4 - Central Institute of Brackishwater Aquaculture

National Workshop-cum-Tratnlng on Bioinformatlcs and Information Management in Aquaculture
2. Data and variables
2.1. Data sources
The present analysis was carried out on a data set of 221 aquaculture farms that
was collected using multistage stratified random sampling covering 73 revenue
villages spread over 9 Mandals of West Godavari and Krishna districts of Andhra
Pradesh under the AP-Cess fund project entitled "Technological innovations in
aquaculture and its effects on sustainability of farming systems in Andhra
Pradesh" funded by Indian Council of Agricultural Research (ICAR) during 1998-
2002. Farmers of Kolleru Lake generally practice semi-intensive composite
culture of two Indian major carps namely catla (Catla catla) and rohu (Labeo
rohita) at a species ratio of 1:4 and at a stocking density ranging from 5 - 10
thousand advanced fingerling/ha with higher level of input recommended for
composite fish culture adopting single stocking and single harvesting techniques.
The earlier practice of five species poly culture of carps (IMC and exotic) is now
replaced by a two species (Rohu and Catla) culture system (Padmavathi and
Prasad 2003). This technology is the modified version of composite fish culture
technology (Chaudhuri et a1.1975) that the farmers of Kolleru Lake area have
perfected with respect to species composition and input use, which were driven
by growth of cultivable species, market demand, consumer preference, keeping
quality and economics. The technology delivers a yield of 7-15 tones/ha/yr.
2.2. Input and output variables
All input and output variables used in the stochastic frontier production function
model in this study are clearly defined along with measurement units (Table 1).
Summary statistics of organic manure, inorganic fertilizer, lime, chemicals and
drugs, feed applied, types of labor engaged and socio-economic profiles like
religion, caste, age, no. of children, education, experience, asset, etc. of the
farm operators are furnished in table-2.
2.3. Sample Characteristics
The average pond size of our sample was 8.7 ha and the range was 0.8 - 61 ha.
The primary occupation of 79% of the farmers is aquaculture. 96% of the
farmers receive water from the adjoining irrigation canals and 4% take water
from natural sources. 92% of the farmers are facility owners or survey revealed
that 83% farmers reported renovating now often their ponds as part of pond
management practices. All farmers cultured catla and rohu at a species ratio of
1:4 and at an average stocking biomass of 1939 kg/ha. Single stocking and
single harvesting practices per year was resorted to by 95% of the farmers. Feed
97% of farmers applies was using perforated bags hanged from poles and
submerged. Average yield of fish was 10.63 t/ha/year.
3. Empirical Model for Estimation of Technical Efficiency and Test of
Hypothesis
It is mentioned that the level of technical efficiency of a particular farm is
characterized by the relationship between observed production and some ideal
production (Greene, 1993). The frontier production function defines potential