Performance and costs of grass carp in controlling aquatic weeds compared to mechanical control in some Egyptian canals (case study) (Published)
During the recent years, biological weed control in Egypt has faced questioning for its ability to submerged weeds control; and its application does not reduce the costs of canals maintenance. Therefore, the study aims to verify the performance and costs of grass carp in controlling submerged aquatic weeds and compared to mechanical control in some earthen and lined canals in Aswan governorate. Six earthen and lined canals with a high rate of submerged aquatic weeds growth were selected in the irrigation administration of Aswan governorate. The results of the study showed that the biological control of submerged weeds by grass carp led to decrease the percentage of submerged weeds infestation in the canals that subjected to biological control compared to the similar canals that subjected to mechanical control. Grass carp prefer to feed on submerged aquatic weeds types in the studied canals as follows: Vallisneria spiralis, followed by Ceratophyllum demersum and finally Myriophyllum spicatum. The value of the condition factor for grass carp was above 1, indicated good condition of the fish growth. Water quality was good and valid for grass carp growth. The average decreasing in the costs per kilometer for the canals and reaches that subjected to biological weed control was 7880 LE, with a decreasing percentage of 38% compared to mechanical control. It is recommended to control submerged aquatic weeds using grass carp in suitable Egyptian canals through applying an integrated management program. The program is combination of mechanical removal process of weed a one-time before stocking fish, then, stocking rates of 100 kg/ha.
As a result of increasing population growth and urbanization, there is a high and increasing demand for rice, this necessitates the high attention for its production. This research was conducted to determine the profitability considering the cost and returns of paddy rice production in Chikun Local Government Area of Kaduna State. Data for the study were collected from 60 randomly selected paddy rice farmers using a well structured questionnaire and analyzed using the descriptive statistics, the gross margin and net income model. The result showed that 97% were male, 88% married and had an average household size of 10people. It was interesting to realize that all respondents had one form of education or the other and their average farm size was 15ha producing about 3.2tonnes of paddy per hectare. The average variable cost incurred per hectare was estimated to be $866.3 (N172,400) while the total cost of production was put at $1002 (N199,400) and a gross revenue of $1768.84 ( N352,000) was generated. Paddy rice production in the study area was estimated to have a gross profit $902.51 (N179,600) and a net returns of $766.83 (N152,600). The study however concluded that paddy rice production in the study area is a profitable enterprise and it also recommended that consistent government policies that would favour increase in paddy production, market information, extension service delivery, input subsidization and credit facilities be implemented.