A management strategy for using para grass (Brachiaria mutica) as primary feedstock in a grass carp (Ctenopharyngodon idella) polyculture system | |
| Author | Aguirre, Edwin Marcelo C. |
| Call Number | AIT Thesis no.AE-90-46 |
| Subject(s) | Fishes--Feeding and feeds Carp |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A system of man aging para grass grown on pond enclosures for u se as primary feedstock for a grass carp polyculture system was d eve loped using knowledge and results from tropical pasture research. The objective was a para grass production system in which supply of grass containing at least 2.5% nitrogen (N) was matched to the increasing demand for grass by fish as they grew. The para grass management system included: allocation of small areas at the start with gradual expansion as the fish grew bigger; division of the para grass area into seven small plots for rotational cutting at every twenty one days; and more than two split applications of N up to a total application rate of 800 kg N/ha/year . The system was tested using four 200 m2 ponds, each serving as replicate and each stocked with 200 fingerlings each of grass carp and tilapia (Oreochromis nilotiou s ), 30 common carp (Cyprinus carpio) and 9 snakeheads (Chana striata). Dry matter yields of para grass ranged from 1,300-1,720 kg/ ha/ 2 1 days in the first five cutting cycles to 2,680 -2,860 kg/ ha/2 1 days in the remaining three cycles. The target concentration of 2 . 5% N in t he grass was achieved in five out of eight cutting cycles. Para grass supply generally kept pace with the increasing demand for grass by fish. The extrapolated gross yield of fish obtained was 6,518 kg/ha/year . It was concluded that it is possible to ma n age para grass on pond enclosures relative to the needs of the macrophyte feeding fish and that the system can be tested on - farm for physical and economic feasibility. |
| Year | 1990 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Gartner, Joseph A. |
| Examination Committee(s) | Upasena, Selawa H. ;Knud-Hansen, Christopher F. |
| Scholarship Donor(s) | Government of Australia |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1990 |