Paspalum Conjugatum Research Articles

The effectiveness of isopropylamine glyphosate 486 g/L + metsulfuron methyl 1 g/L herbicidal combination in oil palm (Elaeis guineensis)

Lack of knowledge in weed control techniques in oil palm cultivation practices can lead to decreased productivity. One of the herbicides that can be used to control weeds in oil palm cultivation is a mixed herbicide made from isopropylamine glyphosate 486 g/L and methyl metsulfuron 1 g/L. The use of mixed herbicides with two or more active ingredients can broaden the spectrum of weed control, reduce herbicide residues, slow the emergence of herbicide-resistant weeds, and reduce production costs. Therefore, this study aims to determine the effectiveness of mixed herbicides IPA glyphosate 486 g/L and methyl metsulfuron 1 g/L in controlling weeds in oil palm plants in the producing phase. This research was conducted at Bukit Nyomot oil palm plantation Subang Regency, Jawa Barat Province from February to May 2023. The experimental design used was Randomized Complete Block Design (RCBD) with 6 treatments and each treatment was replicate 4 times. The treatments are consisted of the application of mixed herbicides IPA glyphosate 486 g/L and methyl metsulfuron 1 g/L at doses of 1 L/ha; 1.5 L/ha; 2 L/ha; 2.5 L/ha; manual weeding; and control (no treatment). The results shows that the mixed herbicide IPA glyphosate 486 g/L and methyl metsulfuron 1 g/L at a dose of 1 L/ha to 2.5 l/ha is effective in controlling weeds in oil palm, such as Paspalum conjugatum, Ottochloa nodosa, Asystasia intrusa, Ageratum conyzoides, Chromolaena odorata, other weeds, and total weeds up to 12 Weeks After Application (WAA).

Evaluation of the suitability of three weed species as alternative cover crops in smallholder oil palm plantations through plant spacing management

Smallholder oil palm plantations in Indonesia have reached 8.9 million ha, but their role is still not optimal due to low productivity caused by the lack of knowledge of smallholders regarding sustainable oil palm technical culture, such as the use of cover crops. However, it requires appropriate spacing for different species. This study aims to obtain the optimum spacing of 3 weed species planted as cover crops in smallholder oil palm plantations. The research was carried out in 2022 at the smallholder oil palm plantation Naga Rejo village, Galang, Sumatera Utara, Indonesia. The experimental treatments included weed species (Asystasia gangetica, Paspalum conjugatum and Nephrolepis biserrata) as the main plot and spacing (10, 20 and 30 cm) as subplots arranged in a separate plot design with 3 replications. The results showed that the % of 100% land coverage was obtained in plantings of N. biserrata and A. gangetica in 4 WAPs and 10 cm spacing in 3 WAPs independently. The highest leaf area of N. biserrata, P. conjugatum and A. gangetica was obtained at a spacing of 30 cm. The highest dry weight, growth rate and nutrient uptake N and K N. biserrata and P. conjugatum were obtained at a spacing of 10 cm, while A. gangetica at a spacing of 30 cm. This shows that the optimum spacing depends on the weed species. The optimum spacing for A. gangetica (broad leaf) is 30 cm, while for P. conjugatum (grasses) and N. biserrata (ferns) is 10 cm.

First Report of Angiopsora paspalicola Causing Leaf Rust on Paspalum conjugatum in Malaysia.

Paspalum conjugatum (family Poaceae), locally known as Buffalo grass, is a perennial weed that can be found in rice field, residential lawn, and sod farm in Malaysia (Uddin et al. 2010; Hakim et al. 2013). In September 2022, Buffalo grass with rust symptoms and signs were collected from the lawn located in Universiti Malaysia Sabah in the province of Sabah (6°01'55.6"N, 116°07'15.7"E). The incidence was 90%. Yellow uredinia were observed primarily on the abaxial surface of the leaves. As the disease progressed, leaves were covered with coalescing pustules. Microscopic examination of pustules revealed the presence of urediniospores. Urediniospores were ellipsoid to obovoid in shape, contents in yellow, 16.4-28.8 x 14.0-22.4 μm and echinulate, with a prominent tonsure on most of the spores. A fine brush was used to collect yellow urediniospores, and genomic DNA was extracted based on Khoo et al. (2022a). The primers Rust28SF/LR5 (Vilgalys and Hester 1990; Aime et al. 2018) and CO3_F1/CO3_R1 (Vialle et al. 2009) were used to amplify partial 28S ribosomal RNA (28S) and cytochrome c oxidase III (COX3) gene fragments following the protocols of Khoo et al. (2022b). The sequences were deposited in GenBank under accession numbers OQ186624- OQ186626 (985/985 bp) (28S) and OQ200381-OQ200383 (556/556 bp) (COX3). They were 100% similar to Angiopsora paspalicola 28S (MW049243) and COX3 (MW036496) sequences. Phylogenetic analysis using maximum likelihood based on the combined 28S and COX3 sequences indicated that the isolate formed a supported clade to A. paspalicola. Koch's postulates were performed with spray inoculations of urediniospores suspended in water (106 spores/ml) on leaves of three healthy Buffalo grass leaves, while water was sprayed on three additional Buffalo grass leaves which served as control. The inoculated Buffalo grass were placed in the greenhouse. Symptoms and signs similar to those of the field collection occurred after 12 days post inoculation. No symptoms occurred on controls. To our knowledge, this is the first report of A. paspalicola causing leaf rust on P. conjugatum in Malaysia. Our findings expand the geographic range of A. paspalicola in Malaysia. Albeit P. conjugatum is a host of the pathogen, but the host range of the pathogen especially in Poaceae economic crops need to be studied. Weed management could be an effective way to eliminate inoculum sources of A. paspalicola.

Estimation of Weed Biomass as Forage Production under Oil Palm Plantation

Palm oil plantations have the potency to provide forage as a source of energy for livestock. The objective of this research was to estimate the production and quality of weeds under palm plantation as ruminant feed. Identification was conducted to find out information about botanical composition, production and nutritional content to estimate potential forage. The study was conducted using a randomized block design with 2 blocks of 6- and 8-years old palm and 10 sample plots. The research parameters were botanical composition, weed dominance and diversity, and also forage production potency. The results showed that 19 species from 11 families were found and dominated by gramineae. The weed botanical composition and diversity level was affected by oil palm plantation age. On the 8 years old oil palm plantation, the number of weed species and diversity level were decreased, reaching 10 species and H’ 2.41 while on the 6 years old were 13 species and H’ 3.14. Based on the type of weed, Paspalum conjugatum P.J. Bergius is a weed that has the potential to be used as the highest forage as ruminant animal feed with an estimated production of 730.42 kg ha-1 of fresh biomash. The estimation of weed production ruminant forage was dominated by grass that had up to 1.87 ton ha-1 of fresh biomash.

Diversity and potential of herbaceous plants as mercury (Hg) hyperaccumulators in small-scale gold mining sites in Pancurendang, Banyumas, Indonesia

Abstract. Muryani E, Sajidan, Budiastuti MTS, Pranoto. 2023. Diversity and potential of herbaceous plants as mercury (Hg) hyperaccumulators in small-scale gold mining sites in Pancurendang, Banyumas, Indonesia. Biodiversitas 24: 3378-3386. Plants resistant to mercury can be used as an alternative to processing gold mining waste with the phytoremediation method. The study aimed to inventory herbaceous plant species in artisanal and small-scale gold mining (ASGM) sites in Pancurendang Village (Banyumas, Central Java, Indonesia), measure mercury concentrations in plants and root zones, and analyze the potential of herbaceous plants as mercury (Hg) hyperaccumulators. Herbaceous plants were cataloged by purposive sampling with multiple quadrats of 2m x 2m in 14 locations and then analyzed to obtain density, frequency, dominance, importance value, and diversity index. Biomass and Hg concentrations were measured from selected herbaceous plants and soil samples of the root zone. The Biological Accumulation Coefficient (BAC) was calculated to determine the plants' potential as Hg hyperaccumulators. Plant inventory identified 54 herbaceous plant species belonging to 26 families, with Paspalum conjugatum P.J.Bergius being the dominant species. In the root zones, Hg was found at 11-73 ppm and 7.6-85.36 ppm in 19 species. Ipomea aquatica Forssk. accumulated the highest concentration (85.36 ppm) and absorbed the greatest amount of Hg (5.25 mg). Based on their BACs, the nineteen species were categorized into moderate to high (hyper) accumulators, with Plectranthus sp. having the highest BAC of 4.54.

Occurrence of distinctive cells and effects of irradiance on vascular formation in leaves of shade-tolerant C4 grass Paspalum conjugatum.

The denser leaf vasculature of C4 plants than of C3 plants may suit rapid export of assimilates associated with their higher photosynthetic rate. However, some C4 grasses have partially reduced leaf vasculature with vascular bundle (VB)-free bundle-sheath cells called distinctive cells (DCs). The shade-tolerant C4 grass Paspalum conjugatum has such a reduced leaf vascular system with DCs. We examined whether irradiance during growth affects vascular formation in leaves of P. conjugatum grown under 100%, 30%, or 14% sunlight for 1 month alongside the C4 grass maize. Under all conditions, P. conjugatum leaves had partially reduced vasculature: DCs and incomplete small VBs without phloem occurred between VBs with a normal structure consisting of both xylem and phloem. Shaded plants had less phloem in the small VBs than the full-sunlit plants. In maize, however, all VBs always had both xylem and phloem under all light conditions. The net photosynthetic rate of both grasses was reduced under shade; that of P. conjugatum was always lower than that of maize under all light conditions, but was reduced less by shade than that of maize. The light compensation point was lower in P. conjugatum than in maize, indicating that P. conjugatum acclimatizes better to low light. The reduction of phloem in VBs of P. conjugatum may be an acclimatization to shade, because dense vasculature may be expensive for C4 plants growing in environments where the higher photosynthetic rate is not realized.

Synergistic test of atrazine 72% and mesotrion 8% herbicide against broadleaf weeds and grass weeds in corn (Zea mays L.) cultivation

Weed control employing single pesticide continually in the long-term causes weeds to become resistant. The usage of combined pesticides helps limit the occurrence of weed resistance. Herbicide formulations containing two or more active ingredients will exhibit interactions between constituents which could be synergistic, additive or antagonistic. The purpose of this study was to determine the effectiveness and synergism test of the mixture with the active ingredients atrazine 72%+mesotrion 8% against several types of weeds in sweet corn plantations. The experiment was carried out during 2022 at the Agricultural Training and Development Research Center, Padjadjaran University, Bandung, Indonesia. The treatment consisted of three types of herbicides with six dose levels, there was mixture of atrazine 72%+mesotrion 8%, herbicide atrazine 72% and herbicide mesotrion 8% with four replications. Target weeds included Ageratum conyzoides, Borreria alata, Synedrella nodiflora, Richardia brassiliensis, Eleusine indica, Digitaria ciliaris and Paspalum conjugatum. Data analysis used the percentage of weed damage to determine the effectiveness of each herbicide and linear regression analysis using the Multiplicative Survival Model (MSM) method to determine the LD50 of each herbicide. The results showed that the mixed herbicides atrazine 72%+mesotrion 8% suppressed the growth of the target weeds and had a treatment LD50 of 0.32 l/ha and an expected LD50 of 0.36 l/ha with a co-toxicity value of 1.125 ( greater than 1), so the mixed herbicides were synergistic.

Updating Biodiversity Status and Changes in the Permanent Monitoring Stations of San Roque Metals Incorporated Mining Areas, Tubay, Agusan del Norte, Philippines

Since 2015, biodiversity-related surveys have been conducted biennially in the San Roque Metals Incorporated (SRMI) mineral production areas in the Municipality of Tubay, Agusan del Norte, Philippines. The company established five permanent monitoring stations in the selected habitats to monitor biodiversity and species richness effectively. The present study assessed changes in the monitoring stations using a quadrat-transect method and compared the diversity and species richness of the previous sampling periods. The results of the floristic survey recorded 160 morpho-species of seed plants (angiosperms and gymnosperms), ferns, and their allies, with 52% comprising tree species. Over time, a significant increase in the number of species was observed at the monitoring stations; however, Shannon’s Diversity Index remained low (H'=2.3610; range 0.68-1.73) for all sites. The most dominant plant habits were trees, followed by ground-dwelling herbs, vines, and climbers. Paspalum conjugatum was the most dominant ground cover, occupying 22%, and other common grass species, such as Scleria scrobiculata, Dicranopteris linearis, and Imperata cylindrica, accounting for 19%, 14%, and 14%, respectively. Approximately 70% of the identified species were native, and 13.5% were endemic to the Philippines. Nine recorded species were listed on the Philippine Red List or the IUCN Red List of Threatened Species. Although it was found that the species richness of mining areas has slightly increased since the last floristic surveys, the study recommends considering the provisions for no-mine zones and genetic conservation areas for future mine restoration and rehabilitation activities.

SPECIES COMPOSITION, STRUCTURE, AND MANAGEMENT IN GAYO COFFEE-BASED AGROFORESTRY SYSTEM

Gayo coffee has many benefits in terms of the environment, economy, and socio-cultural aspects, especially for the Gayo tribe. Recently, Gayo coffee has been the main commodity for the plant cultivation of the Gayo tribe, including the Mude Nosar as local farmers. One of the ways to cultivate Gayo coffee is through an agroforestry system. However, limited reports on the tree species composition and its management in Gayo coffee-based agroforestry needs to be explored. This study aims i) to identify the tree species composition and structure, as well as 2) to analyze the management of Gayo coffee-based agroforestry system in Mude Nosar Village. The study method used plot establishment for vegetation analysis, and interviewed the Gayo coffee farmers. The results showed that the number of tree species at all growth stages was 26 species. The highest Important Value Index (IVI) at the understory and sapling level in order was rumput kerbau (Paspalum conjugatum) and Gayo coffee (Coffea arabica), while at the seedling, pole, and tree levels were dominated by lamtoro (Leucaena leucocephala). The local farmers often use lamtoro as a shade tree for Gayo coffee in agroforestry system. The species diversity index (H') showed low values at all growth levels, except for understory plants with moderate values. The horizontal structure of the tree stand showed an inverted J curve, meaning that the regeneration rate is normal. The vertical structure of the tree stand belongs to strata C and D. The local farmers have applied good Gayo coffee management practices through an agroforestry system including land and seed preparation, planting, maintenance, and harvesting techniques. Coffee seeds and seedlings are from natural regeneration. Plant maintenance techniques are carried out by weeding, pruning, organic fertilization, and controlling pests and diseases. The harvest coffee season is generally twice a year. The management of Gayo coffee using an agroforestry system impacts the ecological, economic, and social aspects.

Interdependence of effects between soil organic matter content and atrazine herbicide on weeds and sweet corn (Zea mays saccharata Sturt) yields

One of the efforts to increase sweet corn productivity is to suppress weed growth by using herbicides combined with organic matter. This study aimed at examining the effectiveness of the herbicide atrazine on weed growth, growth and yield of corn plants given different doses of organic C. The experimental design used was divided plot design with three main plots of organic fertilizer levels and six subplots of herbicides which were replicated thrice. The main plot factor was the C-organic content consisting of low (1.02%), medium (2.50%) and high (3.50%). The second factor was the dose of the herbicide atrazine, which consisted of six levels of treatment, namely, no herbicide, atrazine herbicide doses of 1, 1,4, 1,8, 2.2 and 2.6 kg/ha. The results showed that the combination of atrazine at a dose of 1.4-2.6 kg/ha with organic C content was effective in controlling Ageratum conyzoides, Panicum repens and Paspalum conjugatum weeds. Atrazine herbicide treatment at a dose of 2.2 kg/ha affected the length of the cob, the weight of the cob without the cob, the yield of plots and the yield per hectare.

Investigation of Asymptomatic Infection of Phellinus noxius in Herbaceous Plants.

The white-rot fungus Phellinus noxius is known to cause brown root rot disease (BRRD) in woody trees and shrubs. To understand the pathogenicity of P. noxius in herbaceous plants, we investigated 23 herbaceous weed and turfgrass species in 32 BRRD-infested sites in Taiwan and/or tested them by artificial inoculation. In the field survey, P. noxius was isolated from seven symptomless herbaceous species (i.e., Typhonium blumei, Paspalum conjugatum, Paspalum distichum, Oplismenus compositus, Bidens pilosa, Digitaria ciliaris, and Zoysia matrella). Potted plant inoculation assays suggested that P. noxius is able to infect Artemisia princeps, O. compositus, and Z. matrella but not Axonopus compressus, Eremochloa ophiuroides, Ophiopogon japonicus, or Cynodon dactylon. A. princeps plants wilted within 2 weeks postinoculation, but inoculated O. compositus and Z. matrella were asymptomatic, and P. noxius could be isolated from only inoculated sites. The colonization of P. noxius in the cortex and vascular cylinder of roots was visualized by paraffin sectioning and trypan blue staining of juvenile seedlings grown on water agar. To evaluate the effect of replantation for the remediation of BRRD-infested sites, P. noxius-inoculated wood strips were buried in soil with or without vegetation. After 4 weeks, P. noxius could be detected only in the bare soil group. For the control of BRRD, the herbaceous hosts should be removed around the diseased trees/stumps and non-host turfgrasses (e.g., A. compressus, E. ophiuroides, O. japonicus, or C. dactylon) planted to accelerate the degradation of P. noxius.

Diversity and Prediction of Corn Product Loss Due Weed Competition to Two Types of Dry Land Agroecosystem

The aim of the study was to determine which weed species had a significant effect on the reduction of maize yields, so that it could be determined which species should be controlled and which should not be controlled. The research was carried out using a descriptive method on dry land in Mumbul Sari Village, Bayan, North Lombok. Collecting data on population and growth of weeds and plants, using sample plots measuring 1 m2 placed at 10 points by random sampling. Parameters observed were weed species population, corn crop population plot-1, dry biomass weight of plot-1 weed, dry biomass weight of plot-1 corn, and dry seed weight of corn plot-1. Quantitative data analysis by calculating the value, relative density (RN), relative frequency (RF) and relative dominance (RD) to calculate the significant value index (SVI), and Summe Diminance Ratio (SDR). There were 2 species of puzzle weed, 10 species of Poaceae weed and 13 species of broadleaf weed. One species of puzzle weed, namely Cyperus rotondus and 3 species of Poaceae Digitaria longiflora, Paspalum conjugatum and Panicum repens, and 2 species of broadleaf weed, Amaranthus spp., and Synedrella nodiliflora, were very dominant and continued to exist during plant growth with respective SDR values each species 10.43%; 15.37%; 10.20%; 9.67 %; 10.00% and 5.80%. The competitiveness and relative weighted dominance of the 6 weed species were higher than other weed species, so that the six weed species were able to eliminate the average maize yield since the plants were 30 – 90 as much as 17.90%; 16.78%; 12.35%;10.88%; 9.18% and 3.40%

Composition, structure, and level of weed diversity in oil palm plantation in Pagar Merbau Village, Tanjung Morawa, Indonesia

Weed vegetation growth affects the growth and production of oil palm plants. To control weeds in plantation land, especially by using herbicides or bioherbicides, weed vegetation analysis is needed. This research was conducted to determine the composition, structure, and level of diversity of weeds in oil palm plantations owned by the community of Pagar Merbau village, Tanjung Morawa District. The method used is a descriptive method with sampling technique done by porposive sampling. The results of the analysis showed that weeds found were 7 families, 10 species, and 3153 individuals. Weed species found were: Clidemia hirta, Borreria alata, Mimosa invisa, Setaria barbata, Ageratum conyzoides, Paspalum conjugatum, Ottochloa nodosa, Cyclosorus aridus, Calopogonium mucudoines, Ophioglossum reticulatum. Ottochloa nodosa is a type of weed that has the highest importance value index 66.52% (1323 individuals) and Setaria barbata is a type of weed that has the lowest important value index of 1.00% (4 individuals). Weed diversity index in this oil palm plantation is in the moderate category (H '= 1.3741). The weed control system to be carried out in this oil palm plantation must consider the dosage and types of herbicides and bioherbicides used so that it does not have the potential to reduce the level of diversity of weeds of grass or broadleaf weeds.

CHARACTERIZATION AND MYCOTOXIN ANALYSIS OF Fusarium spp. FROM HIGHLAND AREAS IN MALAYSIA

Fusarium isolates from highland areas in Malaysia were mostly recovered from two species of grasses, Elyhordeum montanense and Paspalum conjugatum. The isolates were grouped into four morphological groups. Based on TEF-1α sequences, morphotype 1 isolates were molecularly identified as F. graminearum species complex, morphotype 2 as F. venenatum, morphotype 3 as F. avenaceum and morphotype 4 as F. kyushuense. Restriction analysis of the Intergenic Spacer region showed high levels of genetic diversity of isolates in F. graminearum species complex and F. venenatum. For mycotoxin analysis, only F. avenaceum and F. kyushuense produced beauvericin and moniliformin (0.869 & 0.321 µg/kg, respectively). Zearalenone was produced by 32 isolates of F. graminearum species complex (0.002 – 0.437 µg/kg), two isolates of F. venenatum (0.006 - 0.014 µg/kg) and F. kyushuense (0.006 µg/kg). Only F. avenaceum isolate produced fumonisin B1 (0.001 µg/kg). The present study indicates the occurrence of Fusarium species commonly reported in highland areas in Malaysia where the weather is cooler and the temperature is lower than in the lowland areas. To our knowledge, this is the first report on the occurrence of phylogenetic species within F. graminearum species complex, F. venenatum, F. avenaceum and F. kyushuense in Malaysia.

Effect of Chitosan Molecules on Paraquat Herbicidal Efficacy under Simulated Rainfall Conditions

Unexpected rainfall before herbicide absorption by plants can wash away herbicides from plant tissue surfaces, which may reduce the herbicidal efficacy and increase the adverse effects on nontarget organisms and the environment, including water networks. The objective of this study was the evaluation of the effect of chitosan on paraquat efficacy under simulated rainfall conditions. Simulated rainfall within 3 h after paraquat application decreased its herbicidal efficacy. A mixture of paraquat (280 g a.i./ha) and chitosan (0.05% w/v) significantly increased the herbicidal efficacy against Ageratum conyzoides L. (21% increase), Borreria alata Aubl. (15%) and Paspalum conjugatum Bergius (8%) under the rainfall conditions. The chemical structure of chitosan may contribute to the penetration of paraquat into plant tissues. However, a mixture of paraquat and chitosan did not affect the herbicidal efficacy against Imperata cylindrica (L.) Beauv. The morphological characteristics of I. cylindrica may interfere with the enhancement effect of chitosan. Chitosan is a degradable, nontoxic and easily available and low-cost material made from crustacean shells. These results suggest that chitosan may increase paraquat efficacy against some noxious weed species under rainfall conditions, which may reduce the risk of paraquat contamination into the environment. Therefore, the application of herbicides with chitosan may provide the economic and environmental benefits. Chitosan may enhance the efficacy of other herbicides under unexpected rainfall conditions; however, this possibility requires further investigation.

Association among Lepironia articulata Cyperaceae, peat soil and people in Wanggate, Mappi, Papua

Wanggate is a small village that is surrounded by water like a small island in the wetland area. A creek connecting to a main river is a mean of transportation to reach Mappi or another nearby village. Next to the river, population of grass were living and periodically waterlogged by the river. L. articulate, a species under Cyperaceae family, grows abundantly in small lake or pool that has connection to the river. Dark green color is a sign of L. articulata presence. The grass could reach up to 2 m tall and lives above water. Relationship among people, plants with peat soil has been present since a long time. The research was undertaken to understand more about the association. The nature of this study was descriptive with interviews to obtain ethnobotanical data. Fifty plot-wise sampling technique was used to collect data. The result shows that L. articulata shrub was the habitat of freshwater fishes like nila (Oreochormis niloticus), Channa sp. and shrimps. People has been dependent to fisheries from the lake and grasses for living. They make bags, arm straps, traditional hats, umbrellas, mats, kitchen utensils like baskets and plates, clothes and roofs from L. articulata. Peat soil was found in 31 plots and 28 of those plots were covered by L. articulata. Association index between of L. articulata and peat soil was 0.875 and dominance index of the plant was 0.868. The other plants, Melaleuca cajuputi, were found in 3 plots. The research discovered Paspalum conjugatum, grass-type vegetation, which associated with mineral soil like sago palm (Metroxylon sago).

Forage Potential of Plant Species Found in Various Ecosystems in Musi Banyuasin Regency, South Sumatera, Indonesia

Forage is an important component in sustainable smallholder livestock. The purpose of the study was to identify the diversity of natural plant species in various ecosystems, as well as their potential as forage. Based on our surveys of palm oil plantation, rubber plantation, and home gardens using the quadrant method, we identified approximately 50 species comprising the natural vegetation of our study area. Out of 50, we identified 39 broad-leaved species, 9 grasses (Poaceae) species, and 2 sedges (Cyperaceae) species. The palm oil plantation had 29 species dominated by Ottochloa nodosa (11.92%) and Asystasia gangetica (11.40%); 25 species were found in the rubber plantation dominated by Cynodon dactylon (28.42%) and Panicum repens (9.20%), and home gardens contained 30 species dominated by Eleusine indica (13.39%) and Ageratum conyzoides (9.60%). Among the 29 species found in the palm oil plantation, 13 were observed to have low palatability scores, and 16 species have high palatability scores. Based on their high palatability scores, the following species can be utilized as forage for Balinese cattle: Cyrtococcum acrescens, Eleusine indica, Centrosema pubescens, Paspalum conjugatum, and Sida rhombifolia.

Rice Waste Hydrolyzation at Subcritical Temperature to Produce Bioherbicide to Control Terrestrial Weeds

Thermal anaerobic hydrolyzation process on rice husk with higher lignin content produced organic complexes constituents including phenolic groups. Phenolic groups expose herbicide effects on growing vegetations, where the process in nature mainly require anaerobic condition. The degradation rate in nature is very slow with very low concentration availability. Thermal hydrolyzation is an appropriate choice to produce phenolics herbicide for sustainable pesticide management and application. This study aimed to identify the potency of rice husk extract by thermal hydrolyzation process as an organic herbicide to control terrestrial weeds. The hydrolyzation was processed in 60-90 bars and 280±20 °C for 30±10 minutes. The existence of the phenolic groups in the hydrolysate was considered for generic active ingredients to control weed in the terrestrial ecosystem. Its damage impact was tested on Borreria alata, Eleusine indica, Cyperus kyllingia, Paspalum conjugatum, Asystasia intrusa, and Axonopus compressus. The assay covered the growth at pre-emergence, early post-emergence, and post-emergence growing stages. The rice waste hydrolysate was capable to suppress the growth of the weed growth especially at the pre-emergence stage at 30-64%, and at early post-emergence stages at the suppressing rate of 77-100%. However, the suppressing affectivity is lower at the post-emergence stage which only 17-25%.

Enteric methane emissions by young Brahman bulls grazing tropical pastures at different rainfall seasons in the Peruvian jungle.

The aim of this research was to measure enteric methane (CH4) emissions by young Brahman bulls grazing tropical pastures at different rainfall seasons in the Peruvian jungle. Fourteen 1.5-year-old, young bulls (280kg ± 18kg BW) were grazed on tropical grasses and legumes dominated by German grass [Echinochloa polystachya (Kunth) Hitch.] and minor proportion of Torourco grass [Paspalum conjugatum (P.J. Bergius) Roxb] and Leguminous Calopo (Calopogonium mucunoides Desv.) and Kudzú [Pueraria phaseoloides (Roxb.) Benth]. Enteric CH4 emission was measured by the sulfur hexafluoride (SF6) tracer-gas technique. Organic matter intake (OMI) was determined from organic matter digestibility (OMD) using a fecal protein crude index and fecal output estimated by the dosage of external markers. There was a difference in OMD between seasons (68 and 66% for the dry and rainy seasons, respectively; P < 0.0001). The OMI (6.7 and 7.4kg/day) and CH4 (178.7 and 298g/day) were higher (P < 0.05) in the dry season than in the rainy season, respectively. The yield of CH4 was lower (P < 0.0001) during rainy season (7.1%) than at the dry season (10.6%). The CH4 emission (g/day) was correlated with OMD (%) (r = 0.74, P < 0.0001). Enteric CH4 emissions of young bulls grazing mixtures of tropical pastures were significantly lower in animals grazing on the rainy-season, expressed either through unit of absolute emission, intake or as percentage of the GEI. Likewise, OMD of consumed pasture was the most important factor determining CH4 emission.

KEANEKARAGAMAN DAN KEGUNAAN TUMBUHAN BAWAH PADA BEBERAPA TEGAKAN DI ARBORETUM BALAI PENELITIAN DAN PENGEMBANGAN TEKNOLOGI SERAT TANAMAN HUTAN (BP2TSTH) KUOK

Underground plants have an important role in soil and air conservation efforts, namely as a source of organic matter, preventing erosion, a source of germplasm and increasing air infiltration into the soil. This study aims to identify the types, diversity and use of understorey under stands of meranti, gaharu and mixed stands in the arboretum of the Kuok Forest Plant Fiber Technology Research and Development Institute (BP2TSTH). The data collection method used systematic sampling with a random start, with a sampling intensity of 5%. The number of plots observed for meranti, gaharu and mixed stands were 50, 25 and 25, respectively, with a plot size of 2 x 2 (m). In the stands were found 17 families of undergrowth consisting of 23 species and 10,338 individuals. In the agarwood stands there are 10 families of undergrowth consisting of 13 species and 9,696 individuals. In the agarwood stands there are 11 families with a diversity of 13 species and 10,328 individuals. Diversity Index and Evenness Index in meranti, gaharu and mixed stands respectively; 1.25 and 0.4; 0.72 and 0.28; 0.72 and 0.28. Paspalum conjugatum is a understorey species with the highest Importance Value Index (IVI) in the three stands.