Weed Samples Research Articles

An Appraisal of the Potential of Sequestering Carbon through Pomegranate Orchards in India

Pomegranate is an important arid and semi-arid fruit crop of Indian origin. Land use change from agriculture to pomegranate orchards not only enhances farmers’ income but also helps in sequestering carbon and provides additional ecosystem services. Assessing carbon stocks and stock changes in fruit orchards is crucial under the United Nations Framework Convention on Climate Change and the Kyoto Protocol. In this context, we conducted a study to estimate carbon stocks in pomegranate orchards in India. We developed an exclusive allometric equation to estimate pomegranate tree biomass and collected extensive samples of trees, litter, weeds, and soil. We grouped pomegranate-growing areas by similarity in variety, soil, and climate, and then calculated the carbon held in these pools. Finally, we computed the carbon sequestered by pomegranates per hectare, providing valuable insights for climate change mitigation efforts. The national-level carbon storage in pomegranate orchards was then computed by multiplying the area occupied by pomegranate in these regions by the amount of carbon sequestered in one ha of land. Nearly 42.49 mt of carbon is sequestered in the pomegranate orchards of the country with 18.42 mt (43.36% of the total CS) stored in tree biomass and 24.1 mt (56.71% of the total CS) stored in soil. This study underscores the important role of pomegranate orchards in India, not only as a lucrative agro-economic venture for farmers but also as a significant contributor to carbon sequestration and overall ecosystem services. Such insights are essential for guiding sustainable land use practices and aligning agricultural efforts with global climate change mitigation strategies.

A new strategy for weed detection in maize fields

Timely determination of weed distributions in fields is crucial for the precise spraying of herbicides. This facilitates weed control while saving costs and protecting the environment. Existing weed detection strategies often rely on the utilization of numerous weed samples to train detection models directly, which presents challenges in situations involving limited weed samples. To address this issue, a novel weed detection strategy was proposed in this study to identify weeds accurately in fields with varying coverage levels. For this purpose, red–green–blue (RGB) images of maize fields with different weed coverage levels were captured via a vertical take-off and landing fixed-wing unmanned aerial vehicle (UAV). The UAV images were first mosaicked, and a new weed detection strategy was developed and assessed. In this process, the MeanShift segmentation method, coupled with the local variance (LV) segmentation evaluation function and the Otsu automatic classification method, was initially employed to extract vegetation areas. The you-only-look-once (YOLO) v5n model was subsequently improved and used to detect maize plants. Finally, weed mapping was achieved by removing the identified maize plants from the vegetation through overlay analysis. The evaluation of the proposed method via an external dataset yielded favorable weed detection results, with an R2 value of 0.96 and a root mean square error (RMSE) value of 3.08 % under the different weed coverage levels. Specifically, in addition to adjusting the activation function and the nonmaximum suppression method, the impacts of integrating various attention modules at different positions on the performance of the YOLO v5n model for maize plant detection were analyzed. Improving the YOLO v5n model by incorporating the efficient channel attention (ECA) module into the backbone of the original model and utilizing the Hardswish activation function is recommended. Overall, this study offers support for precise weed control.

A sensitive method for the determination of per- and polyfluoroalkyl substances in food and food contact material using high-performance liquid chromatography coupled with tandem mass spectrometry

Dietary intake is the major pathway of human exposure to per- and polyfluoroalkyl substances (PFAS). Due to their generally very low concentrations in food, especially for foods of plant origin, and their toxicological relevance, demand is growing for improved selective and sensitive analytical methods for the determination of PFAS in the lower ng/kg range. The relevance is pointed out due to the fact that the European Commission has published limits of quantification (LOQs) in the lower ng/kg range for different food matrices in Recommendation (EU) 2022/1431 on the monitoring of perfluoroalkyl substances in food. For example, LOQs of 2 ng/kg for perfluorooctanesulfonic acid (PFOS), 1 ng/kg for perfluorooctanoic acid (PFOA), 1 ng/kg for perfluorononanoic acid (PFNA) and 4 ng/kg for perfluorohexanesulfonic acid (PFHxS) in fruit, vegetables and baby foods are required. A new, very sensitive method is presented here for the determination of 22 PFAS in food and food contact materials. The method is based on liquid-solid extraction and automated clean-up using two solid phase extraction techniques. The analytes are separated and detected by HPLC-MS/MS. A limit of detection (LOD) of 0.33 ng/kg and an LOQ of 1.0 ng/kg are attained for plant foods such as fruits and vegetables as well as for milk and baby food. For foods of animal origin such as egg, meat, fish and paper-based food contact materials an LOD of 1.6 ng/kg as well as an LOQ of 5.0 ng/kg are attained. PFOS and PFOA were the most abundant compounds in the food samples with concentration as high as 1,051 ng/kg of PFOA in sea weed samples and 772 ng/kg of PFOS in eggs samples. In food contact material samples, higher levels were found with a maximum of 310,000 ng/kg PFHxA. In sum the presented method firstly allows determination of PFAS in a wide variety of foodstuffs and paper-based food contact materials at EU-required concentration ranges.

Dynamics of weeds and main pests in different rice planting systems supplemented with biodecomposer

Biodecomposers are used as an alternative in pest and weed management by utilizing antagonistic microbes. This study aimed to identify the optimal treatment for suppressing weed growth and controlling the main rice pests, promoting environmentally friendly agricultural practices. Observations were made on three phases of rice growth on land that used biodecomposer and did not use biodecomposer. Weed sampling used a quadrant, which represents each treatment. All weeds were analyzed for density and summed dominance ratio. Pests were observed from the sweep net method. Pests were analyzed with the Shannon-Wiener diversity index (H’). Ten species of weeds are found; the most common and dominant was Cyperus difformis, while the least were Ipomoea aquatica and Ludwigia octovalvis. There were seven pest species; the most common was Nephothettix virescens, while the least was Valanga nigricornis. Using bio-decomposers combined with a two-row planting system was effective in suppressing the development of weeds and pests with a decreasing trend as the rice growing phase increases. Biodecomposers are environmentally friendly even though the process is slow, and have the potential to reduce weeds and pests.Keywords: biodecomposers, Jarwo 2:1, Tegel, trichoderma

Inventarisasi dan Studi Dispersal Gulma Asing Invasif di Kebun Biologi UIN Sunan Gunung Djati Bandung

Invasive alien weeds are plant pests because they can interfere with the growth and productivity of surrounding plants. Studies of invasive alien weeds, inventory of species, and their dispersal are important not only in conservation environments but also in study areas in educational institutions such as universities. This research was conducted with the aim of being an initial study to determine the types and distribution vectors of invasive alien weeds in the study area of the biology garden of UIN Sunan Gunung Djati Bandung which have the potential to disrupt the surrounding ecosystem. Weed sampling was carried out by purposive sampling exploration method in the biology garden area of the Faculty of Science and Technology UIN Sunan Gunung Djati Bandung. Based on the inventory results, a total of 16 species and 8 families of invasive alien weeds were obtained with the most families coming from the Asteraceae family. The invasive alien weed seed dispersal vectors include wind, water, and animals. Most invasive alien weed species found in the sampling sites have wind and animal dispersal vector types (31.25%). Seed dispersal by animals and wind has an effective dispersal rate because the range of distribution is quite wide. In addition, the characteristics of seeds, the ability to adapt and develop in new environments in plants such as species of the Asteraceae family can cause their invasion to take place quickly and massively.

First report of cucurbit yellow stunting disorder virus infecting cucurbit crops in Jamaica.

The increasing prevalence of whitefly-transmitted viruses affecting cucurbit crops has emerged as a significant concern for global cucurbit production. Two of the most widely prevalent threats in the Americas are cucurbit yellow stunting disorder virus (CYSDV) and cucurbit chlorotic yellows virus (CCYV) (Crinivirus, Closteroviridae). These viruses induce similar foliar symptoms on cucurbit crops (Mondal et al., 2023) leading to loss of photosynthetic capability and decreased yields. Cantaloupe (Cucumis melo), watermelon (Citrullus lanatus), and cucumber (Cucumis sativus) are major cucurbit crops in St. Elizabeth, Jamaica, which is the principal fruit and vegetable producing region of the country. In August 2018, foliar symptoms were observed on cantaloupe, watermelon, and cucumber plants in several commercial farms in St. Elizabeth. These symptoms, mainly on the older leaves, consisted of severe yellowing or interveinal mottle and they appeared more pronounced on cantaloupe and cucumber plants compared to watermelon. Growers noticed the production of smaller than normal fruit. Disease incidence ranged from 10 to 100% and whiteflies (Bemisia tabaci Gennadius) were observed in the fields. To identify virus(es) associated with the disease, six plants (cantaloupe [n = 3], cucumber [n = 1] and watermelon [n = 2) exhibiting symptoms were sampled from four fields for preliminary screening. Total RNA was extracted from leaf tissues as described in Tamang et al. (2021) and samples tested by a multiplex reverse transcription RT-PCR method that targeted the RNA-dependent RNA polymerase (RdRp) of the whitefly transmitted viruses, CYSDV, CCYV, squash vein yellowing virus (SqVYV), and the aphid- transmitted cucurbit aphid-borne yellows virus (CABYV) (Mondal et al. 2023). RT-PCR amplified the expected 494-bp fragment of the CYSDV RdRp gene (Mondal et al., 2023) from two symptomatic plants; one cantaloupe, one cucumber, as well as from CYSDV-infected control plants but not from healthy controls. Further testing was conducted during the June-August 2020 growing season after similar symptoms were observed on additional farms in St. Elizabeth and two regions, Manchester and Clarendon, located to the east of St. Elizabeth. Twenty-one cucurbit leaf samples (11 cantaloupe, seven watermelon and two cucumber from St. Elizabeth and one cantaloupe from Clarendon) exhibiting foliar yellowing progressing from the crown outward, and mottling were collected. Whiteflies (5) from these fields in St. Elizabeth and 20 asymptomatic weed samples were also collected and sent to the USDA-ARS laboratory at Salinas, CA. Total RNA from leaf samples was extracted as described above and tested for CYSDV, CCYV, and CABYV. Total leaf DNA was also extracted (Mondal et al. 2016) and assayed with PCR (Gilbertson 2001) to detect the presence of the whitefly-transmitted cucurbit leaf crumple virus (CuLCrV), a begomovirus, commonly found in the southeastern United States (Gadhave et al., 2018; Keinath et al., 2018). Nineteen of the 21 cucurbit samples tested positive for the presence of CYSDV by RT-PCR (Mondal et al. 2023). Of the 19 CYSDV-positive samples, 13 cantaloupe, one cucumber, and five watermelon samples were singly infected with CYSDV, and one cantaloupe sample was infected with both CYSDV and CABYV. Amplicons of the Jamaica isolate from cantaloupe were sequenced (OR399555) and a 494 nt section of the RdRp gene was found to share 100% sequence identity to the Arizona 1 isolate (EF547827.1). The presence of CYSDV, was further confirmed using a second set of primers that amplified a 394-nt portion of the CYSDV coat protein gene (Polston et al., 2008). Among the weed samples, CABYV was detected in one sample from a Leonotis nepetifolia plant (Lamiaceae) and two Cleome sp. (Capparaceae) collected from St. Elizabeth. None of the crop and weed samples tested positive for CCYV or CuLCrV. DNA from whiteflies was extracted and assayed with PCR using species specific primers (Chen et al. 2016). All whiteflies were identified as B. tabaci cryptic species MEAM1, which is widely known an efficient vector of CYSDV (Berdiales, et al. 1999). This is the first report of CYSDV in Jamaica and its first known occurrence in these hosts within the country. Further monitoring of cucurbit crops and the whitefly vector is warranted to better understand the epidemiology.

LAJU TUMBUH GULMA PADA BERBAGAI PUPUK ORGANIK DAN UKURAN BENIH DI PERTANAMAN KENTANG (Solanum tuberosum L.) DATARAN MEDIUM

Weeds are one of the causes of the decline in potato production in the central plains. This research aimed to assess the diversity of weeds that appear on granola-variety potato plants (Solanum tuberosum L.) This research uses a quantitative approach by arranging frames measuring 50x50 cm in five locations spread diagonally. Weed samples were taken at 20 and 40 days after planting, and then the weed vegetation was analyzed using the index formula and weed dominance. The research found nine types of weeds, namely: Cyperus rotundus, Ageratum conyzoides L., Common purslane, Eleusine indica L. Gaertn, Commelia benghalensis, Panicum repens L., Amaranthus spinosus L., Gynura procumbens, and Bidens pilosa L. Analysis result the variety shows the level of weed diversity at 20 days after planting in the P0 treatment wich gives the best result with the lowest average value. Meanwhile, in weed diversity parameters at 60 days after planting, the highest average value was achieved by treatment P1, while the lowest average value was seen in treatment P3.

Potency of Some Savanna Herbaceous Weeds in the Production of Bioethanol Using Zymomonas mobilis and Saccharomyces cerevisiae

The uncertainty of the fossil fuel and global climate changes has invariably led to renewable energy demand. Thus, necessitating increasing biotechnological research efforts. Accordingly, the current work was designed to investigate the potency of some savanna herbaceous weeds in the production of bioethanol using Zymomonas mobilis and Saccharomyces cerevisiae. The biodiversity study and the proximate analysis of weed samples growing on Bayero University Kano old Campus, Nigeria were carried out. The substrates were pretreated with 2% of 0.233M sulfuric acid solution and hydrolysed using Aspergillus niger. The reducing sugars were estimated using the dinitrosalicylic acid method. Fermentation was carried out using local strains of Zymomonas mobilis and Saccharomyces cerevisiae isolated from fermented Zobo drink and palm wine under anaerobic conditions. The absorbance of the produced bioethanol was measured and compared with the known standard ethanol curve using Techme I Uv-vis spectrophotometry at 600nm. The dominant weeds include; Cynodon dactylon (30%), Heteropogon contortus (20%) and panicum virgatum (13.45%). The carbohydrate contents as hemicellulose ranged from (35.44 - 27.68%), cellulose (39.80 - 29.20%) and lignin contents (4.32 - 2.14%). The reducing sugar ranged from (24.67±0.01 - 94.79±0.01 mg/g) in all the substrates used. Maximum bioethanol yield was obtained with Cynodon dactylon (48.09±0.07ml/g) in fermentation with a cocktail of the microorganisms whereas, the minimum yield was observed with Heteropogon contortus (15.08±0.01 mL/g). Zymomonas mobilis had the maximum bioethanol yield (29.20±0.01ml/g) than Saccharomyces cerevisiae with (20.10±0.01 mL/g) bioethanol (p>0.05). The findings reveal the lignocellulosic weeds used in this study are good substrates which can be exploited in bioethanol production.

TRACES OF GLYPHOSATE IN CORN (Zea mays L.) AND AVOCADO (Persea americana Mill.) WEEDS SUPPORTED BY VANT AND RAMAN SPECTROSCOPY

Since the 1990s, radiometric and biophotonic sensor applications have provided reliable alternatives and rapid non-invasive diagnostics for the detection and delimitation of pests and diseases, as well as pesticide traces. Active sensors have been shown to be more accurate in detecting the heterogeneity of environmental factors based on thermal and infrared characteristics, chlorophyll fluorescence, and plant reflectance. Unmanned Aerial Vehicles (UAVs) equipped with infrared cameras locate and delimit weed abundance and diversity using Normalized Difference Vegetation Index (NDVI) algorithms, which highlight heterogeneous chlorophyll activity and herbicide-limited photosynthesis in crops. The resulting map serves as the foundation for collecting plant samples. In this study, the technology of these sensors was applied to determine glyphosate traces using Raman spectroscopy, which allowed a quick, low-cost, simple, and practical diagnosis with immediate results. These are essential characteristics for surveillance and monitoring activities, as well as the basis for a geo-referenced inventory of pesticides in production units. Of the 44 weed samples collected, eight were positive for glyphosate traces: two in corn and six in avocado. Weeds are identified as positive to glyphosate traces in Raman spectroscopy in the carotenoid and phenylpropanoid reduction ranges (1186 and 1213 cm-1) as a result of a decrease in the immune response. The vibrations presented by the amines in glyphosate and the C-OH of the carboxyl group are detected in the range of 1565 and 1567 cm-1.

Exploring the interplay between Arbuscular Mycorrhizal Fungi and weed dynamics in agricultural ecosystems.

Weeds are responsible for major crop losses worldwide but can provide beneficial agroecosystem services. The present study aimed to study the association of arbuscular mycorrhizal fungi in common weeds found in agro-ecosystem. Around 19 weeds were collected from various locations of eastern dry zone of Karnataka. The mycorrhizal association was determined by root staining technique. Of the 18 weed samples, AM fungal association was found in 17 weed species and the percent root colonization ranged from 10-68 %. Highest root colonization was found in weeds belongs Graminaceae family. The result of the study concludes that, AM fungi colonizes the weeds and they may act as host during the off seasons.

DIVERSITY OF WEED SPECIES IN COCOA PLANTATIONS IN BANYUWANGI, EAST JAVA, INDONESIA

Cocoa (Theobroma cacao L.) is one of the important plantation commodities in Indonesia. However, one of the factors that can affect productivity is weeds because weeds compete with cocoa in getting water, sunlight, nutrients, air, and space to grow. One of the largest cocoa plantation areas in East Java is the Banyuwangi district. Information about the types of cocoa weeds in Banyuwangi is unknown even though weeds in one area are different from another. Weed can reduce the production of cocoa. So, This study is important for determining appropriate control methods. This study aimed to determine the type, diversity, and abundance of weeds. The research method used in this study was a survey with a square-plot size. All weed samples were identified. The results showed that there were twelve types of broadleaf weeds, three types of grass weeds, one type of sedge, and one type of fern. The highest importance value index (IVI) was found in Ottochloa nodosa at 40.91%. The diversity of weeds was in a medium category. Weed diversity in cocoa plantations in Banyuwangi was different from other areas in Indonesia. The results of this research contribute to providing information on the diversity of weeds that can be used in determining weed control strategies in cocoa plantations.

Weed Community Structure in Patia Village Rice Fields Patia Sub-District, Pandeglang Regency

Rice is a very important type of food crop because it is a staple food source. Crop losses at the farmer level due to competition with weeds reach 10-1.5%. This study aims to determine the structure of rice weed communities in rice fields in Patia Village, Patia District, and Pandeglang Regency. The research method uses an observation method with the sampling technique used as a random method. The plot used was 2 m x 2 m. Weed sampling was carried out by recording the types of weed types and counting the number of individuals of each species. Measurements of environmental factors such as temperature, humidity, pH, and light intensity were measured. The data parameters measured include the Shannon-Wiener diversity index (H'), evenness index (J'), dominance index (D), wealth index (S), and abundance of rice weed species. The results of the study were that the types of rice weeds found in the rice fields of Patia Village, District, and Patia, Pandeglang Regency, namely Ludwigia octovalvis (Jacq) Raven, Commanded cylindricaL. Beauv, Spigelia anthelmia, Ageratum conyzoides, Spihemoclea zeylanica, Altemanthera sessillis, Eclipta prostate, Cypress deformed L., Digitaria sp. and Mimosa chaste L. The structure of the weed community in the rice fields of Patia Village, Patia District, Pandeglang Regency is the Shannon-Wiener Diversity Index (H') of 1.94; Evenness Index (J') of 0.884; Dominance Index (D) of 0.15.

Evaluation of the Weeds around Capsicum annuum (CA) Cultivation Fields as Potential Habitats of CA-Infecting Viruses.

Capsicum annuum (CA) is grown outdoors across fields in Jeollabuk-do, South Korea. The weeds surrounding these fields were investigated regarding the infection of 11 viruses infecting CA during the year 2014-2018. In the reverse transcription polymerase chain reaction diagnosis, 546 out of 821 CA samples (66.5%) were infected by nine viruses, and 190 out of 918 weed samples (20.7%) were infected by eight viruses. Correlation analysis of the mutual influence of the viruses infecting CA and weeds during these 5 years showed that five viruses had significant positive correlations with the infection in both CA and weeds. Over the study period, the weeds infected by cucumber mosaic virus (CMV) in the previous year were positively correlated with the incidence of CMV infection in CA in the current year, although the correlation was lower for tomato spotted wilt virus (TSWV) compared to CMV. The CMV infection percent was 14.0% in summer annuals, 11.4% in perennials, and 7.8% in winter annuals. However, considering the overwintering period without CA, the infection percent was 5.2% higher in winter annuals and perennials than that in summer annuals, indicating that winter annual and perennial weeds served as the main habitats for insect vectors. The TSWV infection percent in weeds was 10.4% in summer annuals, 6.4% in winter annuals, and 6.2% in perennials. The weeds surrounding CA fields, acting as the intermediate hosts, were found to be the potent sources of infection, influencing the spread and diversity of CA-infecting viruses. The results of this study can contribute to prevent viral infection in agricultural fields.

Weed Availability as A Ruminant Forage Source on Coffee Farmers' Land in Kandang Village, Indonesia

The study aimed to calculate the availability of weeds as a source of forage for livestock in coffee farmers' land, Kandang Village, Seberang Musi District, Kepahiang Regency, Indonesia. The study employed the survey approach, with observations in the field and a questionnaire distributed to 81 families as the research sample. The research sample comprises 42 hectares of land. Weed samples were collected on a 1 m x 1 m square plot. The 17 squared plots were set randomly on the research site to identify weed species, production, nutrient content, and land-holding capacity of ruminants. The results of the study showed that there were 14 types of weeds in the field, namely Setaria plicata, Asystasia gangetica, Imperata cylindrica, Mikania micrantha, Crassocephalum crepidioides, Arachis pintoi, Kyllinga monocephala Rottb., Digitaria adscenden, Peperomia pellucida, Ageratum conyzoides, Chromolaena odorata, Borreria alata, Clidemia hirta, and Mimosa pudica. Weed production was estimated at 26.4 tons/ha/year. Five types of weeds contain good nutrition to be used as feed for ruminants. The weeds were S. plicata with water content (11.87), ash (7.11), fat (0.50), protein (11.15), crude fiber (26.43); B. alata, water content (9.52), ash (8.92), fat (1.66), protein (13.14), crude fiber (19.67); C. crepidioides, water content (15.80), ash (21.03), fat (1.47), protein (19.46), crude fiber (9.37); M. micrantha, water content (11.40), ash (6.53), fat (2.08), protein (12.93), crude fiber (17.35) and A. gangetica, water content (11.405), ash (9,135), fat (1,635), protein (13,645), crude fiber (23,91). The land-holding capacity of ruminants reaches two livestock units per year.

Komposisi, Dominansi, dan Pemanfaatan Gulma Agroforestri Jambu Mete (Anacardium occidentale L.) di Desa Gemawang Kecamatan Ngadirojo Kabupaten Wonogiri

Gemawang Village, Ngadirojo District, Wonogiri Regency, Central Java Province is home to one of the cashew (Anacardium occidentale L.)-based agroforestry operations. In agroforestry management, plants are one of the factors that can impede cashew production growth. To determine the success of weed control, it is necessary to first acquire an understanding of weed species. There were 2 stations in this study, namely cashew-based agroforestry ecosystem stations and teak monoculture ecosystems.This study assessed the composition, dominance, and prospective use of weed vegetation in cashew-based agroforestry areas. The point-intercept method and exploration of weed vegetation varieties in agroforestry station constitute the research methodology. As a comparison station, this study was also conducted on teak monocultures that are commonly found at research sites.The quadratic form measuring 1 m x 1 m with 100 grids of 12 plots at each station was utilised to collect weed samples. Composition and dominance of species in agroforestry and monoculture were found to be distinct. 24 species from 12 families are used in agroforestry, while 12 species from 7 families are used in monoculture. The dominant invasive species in agroforestry is Ageratum conyzoides L. (34.39%), while in monoculture it is Synedrella nodiflora Gaertn (37.78%). The weed vegetation diversity index value in agroforestry and monoculture was 1.90 and 1.51,respectively, which is considered moderate. In contrast, the value of the Sorensen uniformity index, which was 36.84%, was considered to be low. Up to 26 species of vegetation have the potential to contribute to human survival.

Influence of Factors Determining Weeds’ Plant Tissue Reaction to the Electric Pulse Damage Impact

Due to the emerging danger to the life of animals and people, today there is a turn to safe technologies for controlling weeds by physical methods, both from the point of view of ecology and food safety, which include the destruction of plants using an electric current, in particular, high-voltage electrical pulses. The purpose of the study presented in the article is to identify and evaluate the effect of high-voltage electrical pulses on the irreversible damage to the intracellular structures of the plant tissue of weeds and unwanted grasses during their electric weed control, characterizing and evaluating the parameters and modes associated with such processing. Experimental studies were carried out using a laboratory experimental setup that consists of a pulse voltage generator, a control circuit for a spherical forming spark gap, and schemes for measuring the electrical resistance of the plant tissue of the weed sample. The lesion level made it possible to control the depth of irreversible damage to the internal structure of the plant tissue of weeds by measuring its tolerance (the conductivity of the tissue increased with increasing damage to the cellular components of the tissue).The irreversible damage to the plant tissues of weeds for weeds of various biological groups, which is characterized by reaching the value of at least 4.0–7.5 degrees of damage to their tissues, can be acted on them with high-voltage electrical pulses in the treated tissue of an electric field intensity of at least 3.74 kV/cm, while ensuring specific processing electric energy for the reliable processing of weeds: for Euphórbia virgáta, thise quals 5.2…17.5 J/cm3; for Amaránthus retrofléxus, it is 3.5…7.7 J/cm3; for Cirsium arvense, it is 2.7…10.9 J/cm3;for Sónchus arvénsis, it is 3.7…15.8 J/cm3; and for Lactúca tatárica, it is 3.3…8.1 J/cm3.

Potential Risk of Residues From Neonicotinoid-Treated Sugar Beet Flowering Weeds to Honey Bees (Apis mellifera L.).

In 2018 the European Union (EU) banned the three neonicotinoid insecticides imidacloprid, clothianidin (CLO), and thiamethoxam (TMX), but they can still be used if an EU Member State issues an emergency approval. Such an approval went into effect in 2021 for TMX-coated sugar beet seeds in Germany. Usually, this crop is harvested before flowering without exposing non-target organisms to the active ingredient or its metabolites. In addition to the approval, strict mitigation measures were imposed by the EU and the German federal states. One of the measures was to monitor the drilling of sugar beet and its impact on the environment. Hence we took residue samples from different bee and plant matrices and at different dates to fully map beet growth in the German states of Lower Saxony, Bavaria, and Baden-Württemberg. A total of four treated and three untreated plots were surveyed, resulting in 189 samples. Residue data were evaluated using the US Environmental Protection Agency BeeREX model to assess acute and chronic risk to honey bees from the samples, because oral toxicity data are widely available for both TMX and CLO. Within treated plots, we found no residues either in pools of nectar and honey crop samples (n = 24) or dead bee samples (n = 21). Although 13% of beebread and pollen samples and 88% of weed and sugar beet shoot samples were positive, the BeeREX model found no evidence of acute or chronic risk. We also detected neonicotinoid residues in the nesting material of the solitary bee Osmia bicornis, probably from contaminated soil of a treated plot. All control plots were free of residues. Currently, there are insufficient data on wild bee species to allow for an individual risk assessment. In terms of the future use of these highly potent insecticides, therefore, it must be ensured that all regulatory requirements are complied with to mitigate any unintentional exposure. Environ Toxicol Chem 2023;00:1-11. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Increasing Array of Herbicides for Post-emergence Weed Control and Seed Yield in Maize (Zea mays Linn)

Study was conducted at the Institute of Agricultural research and Training (IAR&T) Ilora (Derived savanna agro-ecology) substation in the rainy seasons of 2014 and 2015, to appraise herbicides for post-emergence weed control and increase array of herbicides for weed control in maize. Weed samples were taken from a three-year fallow field before land preparation. Herbicides under evaluation were assigned to 3 x 3 plots at different rates. These were arranged in randomized complete block design (RCBD) with three replicates. The results showed that initial weed flora richness were 22% and 78% grass and broad-leaved weeds respectively. These were found in five (5) plant families. All the weeds sampled were annuals. Narrow annual weed spectrum, described continuous cropping activities in the location. Herbicides improved plant height by 36 to 50% compared to weed infested maize plants. Though phyto-toxicity was evident at three and twenty-one days after treatment (DAT), ranging from 1/10 to 3.79/10 and 2/5 and 3.67/10 correspondingly when visually rated (0 – 10 scale). Notwithstanding, herbicides gave impressive weed control rate (WCR) at 21 DAT (6.7/10 - 8.7/10), with evidence of superior weed control efficiency (WCE >80%) at harvest across herbicide treated plots relative to weedy control plots. 2,4-D DMA (0.86 kg ai/ha), Fluroxypyr methyl (0.40 ai kg/ha), 2,4-D + Dicamba (0.68 + 0.24 kg ai/ha) and 2,4-D DMA (2.58 kg ai/ha) had <30% relative yield loss (RYL%) with comparable seed yield compared to the highest recorded in weed-free plot (13.29 t/ha). Plant height at 8 WAS (weeks after sowing) had significant inverse relationship with weediness at 5 WAS and weed dry weight at harvest (- 0.62). Consequently, early weed control is essential for maize performance. On the other hand, plant height enhanced weed control efficiency at harvest (0.62). Tall plants have tendency to reduce relative yield loss (RYL %) as they were inversely related 1 (- 0.42). Comparable WCE% (83 -99%) in herbicide treated plots reduced weed growth by about 88%. Hence, lower rate of herbicides with <30% phyto-toxicity level should be considered to increase array of herbicides for post-emergence weed control, sustainable maize production and environmental friendliness.

Molecular detection of rice tungro bacilliform virus (RTBV) on weed host in South Sulawesi

Rice tungro bacilliform Virus (RTBV) is one of the viruses that cause tungro disease in rice plants causing leaf yellow and plant stunting. Some weed species have also been described as potential hosts for RTBV in addition to rice. However, RTBV cannot be diagnosed in weeds only by looking at their morphological symptoms because weeds infected with RTBV do not show typical symptoms. Hence this research was conducted to detect the presence of RTBV molecularly on several weed hosts in rice fields in South Sulawesi. The polymerase Chain Reaction technique with coat protein gene-specific primers was used to detect RTBV. A total of 29 leaf samples consisting of 12 weed species collected from Sidrap, Pinrang, Maros, and Gowa were then extracted genomic DNA from the leaf samples for PCR analysis. The results of PCR analysis showed that weed samples that tested positive for RTBV were Panicum repens (Lawawoi/Sidrap), Echinochloa crusgalli (Lawawoi/Sidrap), Cyperus difformis (Lanrang/Sidrap), Echinochloa crusgalli (Palangga/Gowa), Fimbristilys miliacea (Lanrang/Sidrap), and Eleusine indica (Lawawoi/Sidrap) which were indicated by the presence of RTBV virus DNA fragments with 430 bp in length in all these weeds. Weeds infected by RTBV formed 2 clusters. The first cluster consisted of RTBV in P.repens and E.crusgalli from Lawawoi/Sidrap, RTBV in C.difformis and F.miliacea from Lanrang/Sidrap, and RTBV in E.indica from Palangga/Gowa. At the same time, the second cluster consisted of RTBV in E.indica from Lawawoi/Sidrap.

Identifikasi Jenis Gulma di Areal Pertanaman Pala (Myristica Fragrans) di Negeri Hatu Kecamatan Leihitu Barat Kabupaten Maluku Tengah

One of the agricultural commodities in Indonesia which is a source of foreign exchange for the country is nutmeg. The nutmeg plant is a plant whose all parts can be widely utilized both on an industrial scale and to meet community needs. The yield of nutmeg is an export commodity that is very important for increasing the country's foreign exchange, but the lack of proper cultivation techniques, especially maintenance, results in the process of growth and production of nutmeg plants often experiencing disturbances. In addition there are also disturbances that come from wild plants called weeds. Weeds grow side by side with nutmeg plants, thereby disrupting the growth process of nutmeg plants and reducing nutmeg production. One of the causes of the decrease in nutmeg production in every planting area in Negeri Hatu, Central Maluku Regency, is weeds. Weeds are present in every nutmeg plantation area. The hypothesis put forward in this study is that there are various types of weeds, there are dominant weeds in the planting area, there are suggestions for proper weed control. This study uses the "vegetation survey" method to collect data with field observations. In carrying out the vegetation analysis, the quadratic method was used with sample plots measuring 1 m x 1 m, on 6 nutmeg trees and on each nutmeg tree 3 weed samples were taken so that a total of 18 weed samples were taken under the nutmeg plant canopy Quantitative data / primary data includes density , frequency and biomass. Observation of weeds was carried out destructively, namely the types of weeds in the sample plots were removed to calculate the individual and the biomass of each type.Keywords: vegetation analysis, dominant weeds, nutmeg