Biological control of Hydrilla verticillata Vahl by utilization of the grass carp (Ctenopharyngodon idella Vía).
DOI:
https://doi.org/10.15517/am.v7i2.24750Abstract
Hydrilla verticillata has become an important aquatic weed of irrigation canals at some rice farms of Guanacaste, Costa Rica. This species slows water flow, often causing flooding in adjacent roads, its control increases overall production costs. To evaluate efficiency of the grass carp in controlling Hydrilla three trials were conducted, with varying densities of the fish. In the preliminary trial, 987 kg/ha of grass carp reduced Hydrilla biomass in nearly 62 m3 in 21 days. During the second trial, treatments with 1264 and 2042 kg/ha of the fish completely eliminated the weed after 30 days. However, during the third trial, 1000 kg/ha of the carp only reduced Hydrilla volume in 19 m3, after 66 days. The ratio kg of carp/initial volume of Hydrilla proved to be more important than just the kg/ha of the carp. It was observed that when such ratio was lower than 0.02, the carp did not provide a satisfactory control of Hydrilla; on the other hand, a ratio higher than 0.05 significantly reduced the weed's biomass. The equilibrium point between weed regrowth and biomass consumed by the carp occurred at a ratio close to 0.03.
Downloads
References
CASSANI, J.R; CATON, W.E. 1985. Effect of chemical and biological weed control on the ecology of a South Florida Pond. Journal of Aquatic Plant Management. 23:51-58.
HAYNES, R.R. 1988. Reproductive biology of selected aquatic plants. Annals of Missouri Botanical Garden. 75:805-810
JOYCE, J.C.; LANGELAND, K.A.; VAN, T.; VANDIVER, V.V. 1990. Hydrilla, sedimentation and tuber. Aquaphyte. 10(1):3
KLUSSMANN, W.G.; NOBLE, R.L; MARTYN, R.D.; CLARK, W.J.; BETSILL, R.K.; BETTOLI, P.W.; CICHRA, M.F.; CAMPBELL, J.M. 1988. Control of aquatic macrophytes by grass carp in Lake Conroe, Texas, and the effects on the reservoir ecosystem. Texas Agricultural Experiment Station. Department of Wildlife and Fisheries Sciences. Texas A & M University. Texas, U.S.A. 61 p.
SPENCER, D.F.; ANDERSON, L.W. 1986. Photoperiod responses in monoecious and dioecious Hydrilla verticillata. Weed Science. 34: 551-557
SUTTON, D.L.; VANDIVER, V.V. 1986. Grass carp: a fish for biological management of Hydrilla and other aquatic weeds in Florida. Bulletin 86. Florida Agricultural Experiment Stations. Institute of Food and Agricultural Sciences. University of Florida, Gainesville. U.S.A. 10p.
VAN DER ZWEERDE, W. 1990. Biological control of aquatic weeds by means of phytophagous fish. In: Pielerse A.H.& K.J.Murphy (eds.). Aquatic Weeds. Oxford University Press. Inglaterra. pp:201-220
Downloads
Published
How to Cite
Issue
Section
License
1. Proposed policy for open access journals
Authors who publish in this journal accept the following conditions:
a. Authors retain the copyright and assign to the journal the right to the first publication, with the work registered under the attribution, non-commercial and no-derivative license from Creative Commons, which allows third parties to use what has been published as long as they mention the authorship of the work and upon first publication in this journal, the work may not be used for commercial purposes and the publications may not be used to remix, transform or create another work.
b. Authors may enter into additional independent contractual arrangements for the non-exclusive distribution of the version of the article published in this journal (e.g., including it in an institutional repository or publishing it in a book) provided that they clearly indicate that the work was first published in this journal.
c. Authors are permitted and encouraged to publish their work on the Internet (e.g. on institutional or personal pages) before and during the review and publication process, as it may lead to productive exchanges and faster and wider dissemination of published work (see The Effect of Open Access).
