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Summary: Hybrid renewable energy systems (HRES) are proving a promising solution for rural electrification in India, where grid power availability is limited. This paper aims to identify the optimal design and pre‐feasibility techno‐economic analysis of the hybrid grid‐independent renewable system for rural electrification. The proposed hybrid system integrates the various renewable energy system configurations to provide continuous power for the electric load demands of Kanakadri palle village, Andhra Pradesh, India. HOMER software is utilized to design the proposed hybrid system, perform optimization, techno‐economic analysis, and simulation. Here, six different hybrid system configurations were taken into account to perform a comparative economic analysis. The results obtained shows that one of the hybrid systems, PV/DG/converter/battery system (120 kW‐PV modules, 54 kW‐DG, 200 number of batteries with 260 Ah ratings, and 50 kW‐power converters), is the least economical optimal system based on least net present cost and Levelized cost of energy (COE), highest renewable fraction, and zero unmet electric loads percentage (NPC: $341 280, COE: $0.217, highest renewable fraction: 96.6% and unmet electric loads: 0%). For the site considered, this optimal hybrid system can provide a reliable power supply to the total energy requirements of 332.97 kWh/d and achieve 75.68% carbon emission reduction compared to a diesel generator. Moreover, the comparison of different system configurations was carried out based on economic analysis. This analysis shows that proposed hybrid system can be an appropriate model to provide reliable power at a low generation cost for the village considered in this study and can be recommended for future electrification projects. [ABSTRACT FROM AUTHOR]

Total Factor Productivity (TFP) measures the growth in output which is not accounted for by inputs. Data Envelopment Analysis which forms the basis for the computation of Malmquist TFP index is used in this paper to study the performance of different river basins in Andhra Pradesh state, India. The results indicated that average technical efficiency of all the basins is only 66%. In all the basins there was a decline in growth of agricultural output during the first two decades, viz., 1979-1980 to 1988-1989 and it had picked in the last decade (1999-2000). All the river basins have TFP change greater than 1 indicating progress in agricultural productivity. Out of the 40 river basins, 14 river basins have technical efficiency change less than 1 indicating decline in TFP growth whereas all the basins have technical changes greater than 1 implying that there is shift in production frontier over years. In general, within the TFP, technical change contributed more than technical efficiency change. Looking at the future options for increasing the agricultural output in the river basins, it is important to focus on improving the TFP growth compared to increasing the quantities of physical inputs. [ABSTRACT FROM AUTHOR]

Shrimp is the most traded food commodity in the world; the majority of it was sourced from farming. Shrimp farmers need to be technically efficient to be globally competitive. We measured the technical efficiency of shrimp farms with a stochastic production frontier to identify the socio‐economic characteristics and input variables that determine it. The model is applied to small‐scale shrimp farmers (n = 150) in Nellore District of Andhra Pradesh, India, by using primary survey data that collected through adopting random sampling with the pretested interview schedule. The average technical efficiency score of 0.95 indicated that the farmers were the most efficient. The finding of the technical efficiency score suggests that strengthening the education, experiences, technological adoption and membership of the society could further enhance the shrimp production about 0.44 tons ha−1 with existing technology and alternating inputs. [ABSTRACT FROM AUTHOR]

A feeding trial was conducted to study the effect of dietary protein (DP) levels on the enzyme activities of different stocks of Macrobrachium rosenbergii juveniles, fed two diets prawn type diets either at optimum (ODP, 32%) or sub‐optimum (SDP, 27%) dietary protein. The activity of key enzymes: glycolysis, gluconeogenesis, amino acid catabolism, pentose phosphate pathway, and energy metabolism was examined on different stocks of M. rosenbergii juveniles in various tissues (muscle, hepatopancreas, and gill). Wild juveniles of M. rosenbergii were collected from the west coast of India, Gujarat (G), Maharashtra (M) and from the east coast of India, Andhra Pradesh (A), and raised in culture ponds of 200 m2 at 1 juvenile m‐2. The experiment was conducted for a period of 60 days. A Visible Implant Elastomer (VIE) Tag was injected into different prawn juveniles' stocks A, (3.06–3.10 g), M, (0.80–1.01 g) and G (0.90–1.06 g) for the individual identification of each class. All the animals were acclimatized for 7 days before being released into the pond. Each of the two diets, the first with 27% SDP, termed the sub‐optimum level (S), and the second 32% DP, termed the optimum level (O), was fed in triplicate ponds. The weight gain of stocked prawn was significantly higher for G stock (3.03 ± 0.18 g) compared to M stock (2.53 ± 0.25 g) and A stock (1.33 ± 0.10 g). In addition weight gain in ODP was significantly higher (3.05 ± 0.22 g) compared to SDP (2.11 ± 0.17 g). Furthermore, both protein level and stock type had a significant (p ≤ 0.05) effect on the survival rate, specific growth rate, and feed conversion ratio of the prawn. A significant interaction was recorded between metabolic enzyme activities and the variation of dietary protein levels and differences in M. rosenbergii stocks, in which stock "G" and "M" exhibited healthier enzyme physiological status than stock "A". The findings presented here may conclude that the enzymes quickly respond to dietary protein manipulations of cultured shrimp. The results can be useful in identifying the optimum stock (genotypes) in a given culture condition and subsequently higher production may be achieved. [ABSTRACT FROM AUTHOR]

Freshwater prawn production in India that includes farming and wild capture of the giant freshwater prawn, Macrobrachium rosenbergii and the monsoon river prawn, M. malcolmsonii has increased steadily since 1999 reaching a peak output of 42 780 t in 2005, but then declined to 6568 t in 2009-2010. Stunted growth and diseases in ponds because of poor seed quality and the broodstock which had been inbred over several generations; pond water quality issues; and increased cost of production on account of feed, labour and the mandatory certification requirements are suggested to be some of the factors leading to the production declines. While majority of the output occurs in Andhra Pradesh, single crop paddy-prawn production systems in the low-lying fields of Kerala have helped gradual transformation to a sustainable, organic mode of farming of both rice and prawns, suitable for other states of India. Although the trends by June 2011 indicate that the sector is set to a revival, future prospects of freshwater prawn farming in India will also depend on the expansion of whiteleg shrimp Litopenaeus vannamei that was introduced recently in India and provided a more profitable opportunity for farming. [ABSTRACT FROM AUTHOR]

A feeding trial was conducted to study the effect of dietary protein (DP) levels on the growth and digestive enzyme activities of different wild stocks of Macrobrachium rosenbergii juveniles. Wild juveniles of M. rosenbergii were collected from the west coast of India, Gujarat (G), Maharashtra (M) and from the east coast of India, Andhra Pradesh (A), and raised in culture ponds of 200 m2 at 1 juvenile m−2. All the animals were tagged individually with Elastomer tags of a particular colour assigned to their respective stock and acclimatized for 7 days before being released into the pond at a ratio of 70:65:65 (A:M:G). Each of the two feeds, the first with 27% DP, termed the suboptimum level (S), and the second 32% DP, termed the optimum level (O), was fed in duplicate ponds at 6% of the body mass for the first 30 days and 4% for the last 30 days. The average weight of stocked prawn, respectively, in O DP and S DP fed ponds was 0.90 ± 0.04 and 1.06 ± 0.08 g for the G stock, 0.80 ± 0.07 and 1.01 ± 0.1 g for the M stock and 3.06 ± 0.13 and 3.10 ± 0.23 g for the A stock. Both the protein level and the stock type had a significant ( P<0.05) effect on the weight gain% of the prawn. There was an approximate 95% change in weight gain with a DP change. Similarly, G and M stocks exhibited significantly higher ( P<0.05) growth rates of approximately 90% than the A stock, although no difference was noted between the G and the M stocks. However, for protein × stock (interaction) levels, there was no significant difference ( P>0.05) among the groups. Although insignificant, the survival rates among the different stocks varied from 56% to 77%. Optimum protein level showed a significant increase ( P<0.05) in the specific growth rate (SGR). Feed conversion ratio, feed efficiency ratio, protein efficiency ratio and net protein utilization were not affected either due to DP, stock type or their interaction. The O × A group exhibited the maximum variation in body weight. Digestive enzyme activities were similar in all the groups, but enzymes for phospho-monoesterase were significantly higher ( P<0.05) at O DP. Both the G and the M stock showed a significantly higher ( P<0.05) alkaline phosphatase activity while acid phosphatase activity was significantly higher ( P<0.05) in the M stock only. Overall, the G and M stocks showed higher growth responses compared with the A stock. [ABSTRACT FROM AUTHOR]

AbstractThree major carp species, viz. catla Catla catla (Hamilton-Buchanan), Labeo rohita (Hamilton) and mrigal Cirrhinus mrigala (Hamilton), are farmed in polyculture systems in the southern state of Andhra Pradesh (15–18°N, 77–80°E), India. A survey of 189 carp farms was undertaken, and principal component analysis was used to assess the relationship(s) between farm inputs and fish yield. Model results exhibited a strong relationship of yield with the stocking density of all three major carp species (rohu, catla and mrigal). Similarly, buffalo manure, poultry droppings and groundnut oil cake, representing use of major organic fertilizers, also contributed to high yields. Also, supply of supplementary feed ingredients, such as groundnut cake, cottonseed meal, deoiled bran and sunflower meal, and additives in the feed, such as salt and mineral mix, had a positive influence on the yield. The management inputs that influenced the yield were rate of water exchange, frequency of medication and age and mean weight of fingerlings at stocking. Furthermore, the analysis indicated that older ponds were more productive. It was observed that inorganic fertilizers and a few feed ingredients have a secondary and/or a tertiary role in the system, indirectly influencing production. Intrinsic variables, such as age of the farmer and literacy rate, were linked with the less important components, suggesting that the socio-economic variables had a less prominent role in influencing the yields once a production decision was made. [ABSTRACT FROM AUTHOR]