Weed invasions countered by biological control: Salvinia molesta and Eichhornia crassipes in Sri Lanka

1992 ◽  
Vol 42 (2) ◽  
pp. 99-107 ◽  
Author(s):  
P.M. Room ◽  
I.V.S. Fernando
CORD ◽  
2017 ◽  
Vol 33 (1) ◽  
pp. 15
Author(s):  
S.H.S. Senarathne

Aquatic weeds cause severe productivity loss in agriculture. These plants invade lakes, ponds, rivers, canals and agricultural fields, becoming noxious weeds. The study was conducted at the vermicomposting unit of the Coconut Research Institute, Lunuwila, in the Low country Dry Zone of North Western province of Sri Lanka from August 2012 to May 2013 to find out the feasibility of producing vermicompost from three aquatic weeds; Salvinia molesta, Eichhornia crassipes and Lagenandra toxicaria. Vermicompost and compost were prepared separately from aquatic weeds and Gliricidia and Guinea grass combinations. During the vermicomposting process, growth parameters of earthworms; number of earthworms, was taken in every ten days interval further, physical, chemical and biological properties of compost and vermicompost were analyzed. Experiment was carried out in a Complete Randomized Design (CRD) with eight treatment and five replicates in each treatment. Eichhornia and Salvinia recorded the highest adult earthworm number and juvenile number with the lowest mortality rate. Electrical conductivity (6.75 dSm-1), organic carbon (13.21%), phosphorous (3.61%), potassium (5.03%) and calcium (6.12%) were significantly high in Lagenandra toxicaria, Gliricidia and Guinea grass treatment was significantly high in nitrogen content (3.93%) and low in C: N ratio (2.51), compared to aquatic weeds. Salvinia showed comparatively higher nitrogen content and lower C: N ratio among aquatic weeds. Both Eichhornia and Lagenandra showed significantly higher microbial activity. Vermicompost was superior in all the properties compared to compost in the same substrate. The study revealed that aquatic weeds such as Salvinia molesta, Eichhornia crassipes and Lagenandra toxicaria which are readily available in the coconut triangle can be successfully used to produce Vermicompost. It can be concluded that the Vermicompost produced from aquatic weeds locally could be a suitable organic fertilizer for organic coconut farming in Sri Lanka.


2007 ◽  
Vol 17 (8) ◽  
pp. 773-795 ◽  
Author(s):  
Daya Ahangama ◽  
Frank E. Gilstrap
Keyword(s):  

2017 ◽  
Vol 6 (1) ◽  
pp. 23-30
Author(s):  
N. N. Punchihewa ◽  
S. R. Krishnarajah ◽  
P. Vinobaba

Mysids are one of the most abundant and important fauna in estuarine hyperbenthic communities. They form important links in estuarine food chains and play a critical role in the cycling of energy within estuarine systems. Therefore, it is important to recognize the distribution of estuarine mysids in Sri Lanka. The present study was undertaken in Bolgoda estuarine system and Lunawa lagoon, in order to find out the distribution of mysids in these brackish water systems. Reconnaissance surveys were conducted, in Bolgoda North Lake, Panadura estuary of the Bolgoda estuarine system and the Lunawa lagoon from April 2012 to February 2013. The samples were collected using a hand held dip net, during day time at low tide along an eighty meter transect at the boundary of the estuarine waters. Mesopodopsis zeylanica was the only mysid species observed from the low water areas of the lagoon along the boundary of the stream. In each collection, it was recorded, higher percentages of females than the males. Mysids were recoded only from unpolluted areas and they were absent, where Eichhornia crassipes (water hyacinth) was widespread. The findings of this analysis could be used to establish the fact that boundary condition and polluted condition are having a great effect on presence of mysids. It may be due to their specific niche requirements and specialized habitats. Accordingly, mysids serve as pollution indicator species in estuarine ecosystems. An immediate management strategy is required in protecting the Bolgoda estuarine systems from dumping household pollutants as well as other pollutants and complete elimination of the invader plants like E. crassipes, in order to protect estuarine biodiversity.INTERNATIONAL JOURNAL OF ENVIRONMENT  Volume-6, Issue-1, Dec-Feb 2016/17, page: 23-30


2020 ◽  
Vol 6 (2) ◽  
pp. 149-159
Author(s):  
Ummi Suraya

The aim of this research is to identify and to inventory water plants in Hanjalutung Lake,Petuk Ketimpun Village, Jekan Raya District, Palangka Raya City. This research was conducted from December 2017 to January 2018. Sampling was carried out in 3 (three) stations, namely inlet ,middle and outlet. The tool used for aquatic plants 2 x 2 m transect.The results of research aquatic plants found in the waters of Lake Hanjalutung 7 (seven) types namely Kiambang (Salvinia molesta), gerigit/bite (Leersia hexandra), Cat Tail Grass (Utricularia aurea), Para Grass (Cyperus platystylis), Water Hyacinth ( Eichhornia crassipes ), Kiapu (Pistia stratiotes) dan Ketanan (Polygonum sp).


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