural Development Corporation - BRDB Bangladesh Rural Development Board - BKB Bangladesh Krishi (Agricultural) Bank - GB Grameen (Rural) Bank - CARE Cooperative for American Relief Everywhere - KSS Farmers' Cooperative Society - IMP Irrigation Management Programme  相似文献   
83.
An attempt has been made during 2012–2014 at to enumerate the ethno-medicinal evaluation and socio-economic importance of underutilized and unexploited fruits among the Garo tribe of west Garo hills district, Meghalaya, north-east India. The study was based on extensive field surveys, sample collection and interviews with the traditional healers as well as old aged men and women and survey in rural markets regarding their market demand, price and season of availability. Altogether 66 underutilized and unexploited fruits belonging to 34 families have been enumerated in this paper. The documented fruits were mostly used by the rural people to cure a number of ailments. In addition, these fruits also have socio-economic importance in the rural life of the tribal people like use as constructional timbers, firewood, charcoal, fodder, making dye, yielding oil and a number of value added products. Although, these fruits play an important role in the social and cultural life of Garo people, but these valuable species have been vanishing at very faster rate due to lack of proper documentation. Therefore, the claimed therapeutic values of these species are to be critically studied to establish their safety and effectiveness and both in situ and ex situ conservation measures should be immediately undertaken to safeguard the valuable indigenous rural resources of the world.  相似文献   
84.
The effect of different levels of K application on the transformation of native as well as applied Zn fractions in a rice-growing soil was studied under two moisture regimes viz. waterlogged and alternate waterlogged and saturation. Application of K caused an increase in the water-soluble plus exchangeable, organically complexed and carbonates, and other acid-soluble mineral fractions of native soil Zn. Application of K also caused an increase in the transformation of applied Zn into all the above three fractions of the element in soil. The above effects of K were more pronounced in soil under waterlogged than under alternate waterlogged and non-waterlogged moisture regimes. The results of a greenhouse experiment showed that K application caused an increase in Zn uptake and per cent utilization of both native and added Zn by rice. This was attributed to the increase in the water-soluble plus exchangeable and organically complexed forms of Zn in soil due to K application.  相似文献   
85.
Fixation of Zn and Cu applied to tropical rice-growing lateritic soils rich in Fe-oxides may be reduced if the soils are kept flooded for a few days before their application. There may be a further reduction if such flooding is combined with incorporation of green manures. To investigate this effect, a laboratory experiment was conducted to study the effect of different periods (0 and 15 days) of preflooding combined with (0 and 0.50% of soil weight) Sesbania rostrata and Azolla microphylla incorporation as green manures on the transformation of applied Zn and Cu in two lateritic rice-growing soils. Recovery of added Zn/Cu in DTPA (diethylene triamine pentaacetate)-extractable form was always found to be higher when they were applied after the soils were maintained in a flooded state for 15 days than when applied immediately after flooding; this effect was more prominent in respect of Cu. Contrary to expectations, green manure incorporation along with preflooding caused a significant decrease in recovery of Zn/Cu; the effect, however, showed a decreasing trend as incubation progressed. The effect was more marked with A. microphylla than with S. rostrata, particularly with Cu. Possible causes of such changes and their implications on the Zn/Cu nutrition of rice are discussed. Received: 7 August 1995  相似文献   
86.
A field experiment was conducted on sandy loam acidic soil to study the effect of nutrient managements on light interception, photosynthesis, growth, biomass production and yield of Indian mustard [Brassica juncea (L.) Czern & Coss.]. Plant height, number of branches per plant, number of siliqua per plant, number of seeds per siliquae, 1000‐seed weight, seed and oil yield of Indian mustard improved at 100 % recommended rates of NPK (N‐P‐K at 80‐17.2‐33.2 kg ha?1) + 10 t ha?1 farmyard manure (FYM) (T3) compared with 100 % NPK rate (T2). It was also at par with 100 % NPK + 10 kg ha?1 borax + 20 kg ha?1 ZnSO4 (T6) and 50 % NPK + 10 t ha?1 FYM +10 kg ha?1 borax + 20 kg ha?1 ZnSO4 (T10). The rate of photosynthesis increased due to appropriate nutrient management treatments (T3, T6 or T10) with concomitant increase in photosynthetically active radiation, internal CO2 concentration and rate of transpiration and decrease in stomatal resistance. Consequent upon the higher rate of photosynthesis, dry‐matter accumulation increased. The crop receiving nutrient treatment T3 or T6 maintained higher light interception ratio (LIR), leaf area index (LAI), biomass production, crop growth rate (CGR) and net assimilation rate (NAR) that resulted in greater rate of photosynthesis, harvest index and seed yield. Similarly, T10 was equally efficient in registering greater LIR, LAI, CGR, NAR and seed yield of mustard. The average seed yields were 1692, 1683 and 1668 kg ha?1 in T3, T6 and T10, respectively, and these three treatments were significantly superior to T2 (1332 kg ha?1), control (723 kg ha?1) and other treatments. Significantly greater seed oil contents of 41.30, 40.60 and 41.07 % were recorded in T3, T6 and T10, respectively. Thus, significant improvement due to appropriate combination of NPK, FYM, borax and ZnSO4 was observed for uptake of nutrients.  相似文献   
87.
Mean individual fatty acid concentration among differentspecies of the family Cruciferae are not similar because of the presence ofdifferent kind of significant relationship among the individual fatty acids.Brassica napus L., Sinapis alba L.,Raphanus caudatus L.f. Raphanus sativusL. and B. nigra (L.) Koch arecomparatively low erucic acid (<40%) containing species. Crambeabyssinica Hochst. ex. R. E. Fries collections gave as high as 60%erucic acid. Low erucic acid concentration was found associated with thepresence of high level of palmitic and oleic acid concentrations. Erucic acidconcentrations were found varied within the range of 42 to 57% among thecollections of Brassica rapa L. and B.carinata A. Braun. All the collections ofB. nigra (L.) Koch were found to havehigher proportion of linoleic acid than the corresponding oleic acidconcentration. Linolenic acid concentrations of B.nigra (L.) Koch was also higher in comparison to otherspecies of the Cruciferae. Raphanus collections were foundto contain higher levels of total saturated fatty acids as well as eicosenoicacid. Oil content of the total collections under present study did not show anysignificant relationship either with linolenic acid or with erucic acidconcentration. But significant positive relationship was observed between totaloil and erucic acid level within the collections of B.juncea Czern. & Coss. Similarly significant negativecorrelation was observed between total oil and linolenic acid content inBrassica rapa L. ssp. trilocularis (Roxb.) Hanelt, yellow sarson.  相似文献   
88.
The aim of the present study was to investigate the uptake of 16 PAHs by willow (Salix viminalis) from soil amended with contaminated sewage sludge. Uptake experiments were conducted on field plots using sludge applications of 0, 30, 75, 150, 300, and 600 Mg ha?1. The total PAH content of control soil and sludge were 49.6 μg kg?1 and 5713 μ g kg?1, respectively. The concentrations for the 16 PAHs listed as priority pollutants were measured for soil and plant tissue samples obtained at 0.5, 1.5, 2.5, and 3.5 years. Soil total PAH content decreased significantly within the first half year, followed by minimal changes over the subsequent three years of treatment. PAH analysis was carried out on a HPLC-UV. Total PAH content in control plants was 3.6–7.3 μ g kg?1 for shoots and 13–27 μ g kg?1 for leaves. Treated plant tissue content was higher with shoots and leaves containing ~5.5–17.6 and 13.5–33.8 μg kg?1, respectively. Plant total PAH content did not show a significant trend relative to controls with respect to time. However, uptake did increase in relation to an increased sludge application. Bioconcentration factors (BCF), adjusted by control values, were calculated for total PAH content. BCF values were highest for the initial sampling (6 months) and did not show a significant temporal relationship. BCF values did decrease with increasing sludge application. With respect to individual PAHs, elevated plant tissue concentrations were measured for “light” PAH (e.g. naphthalene, phenanthrene, acenaphthalene) with leaf BCF values correlated with solubility and organic partitioning coefficients.  相似文献   
89.
Rooted cuttings of Dendranthema grandiflorum cv. ‘Puja’ were treated with different doses of gamma rays. Sectorial somatic mutations both in flower colour and shape were detected in all the doses. The original floret colour of ‘Puja’ is red‐purple and florets are flat spoon shaped. One of the mutant floret colour was yellow‐orange with original flat florets and another mutant floret colour was yellow‐orange with tubular florets. Original and mutated ray florets were cultured on agar‐solidified Murashige and Skoog basal medium supplemented with sucrose and different combinations of 1‐naphthaleneacetic acid (NAA) and 6‐benzylaminopurine (BAP). Direct shoot organogenesis was seen within 2 weeks of culture initiation. The best regeneration was obtained on medium supplemented with 1 mg/l BAP + 0.5 mg/l NAA. Shoots regenerated from all explant types were rooted in vitro and transferred to the field. Regenerated plants flowered true‐to‐explant floret colour and shape. The isolated yellow floret colour mutants and yellow floret colour mutants with tubular florets were maintained vegetatively and have proved to be true to type in two successive generations.  相似文献   
90.
Sabitri is a rice variety grown in a large part of the rainfed areas of Nepal. It was originally developed for irrigated condition; hence, this variety suffers high yield decline under drought. Two QTLs, qDTY 3.2 and qDTY 12.1 , with large effects on grain yield under drought were identified in the Sabitri background in separate QTL mapping studies. The present study reports the development of Sabitri near isogenic lines (NILs) with combinations of these two QTLs and their characterization under drought. To do so, marker-assisted backcross breeding (MABB) was combined with phenotypic selection to develop high-yielding drought-tolerant NILs with Sabitri grain type. Apart from this, drought-tolerant variants for grain type with high yield under non-stress were identified among the developed NILs. Early days to flowering of up to 13 days and reduction in plant height of up to 13 cm as compared to Sabitri were observed in the developed NILs. Some of these NILs showed higher yield compared to Sabitri and relatively higher tolerance to drought, indicating the capture of positive alleles and interactions during the course of selection. The developed NILs possessed high yield potential which make them suitable materials for the testing of water-saving technologies in irrigated areas. Based on their performance, these NILs can be deployed in rainfed areas in Nepal and other countries of South Asia to increase yield stability.  相似文献   
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