Effect of Substrate/Water Ratio on Biogas Production from the Mixture Substrate of Rice Straw and Salvinia molesta

The substrate/water (S/W) ratio is one of the affecting parameters in anaerobic digestion (AD) since it affects the concentration of total solids (TS) in the biogas feedstocks. The appropriate S/W ratio has to be found to result in a high biogas yield. The goal of this study was to look into the influence of S/W ratio on biogas production from mixture substrate of rice straw and Salvinia molesta. Ratio of S/W was varied to be 1/7 w/v (TS 9.67%w/w), 1/10 w/v (TS 7.52%w/w), 1/13 w/v (TS 6.15%w/w), 1/16 w/v (TS 5.20%w/w). The results showed that S/W of 1/7, 1/10, 1/13, 1/16 resulted a total biogas yield of 22.86, 38.67, 42.71, 43.69 mL/g TS respectively. Decreasing TS from 9.67 %w/w (S/W of 1/7) until 6.15%w/w (S/W of 1/13) could increase the TS removal from 31.03% until 55.66%. However, at TS 5.20%w/w (S/W of 1/16), the TS removal was lower than that at TS 6.15%w/w (S/W of 1/13). The modified Gompertz (R2 = 0.94 – 0.98) can predict evolution of biogas production with higher precision than the first order kinetic (R2 = 0.91 – 0.98). The optimum TS was successfully predicted to become 5.40%w/w.

The impact of raindrops on Salvinia molesta leaves: effects of trichomes and elasticity

The floating leaves of the aquatic fern Salvinia molesta are covered by superhydrophobic hairs (=trichomes) which are shaped like egg-beaters. These trichomes cause high water repellency and stable unwettability if the leaf is immersed. Whereas S. molesta hairs are technically interesting, there remains also the question concerning their biological relevance. S. molesta has its origin in Brazil within a region exposed to intense rainfall which easily penetrates the trichome cover. In this study, drop impact on leaves of S. molesta were analysed using a high-speed camera. The largest portion of the kinetic energy of a rain drop is absorbed by elastic responses of the trichomes and the leaf. Although rain water is mostly repelled, it turned out that the trichomes hamper swift shedding of rain water and some residual water can remain below the ‘egg-beaters’. Drops rolling over the trichomes can, however, ‘suck up’ water trapped beneath the egg-beaters because the energetic state of a drop on top of the trichomes is—on account of the superhydrophobicity of the hairs—much more favourable. The trichomes may therefore be beneficial during intense rainfall, because they absorb some kinetic energy and keep the leaf base mostly free from water.

Environmental and Socio-Economic Impacts of Kariba Weed Infestation of Lakes Kyoga and Kwania, Uganda

The objective of this study was to quantify the coverage of Kariba weed (Salvinia molesta) on lakes Kyoga and Kwania and document the environmental and socio-economic impacts associated with its infestation. Data on weed infestation status was collected in 2017 and compared with pre-infestation period of 2013. Weed infestations were approximately 15,643 and 13,688 ha on lakes Kyoga and Kwania respectively. The infestation impaired fishing activities, water quality, water abstraction and water transport. They also led to 20.4, 60.1, 7.7, 17.6 and 5.7 kg reduction in catches per day for Tilapia, Mukene, Catfish, Nile perch and Mudfish respectively. The infestations were also associated with a general increase in the prices of the fish. Individual fishermen registered losses in fish revenue. Household spent approximately UGX 108,523 annually as treatment costs for diseases associated with weed infestation. While 32% of the respondents tried to manually control the waterweed at approximately UGX 83,988/year, the mobile nature of the weed rendered these efforts unsuccessful. A strategy to sustainably control the waterweed using specific bio-control agents (Cyrtobagous salviniae) is recommended.

Pengaruh Penambahan Tepung Kiambang (Salvinia molesta) Terfermentasi dalam Ransum terhadap Performa Itik Peking

The research was conducted at the Lampung State Polytechnic cage from November to December 2019. This study aims to analyze.The Effect of Adding Leaf Flour (Salvinia molesta )in the Ration on the Performance of Peking Duck. The research method is descriptive method . data collected by taking samples from P0 and P1 with a number of 40 each at the end of maintenance. data obtained were analyzed descriptively. The variables observed were ration consumption resulting in an average P0 (10,213 gr) lower than P1 (10,220 gr), body weight gain P0 (1,324.27 gr) higher than P1 (1,241.53 gr), ration conversion P0 (7,870 ) lower than P1 (8,680), mortality P0 (11%) higher than P1 (3 %)

PKM Introduksi Sediaan Konsentrat Hijauan Rawa Sebagai Sumber Protein Itik Alabio

Duck feed ingredients are currently still expensive and less affordable for breeders, it is necessary to have alternative quality feed ingredients originating from potential superior swamp plants. The activity aims to provide concentrate preparations from swamp forage as feed ingredients for ducks to reduce feed prices, improve ration quality and income (IOFC) for laying ducks. The activity partner is the Keraton duck group in the Martapura sub-district, Banjar Regency. The activity lasts months. The results of this activity are identification of superior forage originating from swamps that have the potential to be used as feed for laying ducks including Kayapu (Azolla pinnata, aquatic algae (Azolla microphylla, duckweed (Lemna minor), water spinach (Ipomoea aquatica Forsk), water hyacinth (Eichhornia crassipes), water hyacinth (Eichhornia crassipes), taro leaves (Colocasia esculenta L.), genjer (Limnocharis flava), kiambang (Salvinia molesta ) and antanan (Centella asiatica (L.) Urban).There are only four forage concentrates that have a nutrient content of more than 20%, namely kayapu , aquatic algae (azolla microphylla), duckweed (Lemna minor) and water spinach (Ipomoea aquatica Forsk), until they are packaged as swamp forage concentrate products .Feeding trial application of alternative feed ingredients, 30% swamp forage concentrate in duck rations can improve the quality of the main duck ration protein (PK), which resulted in an increase in the number of egg production and the percentage of egg production from 67% to 69.3%, as well as a decrease in ration prices from the price before the activity is IDR 5,630/kg to IDR 4,035/kg after the activity. Feed conversion (FCR) was improved from FCR 6.0 improved to 4.6, egg yolk color increased from 8-9 to 10-11, and IOFC increased from Rp 5.8 million/month to Rp 6.3 million/month. The conclusion shows that the activity of making concentrate preparations is very helpful for farmers increase business profits. Keywords: egg production, forage concentrate, iofc, ration price, swamp forage Abstrak Bahan pakan itik saat ini masih mahal dan kurang terjangkau peternak, perlu alternatif bahan pakan yang berkualitas asal tanaman potensial unggulan rawa. Kegiatan bertujuan untuk menyediaan sediaan konsentrat asal hijauan rawa sebagai bahan pakan itik untuk menurunkan harga pakan, memperbaiki kualitas ransum dan pendapatan (IOFC) usaha itik petelur. Mitra kegiatan adalah kelompok itik Keraton di kecamatan martapura Kabupaten Banjar. Kegiatan berlangsung dua bulan. Hasil pelaksanaan kegiatan adalah Identifikasi hijauan unggulan asal rawa yang potensial sebagai pakan itik petelur ada sembilan meliputi kayapu (azolla pinnata, ganggang air (azolla microphylla, duckweed (Lemna minor), kangkung air (Ipomoea aquatica Forsk), eceng gondok (Eichhornia crassipes), daun talas (Colocasia esculenta L.), genjer (Limnocharis flava), kiambang (Salvinia molesta ) dan antanan (Centella asiatica (L.) Urban). Pembuatan konsentrat hijauan hanya ada empat hijauan rawa yang memiliki kadar nutrisi di atas 20% yaitu kayapu, ganggang air (azolla microphylla), duckweed (Lemna minor) dan kangkung air (Ipomoea aquatica Forsk), hingga dikemas sebagai produk konsentrat hijauan rawa. Feeding trial penerapan bahan pakan alternatif konsentrat hijauan rawa 30% dalam ransum itik mampu memperbaiki kualitas ransum itik utamanya protein (PK), yang berdampak pada peningkatan jumlah produksi telur dan prosentase produksi telur dari 67% menjadi 69,3%, serta penurunan harga ransum dari harga sebelum kegiatan sebesar Rp 5.630/kg menjadi Rp 4.035/kg setelah kegiatan. Konversi pakan (FCR) diperbaiki dari FCR 6,0 membaik menjadi 4,6, warna kuning telur meningkat dari 8-9 menjadi 10-11, dan IOFC naik dari Rp 5,8 juta/bln menjadi Rp 6,3 juta/bln. Kesimpulan menunjukkan kegiatan pembuatan sediaan konsentrat sangat membantu peternak meningkatkan keuntungan usaha itik petelur. Kata kunci: harga ransum, hijauan rawa, iofc, konsentrat hijauan, produksi telur

Distribution, ecological and economic impacts and competition of the invasive alien aquatic weeds (Pontederia crassipes Mart., Pistia stratiotes L., Salvinia molesta D.S. Mitch. and Azolla filiculoides Lam.) in Madagascar

In Madagascar, as in several countries in the world, the invasion by four aquatic weeds (Pontederia crassipes Mart. (Pontederiaceae), Pistia stratiotes L. (Araceae), Salvinia molesta D.S. Mitch Salviniaceae) and Azolla filiculoides Lam. (Azollaceae) are among the drivers of environmental and socio-economic deterioration in aquatic ecosystems. Pistia stratiotes was first recorded on the island in the 19th century, and P. crassipes from the beginning of the 20th century, while S. molesta and A. filiculoides were only documented during in the 21st century. From the 1920s, botanists such as Henri Perrier de la Bathie and Raymond Decary were already aware of the dangers caused, in particular by P. crassipes in other countries, and raised the alarm, but little attention has been paid to these species. The aim of the research conducted for this thesis was to determine the distribution, socio-economic and ecological impacts of these four invasive alien aquatic weeds in Madagascar and to make recommendations for their control. First, the distributions of these four aquatic weeds were mapped. This mapping exercise compiled data from different sources including herbarium records, online data and field visits across Madagascar. The mapping study was undertaken from August 2015 to June 2020. Except for mountainous areas above 1800 m (Tsaratanana Massif, Ankaratra Massif and Andringitra Massif) where no data were available, all of Madagascar's bioclimates were invaded by at least one of the four aquatic weeds. In total, at least one species was recorded in 18 of the 22 Regions. Pontederia crassipes was recorded in 13 Regions, S. molesta in 14 Regions, P. stratiotes in 12 Regions, and A. filiculoides in 13 Regions. Herbarium records revealed the oldest record for P. stratiotes to be 1847, 1931 for P. crassipes, 1995 for S. molesta and there were no herbarium specimens for A. filiculoides prior to the start of the current study in 2015. We now know where these four weeds occur and how abundant they are. An objective of this research was to assess the impacts of the four invasive aquatic plants on the socio-economy of the island, mainly on rice production and fishing. Between 2016 and 2019, 102 households in three regions, Soanierana Ivongo, Foulpointe and Antananarivo, were randomly selected and questioned on the impact of these weeds in their aquatic ecosystems and their livelihoods such as fishing and rice growing. Surveys revealed that the four aquatic weeds significantly threatened household activities. On the east coast of Madagascar, the invasions of these four invasive species decreased fish and freshwater shrimp production by 82%. On the high plateau of Madagascar, they reduced rice yield by 30% despite requiring an additional expense of US$ 1,107/ha for control. Although farmers surveyed only used manual control to manage these weeds, they were receptive to other control methods, including integrated control using herbicides and biological control. Another objective of this research was to determine the ecological impacts of the four weeds and specifically if freshwater ecosystem functioning would return after control. To assess the ecological impact, between February 2017 to August 2019, on Lake Antsokafina, the following abiotic and biotic factors were considered: physico-chemistry of water, succession of macrophyte community and animal diversity. With the exception of turbidity, the values of the physico-chemical parameters of the water (pH, electrical conductivity, water temperature and turbidity), were similar between the infested zone and cleared zone. A study on the invasion process of aquatic weeds showed that the plant community succession of the lake changed over time in the areas that had been cleared. The submerged species Ceratophyllum demersum was the pioneer, followed by creeping species such as Echinochloa colona and Ipomoea aquatica, before the area was recolonized by aquatic weeds. Among the aquatic weeds, S. molesta was the most aggressive, covering 92% of the area one year after the start of the experiment. For animal diversity, bird, shrimp and fish community were assessed. The cleaning of the plots in the lake allowed the resumption of fishing activity providing 50 to 200g/catch for shrimp and from 0.25 to 0.5kg/catch for fish per person per day, while no catch was obtained in the areas infested by aquatic weeds were fishermen still attempting to harvest fish/shrimp from the aquatic weed infested areas. Three species of birds, Humblot’s Heron (Ardea humbloti), the white-faced whistling duck (Dendrocygna viduata) and red-billed teal (Anas erythrorhyncha) returned once the areas had been cleared. A manipulated outdoor as descriptor for laboratory experiment was conducted to determine the level and nature of competition of four aquatic weeds species against the indigenous floating fern, Salvinia hastata Desv. (Salviniaceae), using an additive series density model. It was shown that all four invasive species outcompeted S. hastata, with P. crassipes being 24 times more dominant, followed by P. stratiotes at 12 times, S. molesta at 8 times, and finally A. filiculoides at 1.2 times more dominant. This study provided direct evidence of the biodiversity impact of these four species and thus also provided an environmental argument for their control. Based on the findings of this study, a series of recommendations was formulated to manage the invasions of alien species in Madagascar with particular attention to invasive aquatic weeds. These recommendations mainly concern the establishment of management structures and legal instruments such as the creation of a lead government agency at national level and a cross-sectorial invasive species advisory committee, which should review legislation and regulations related to invasive species.

Phytotoxicity of Salvinia molesta in Diesel Exposure

Phytoremediation is one of the methods to remove various types of pollutants from water and soil using plants. Salvinia molesta, an aquatic plant, is chosen in this study to determine its ability to degrade diesel as the pollutant in synthetic wastewater with different diesel concentrations (0, 8,700, 17,400, and 26,100 mg/L) for 14 days. Total petroleum hydrocarbon (TPH) has been used as an indicator to represent diesel concentration variation in wastewater. Degradation of TPH was 85.1% for diesel concentration of 8,700 mg/L, compared with only 53.9% in the corresponding control without plant. While, acute toxicity on S. molesta exposed in diesel concentrations of 17,400 and 26,100 mg/L was observed and eventually had caused the plants to die after 14 days of exposure. Additionally, throughout the phytotoxicity test, the biomass of S. molesta was found to fluctuate confirming inhibition on plant to survive with diesel contaminated water compared with the corresponding control without contaminant. Based on the results obtained it is suggested to decrease diesel concentration less than 8,700 mg/L in future study due to insolubility of diesel in water and the toxicity to the aquatic plants

Field site analysis of giant salvinia nitrogen content and salvinia weevil density

In 2012, a giant salvinia (Salvinia molesta Mitchell) biological control project was initiated in Louisiana. Although similar quantities of salvinia weevils (Cyrtobagous salviniae Calder and Sands) were released at all sites, weevil densities were highly variable among sites. Additionally, signs of plant nitrogen depletion (yellowing plants) were observed at some sites. Because it is well known that plant nutrition can affect the success of a biocontrol agent because of slowed development and/or reduced fecundity, the correlation between giant salvinia nitrogen content and Salvinia weevil density was investigated during the growing seasons of the second and fourth years. During 2013, weevils were reintroduced to sites, and the magnitude of adult weevil density increase varied by site. Giant salvinia nitrogen content varied among sites and sampling dates. Upper Big Break plants had greater nitrogen than all other sites during 75% of sampling dates. Additionally, adult and larval densities were significantly correlated to plant nitrogen content. During 2015, trends were less distinct and weevil densities and nitrogen content varied based on the interaction between sampling date and site, but a significant correlation was not detected. Results from 1-yr of a 2-yr study confirmed published reports of the importance of plant nitrogen content to salvinia weevil productivity. Additional studies are warranted to evaluate and understand the role of nitrogen at giant salvinia biocontrol field sites.