Weed Eradication Research Articles

The Impact of Integrated Weed Management Practices on Nutrient Uptake in Rice (Oryza sativa L.)

The study investigated the impact of integrated weed management practices on nutrient uptake in rice (Oryza sativa L.) and weeds at 90 days after transplanting (DAT) over the 2022 and 2023 growing seasons at the Crop Research Centre (CRC) farm of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut. Various weed control strategies, including the application of pre-emergence and post-emergence herbicides combined with manual weeding, were evaluated for their effectiveness in enhancing the uptake of essential nutrients such as nitrogen (N), phosphorus (P), and potassium (K) by rice, while also reducing nutrient loss to weeds. Among the strategies tested, the combination of Pyrazosulfuron at 150 g active ingredient per hectare (a.i. ha⁻¹) as a pre-emergence herbicide and Penoxsulam at 22 g a.i. ha⁻¹ as a post-emergence herbicide, supplemented with one manual weeding at 40 DAT, proved to be the most effective. This approach resulted in the highest nutrient uptake by rice and the lowest nutrient uptake by weeds. In this treatment, nitrogen uptake in the rice grains reached 62.7 kg per hectare in 2022 and 67.4 kg per hectare in 2023, significantly outperforming other treatments. The weed-free treatment, which involved complete weed eradication, also demonstrated high nutrient absorption, highlighting the importance of thorough weed control for optimal rice growth. Conversely, the untreated weedy check, where no weed control was implemented, led to the highest nutrient uptake by weeds, severely limiting the availability of nutrients for the rice crop. Manual weeding alone, without the use of herbicides, showed moderate effectiveness but was less efficient compared to the integrated approach combining herbicides and hand weeding.

Effect of different weed control techniques on the leaf yield and nutritional qualities of Ocimum sanctum

AbstractOcimum sanctum is a leaf‐vegetable and spice crop with several nutritional, therapeutic, and curative properties. Economic losses due to weeds have posed a major challenge to farmers, who have adopted different techniques to manage weeds without regard to its effect on the crop's nutritional qualities. The objective of this study was to investigate the effect of weed control techniques on weed eradication, leaf yield, and nutritional qualities of O. sanctum. Nine weed control techniques comprising black, red, and transparent polyethylene mulches, rice husk and sawdust mulches, daily removal of weed (DROW), hoe‐weeded, application of Haloxyfop post‐emergence herbicide spray (PEHS), and un‐weeded were investigated in a randomized complete block design with three replications. Significant variations in leaf‐yield and nutritional qualities among the different weed control techniques were recorded. Leaf yield was higher in plots treated with rice husk and black polyethylene mulches. Haloxyfop PEHS and transparent polyethylene mulch were superior in enhancing the proximate and vitamin contents of O. sanctum while black polyethylene and DROW were more efficient in weed control compared with the other weed control techniques. The use of polyethylene mulch as an effective weed management option offers numerous benefits for agriculture and gardening. Its ability to conserve moisture, suppress weed growth, and improve the crop microclimate, makes it a sustainable and cost‐effective option for farmers globally. Additionally, the use of herbicide to exploit plant biosynthetic pathways could lead to the unearthing of chemical innovations that could in addition to eradicating weed, also improve the nutritional qualities of crop.

Effectiveness of emulan LVA as adjuvant herbicide for weed eradication volunteer oil palm seedling (VOPS) in oil palm plantations

One of the important and detrimental Plant Pest Organisms (PPO) that appear in the oil palm area is weeds. VOPS is a weed that is difficult to control using the herbicide spray method. Tests were carried out on 56 herbicide formulations for VOPS eradication, based on the test results, formulations using IPA-Glyphosate (various trademarks) + LVA Emulan could completely kill VOPS of various sizes. The concentration that is effective in completely killing VOPS is IPA-Glyphosate 15 ml/L + Emulan LVA 2 ml/L. Eradication of VOPS needs 8 weeks after application (WAA). The process of VOPS death is characterized by drying and rotting of the young leaves or shoots of the lance leaves and followed by drying of all the palm fronds and when split crosswise the apical shoots (growing points) look brownish yellow and have a foul odor.

ТЕХНИКО-ТЕХНОЛОГИЧЕСКИЕ АСПЕКТЫ ЛАЗЕРНОЙ ПРОПОЛКИ РАСТЕНИЙ

The creation of technologies and autonomous robots for laser weeding of agricultural crops is a promising and relevant direction in the fight against weeds, which will allow for high-precision and targeted processing of crops without the use of herbicides. (Research Purpose) The research purpose is analyzing technologies and technical means for laser weeding of plants. (Materials and methods) Using the aspect approach, the analysis of domestic and foreign scientific publications on the use of laser technologies in agricultural practice was carried out. (Results and discussion) It has been established that laser weeding technology includes several key components: mobile robotic devices, computer vision systems for plant recognition, navigation systems for precise positioning of robotic platforms in field conditions and laser systems for high-precision weed eradication. Artificial intelligence and deep learning methods are preferred for plant recognition. CO2 lasers, fiber and diode lasers are mainly used as laser energy sources. The most effective solution for laser weeding is a ground-based mobile robotic platform with a block-modular design, which is equipped with integrated laser systems for processing plants, weed recognition systems, as well as various navigation systems. (Conclusions) It is determined that carbon dioxide lasers with wavelengths of 9.3, 10.2 and 10.6 micrometers and power up to 100 watts are used for laser weeding. Diode lasers operate in the wavelength range of 450-900 nanometers with pulses lasting up to tenths of a second and a power of 5-25 watts, forming a contact spot measuring 0.5-2.5 millimeters. It has been established that fiber lasers with high peak power of short pulses and compact dimensions with a wavelength in the visible and near infrared ranges of 0.75-1.4 micrometers are promising for laser weeding. To treat weeds, carbon dioxide lasers require the least amount of energy - up to 125 Joules per weed at a wavelength of 10,600 nanometers. When using wavelengths of 1908, 940 and 532 nanometers (fiber, diode and solid-state lasers), 230, 237 and 1400 Joules are spent per weed. It is also determined that the height of treatment of weeds with a laser beam is 0.3-0.6 meters.

Chenopodium murale L.: A Weed of Medicinal Importance - A Brief Review

Weeds are considered a great threat to crops. So weed eradication is an important task to increase crop yield. Chemical weed control in various crops decreases their nutritive potential. To overcome this problem to some degree, it is suggested to use these weeds instead of destroying them. Keeping this in view, such losses can be compensated by exploring their medicinal utility and identifying their future medicinal prospects. Chenopodium murale L. (Amaranthaceae) is an annual weed growing throughout the world. This review aims to summarize the reported pharmacology and phytochemistry of C. murale to explore its medicinal utility and identifying their future medicinal prospects. The review was done by literature collection from textbooks and online databases without a time limit. The weed name was confirmed by ‘The Plant List’. C. murale extracts, their isolated active constituents, and nanoparticles have been reported for various pharmacological actions like hepatoprotective, antihypertensive, antidiabetic, antidiarrheal, anticancer, antimicrobial, nematicidal, antioxidant, and cytotoxic. The pharmacological effects of C. murale may be due to the presence of secondary active metabolites such as phenolic acids, flavonols, terpenes and terpenoids, flavonoids and a steroidal glycoside. Reported phytochemistry and pharmacology suggest that C. murale could be an important medicinal agent for leishmaniasis, hypertension, infections and liver diseases. However, further studies are warranted.

Can honey bees be used to detect rare plants? Taking an eDNA approach to find the last plants in a weed eradication program

AbstractThe detection of rare taxa, crucial to conservation and biosecurity, presents many challenges that emerging technologies have the potential to address or avoid. Analysis of environmental DNA (eDNA) is a promising tool for the detection of rare species, especially when applied in a way that exploits natural processes to accumulate biological material (natural aggregation). This study investigated the potential of using honey bees as aggregators of pollen eDNA to detect Chrysanthemoides monilifera subsp. monilifera (boneseed), an introduced species targeted for eradication in Western Australia. We developed a species‐specific polymerase chain reaction (PCR)‐based assay that detected boneseed pollen at levels as low as 70 grains per million in a constructed pollen mixture. The assay was successfully used on wild‐caught bees from large boneseed populations, confirming they collect boneseed pollen. However, our results did not detect boneseed DNA in honey bee pollen collected from hive pollen traps near isolated boneseed plants. We hypothesize that a combination of low abundance of boneseed individuals, vast alternative flower resources at the time of boneseed flowering, and honey bee behavior and ecology may have led to lack of detection. We propose ways in which future work using honey bees to detect rare species can be improved. We also outline how other eDNA substrates (e.g., air and water samples) could be used with the PCR assay we have developed. More broadly, our work highlights the potential of eDNA techniques to detect rare species in biosecurity and conservation contexts and contributes to the development of pollinator‐based detection.

First Report of Karelinia caspia (Pall.) Less as a new host of Orobanche cumana Wallr. in Xinjiang, China.

Sunflower broomrape (Orobanche cumana Wallr.) is a holoparasitic plant species which mainly parasitizes a few species of the Asteraceae in the wild and is exclusively found growing on sunflower in agricultural fields (Fernández-Martínez et al. 2015). O. cumana is a serious threat to sunflower production in Xinjiang and Inner Mongolia (Shi et al. 2015). Karelinia caspia (Pall.) Less. (Asteraceae) is an ecologically important plant species occurring across the desert ecosystems of Russia, Central Asia, and northwest China. It plays an important role in reducing wind erosion and desertification (Xu et al. 2018). During the 2018 and 2019 growing seasons, sunflower broomrape was observed parasitizing K. caspia in non-cultivated areas adjacent to sunflower fields near Beitun city (87°51'E, 47°15'N) in Xinjiang, China. Sunflower broomrape plants were identified morphologically as O. cumana according to Pujadas-Salvà and Velasco (2000). The host plants were identified morphologically as K. caspia according to Lin et al (1979). The ribosomal DNA internal transcribed spacer (ITS) and the trnL-F region of the parasite were amplified by PCR using primer pairs ITS1/ITS4 and trnL-FF/trnL-FR, respectively (Taberlet et al. 1991; Anderson et al. 2004). The ITS sequence of the parasite (Accession No. MT795725.1) showed 100% identity (675bp out of 689bp) to that of O. cernua var. cumana (KC811228.1). The trnl-F sequence of the parasite (Accession No. ON843707) showed 98% identity (675 of 689 bp) to O.cernua var. cumana (KT387722.1). Multi-locus phylogenetic analysis of the two sequences showed clustering with sunflower broomrape. The ITS region of the parasite and host was were amplified by PCR using the primer pair ITS1F/ITS4R (Taberlet et al.1991), and the ITS sequences of the host (Accession No. MT791995.1) showed 99.86% identity (728bp of 802bp) to that of K. caspia (LN607483.1). Rhizotron and pot experiments were carried out to assess the parasitic relationship between O. cumana and K. caspia. In the rhizotron experiment, 2-week-old seedlings of K. caspia were inoculated with sterilized 400 O. cumana seeds in a 15-cm petri dish filled with a sponge overlaid with glass fiber filter paper. The parasitic state of O. cumana was observed 9 days after inoculation. In another trial, seeds of K. caspia were sowed in 2-L and 4-L pots containing sand-vermiculite-compost (1:1:1 v:v:v). These pots were artificially inoculated with 50 mg of O. cumana seeds per 1 kg of substrate. After 20 and 70 days, corresponding to the early parasitic and flowering stages, respectively, of O. cumana, K. caspia plants were uprooted from the media and washed carefully. The parasitic relationship was confirmed by the attachment position of the broomrape to the K. caspia root. To our knowledge, this is the first report of O. cumana parasitizing K. caspia in Xinjiang, China. This phenomenon means that sunflower broomrape can raise up seed on a newly recognized host. Weed eradication in and near sunflower fields is a key measure to control sunflower broomrape.

Overcoming field variability: unsupervised domain adaptation for enhanced crop-weed recognition in diverse farmlands.

Recent developments in deep learning-based automatic weeding systems have shown promise for unmanned weed eradication. However, accurately distinguishing between crops and weeds in varying field conditions remains a challenge for these systems, as performance deteriorates when applied to new or different fields due to insignificant changes in low-level statistics and a significant gap between training and test data distributions. In this study, we propose an approach based on unsupervised domain adaptation to improve crop-weed recognition in new, unseen fields. Our system addresses this issue by learning to ignore insignificant changes in low-level statistics that cause a decline in performance when applied to new data. The proposed network includes a segmentation module that produces segmentation maps using labeled (training field) data while also minimizing entropy using unlabeled (test field) data simultaneously, and a discriminator module that maximizes the confusion between extracted features from the training and test farm samples. This module uses adversarial optimization to make the segmentation network invariant to changes in the field environment. We evaluated the proposed approach on four different unseen (test) fields and found consistent improvements in performance. These results suggest that the proposed approach can effectively handle changes in new field environments during real field inference.

3D MODEL OF THE MECHANICAL PART OF A WEED RECOGNITION SYSTEM IN AN AGRICULTURAL ROBOT IN 3D EXPERIENCE ENVIRONMENT

The damage from weeds in the cultivation of agricultural crops is ubiquitous and they adversely affect the yields of agricultural production. The soil conditions of the places where the crops are grown deteriorate. Contribute to the development of diseases and the enemies on them. Apart from this, it is difficult to carry out mechanized processing and harvesting activities. Weeds also worsen the very quality of the harvested produce. That is why the availability of a recognition system to the agricultural robot is essential to reduce the adverse influence. It is part of a system of control and destruction. In this weed recognition system, an essential element is a robotic arm to enable a camera to perform video surveillance.The aim of this paper is to modelling only the mechanical anchorage system for weed recognition elements that it does not interfere with the other elements with which it interacts. To be as effective as possible, this system must be as close as possible to the plants and at the same time close to the weed eradication system in agricultural robot.A three-dimensional model of the weed recognition mechanical parts from system is discussed in the paper. It is designed in a 3D Experience environment, taking into account the parameters necessary for the movement of the system. Strength sizing of the structure and working simulations of the model were made.

Failure Analysis of 9-Tyne Cultivator in Different Soil Conditions by Using FEM

We have all seen development over the past few decades in virtually every industry. Agriculture is a linked area of development. Nowadays, large farmers use cutting-edge machineries like tractors, cultivators, harvesters, and modern farm equipment. In nations like India, over 70% of farmers still practise conventional farming. They also require more advanced farming tools. This essay analyses the 9-tyne cultivator in various soil conditions and studies failure. Using a cultivator, which experiences stress through contact with the soil, is a crucial piece of agricultural equipment for preparing the soil. When the Tyne works as a cultivator and is in contact with the soil. We can lessen the strain caused by altering the cultivator's design. First, an accurate CAD model has been created using Pro/E CAD software to analyse this Tyne mechanism using FEM. The stresses were then calculated using FEM analysis utilising ANSYS software. The process of optimization in the advanced cultivator tool system was conceptually created, made, and subjected to research and analysis after failure. The soil bed preparation and varied crop patterns are both considered in the programme testing of a field performance. The greatest benefit was achieving high weed eradication effectiveness.

Use of a Pair of Pulse-Charged Grounded Metal Nets as an Electrostatic Soil Cover for Eradicating Weed Seedlings

An electrostatic technique was developed to generate a simple physical method to eradicate weeds in crop fields. The proposed apparatus consisted of double-expanded metal nets connected to a pulse-charging type negative voltage generator and a grounded line. The two metal nets were arranged in parallel at an interval (6 mm) that caused no arc (spark) discharge between the negatively charged metal net (NC-MN) and the grounded metal net (G-MN). The paired nets were used as a soil cover to zap weed seedlings emerging from the ground. As plant seedlings are biological conductors, the seedling was subjected to an arc discharge from the upper metal net (NC-MN) when it emerged from the soil and passed through the lower net (G-MN). The discharge was strong enough to destroy the seedling with a single exposure. The arc treatment was highly effective for eradicating successively emerging mono- and dicotyledonous weed seedlings, regardless of the number of coexisting weeds or the area of the netted field. Thus, the present study provides a simple and reliable weed eradication method that could be integrated into a sustainable crop production system.

Finite Element Analysis (FEA) of blade weed design using Ansys workbench

Manual, semi-conventional, and conventional weed eradication are the three forms of weed eradication utilized. Farmers benefit greatly from the usage of weeding equipment in combating pests in the fields. The blade you use determines how successful you are at weeding. As a result, it is required to examine the weeding weeds blade. With a tetrahedral mesh, simulation utilizing the finite element analysis approach allows for the optimization of design, computation, and prediction of material strength. The goal of this research was to figure out how much von Mises's stress, deformation, and safety factor were worth. ANSYS Workbench software was used to simulate various loadings of 10N, 25N, and 50N. The highest von Mises stress created by simulation of modelling weed blades at 10N, 25N, and 50N loads is around 2.95x10-2 MPa, 7.38x10-2 MPa, and 0.14755 MPa, respectively. Each of the safety factors is 15, and the maximum deformation value is 4.26x10-7mm; 1.06x10-6mm; 2.13x10-6mm. The safety factor indicates that the weed weeding knife design is safe to use up to 50N loading.

AGROSMART : A Real-Time Cultivation Predication Robot System using IoT

Agriculture is the primary source of income for approximately 70% of Indians. As a result, India's agricultural system should be upgraded in order to lessen farmers' efforts. In the agricultural field, various activities such as sowing, weeding, weed cutting, ploughing, and so on are carried out. Seeding, ploughing, and weed eradication are all very fundamental and important operations. However, the current sowing, ploughing, and plant cutting procedures are troublesome. Seed sowing machinery is quite tough and inconvenient to operate. As a result, the need to build equipment that would lessen the farmers' efforts. During sowing, this method employs a monitoring system that seeks to fall seeds at a certain location with the set spacing between both seeds and lines. Weed control is aided by the robotic arm. As a result, in this automatic machine, the flaws of the present system will be successfully eliminated.

UAV-Supported Forest Regeneration: Current Trends, Challenges and Implications

Replanting trees helps with avoiding desertification, reducing the chances of soil erosion and flooding, minimizing the risks of zoonotic disease outbreaks, and providing ecosystem services and livelihood to the indigenous people, in addition to sequestering carbon dioxide for mitigating climate change. Consequently, it is important to explore new methods and technologies that are aiming to upscale and fast-track afforestation and reforestation (A/R) endeavors, given that many of the current tree planting strategies are not cost effective over large landscapes, and suffer from constraints associated with time, energy, manpower, and nursery-based seedling production. UAV (unmanned aerial vehicle)-supported seed sowing (UAVsSS) can promote rapid A/R in a safe, cost-effective, fast and environmentally friendly manner, if performed correctly, even in otherwise unsafe and/or inaccessible terrains, supplementing the overall manual planting efforts globally. In this study, we reviewed the recent literature on UAVsSS, to analyze the current status of the technology. Primary UAVsSS applications were found to be in areas of post-wildfire reforestation, mangrove restoration, forest restoration after degradation, weed eradication, and desert greening. Nonetheless, low survival rates of the seeds, future forest diversity, weather limitations, financial constraints, and seed-firing accuracy concerns were determined as major challenges to operationalization. Based on our literature survey and qualitative analysis, twelve recommendations—ranging from the need for publishing germination results to linking UAVsSS operations with carbon offset markets—are provided for the advancement of UAVsSS applications.

Weed interference capacity on soybean yield

Among biological factors, weeds are the most important limiting factor for crop yields, as well as increasing production costs. The aim was to determine the influence of control and coexistence of weed community on soybean crop yield and to define the period before interference, the critical period of interference prevention and the total period of interference prevention, with the comparative use of chemical and mechanical methods for weed eradication. The study was conducted in an experimental field in the 2018/2019 harvest. A randomized block with four replications was implemented as experimental design, using two methods for control. The evaluated periods were 0-10, 0-20, 0-30, 0-40, 0-50, 0-60 and 130 days after crop emergence. It was possible to observe that the use of the chemical method generated a higher yield compared to mechanical method. The period before the interference in both chemical and mechanical management was similar, approaching 20 days after crop emergence. The critical period of interference prevention was between 20-50 and 40.5 days after crop emergence in chemical and mechanical methods, respectively. The total period of interference prevention was extended to 50 and 40.5 days after crop emergence in chemical and mechanical methods, respectively. The reduction in productivity due to weed interference was 1639 kg ha-1 (55%)and 947 kg ha-1 (34.6%) in chemical and mechanical methods, respectively.

An integrated inter- and intra-row weeding system for row crops

Weeding is critical to eliminate non-native plants that compete with main crops and adversely affect their production quality and quantity. Numerous prototypes exist for inter-row weeding but very limited for intra-row weed eradication. This study developed a tractor drawn integrated inter- and intra-row weeding (IIIRW) system for field crops. Active rotary tines were used for intra-row weeding and passive tines for inter-row weeding. Optimum operational configurations were obtained with rigorous repeated soil bin experiments, and developed system was evaluated for three growing seasons (2017–19) in field grown maize (Zea mays L.) and pigeon pea (Cajanus cajan (L.) Millsp.) crops. Optimum ratios of intra-row tine rotary speed to forward speed (u/v) were in the ranges of 0.8–1.3 that lead to weed mortality of 88.4 % (Buried: 8.5 %, Uprooted: 79.9 %), negligible intact weeds, and plant damage (Pd) within 6 %. Sole inter-row weeding operation resulted up to 78.1 % of weed mortality (Buried: 18.1 %, Uprooted: 60.0 %) and negligible Pd. Overall weed mortality with the IIIRW system was 92.8 % (Buried: 9.5 %, Uprooted: 83.3 %) in maize and 84.1 % (Buried: 7.6 %, Uprooted: 76.5 %) in pigeon pea crops. Results suggest suitability of the IIIRW system for a range of similar crops for field capacity in ranges of 0.22–0.26 ha/h at recommended operating speeds within 0.50–0.56 m/s. The IIIRW system requires a single prime mover and could be potentially economical and efficient technology for field weeding operations.

The SCREENING OF HERBICIDES FOR EFFECTIVE CONTROL OF WEEDS IN SOYBEAN (Glycine max L.)

Little is known about best herbicidal weed option for weed eradication in soybean in agro-climatic circumstances of Sargodha, Punjab, Pakistan. A two year field study was accomplished at College of Agriculture experimental site Sargodha in spring seasons of 2018 and 2019 to evaluate the efficacy of different herbicides adjacent to major weeds present in soybean. The study consisted of 8 herbicide treatments including two pre-emergence herbicides (pendimethalin at 489.1 g a.i. ha-1, pendimethalin + S-metolachlor at 731.1 g a.i. ha-1) which are applied immediately after sowing and six post-emergence herbicides (oxyfluorfen at 237.1 g a.i. ha-1, metribuzin at 518.7 g a.i. ha-1, quizalofop-p-ethyl at 148.2 g a.i. ha-1, acetochlor at 741 g a.i. ha-1, halosulfuron at 37 g a.i. ha-1and topramezone at 21.5 g a.iha-1) which were used 25 days subsequent to sowing. In contrast to control, all herbicides have shown significant decline in weed density (up to 94%) and dry weight (up to 88%); and caused significant increases in plant height (up to 85%), pod bearing branches (up to 77%), number of pods per plant (up to 83%), 100-seed weight (up to 37%) and seed yield (up to 160%) of soybean. Among herbicides, topramezone at 21.5 g a.i ha-1 gave significantly the highest (1234 and 1272 kg ha-1 in the year 2018 and 2019) seed yield of soybean and HEIs (1.28 and 1.03 in year 2018 and 2019, respectively). However, oxyfluorfen at 237.1 g a.i. ha-1, pendimethalin + S-metolachlor at 731.1 g a.i. ha-1, pendimethalin at 489.1 g a.i. ha-1, quizalofop-p-ethyl at 148.2 g a.i.ha-1 followed it. The regression analysis depicted a significant negative moderate relationship of soybean seed yield with weed dry weight (R2 = 0.7074), and pods per plant (R2 = 0.7012) was proved to be the main yield component responsible for higher yield of soybean.

Edge detection for weed recognition in lawns

The rapid propagation of weeds is a major issue for turfgrass management (both ornamental and sports turf). While pesticides can ensure weed eradication, they pose a risk to human health and the environment. In this context, the early detection of weeds can allow a dramatic reduction in the amount of pesticide required. Here we present the use of edge detection techniques to identify the presence of these invasive plants in ornamental lawns and sports turf. Regarding the former, images from small experimental plots in the facilities of IMIDRA were used while images for the latter were taken on a golf course. Up to 12 different filters for edge detection were tested on the images collected. Aggregation techniques, with a range of cell values, were applied to the results of the three most effective filters (sharpening (I), sharpening (II), and Laplacian) to minimise the number of false positives. After the tests with different cell sizes, two filters were selected for more in-depth analysis. Box plots were selected to define the best cell size and identify the filter with the best performance. The sharpening (I) filter and the aggregation technique with the minimum value and a cell size of 10 offered the best results. Finally, we determined the most appropriate threshold value on the basis of the number of false positives, false negatives, and derived indexes (Precision, Recall, and F1-Score). A threshold of 78 gave the best performance. The results achieved with this methodology differed slightly between ornamental and sports turf.

Long term monitoring of recruitment dynamics determines eradication feasibility for an introduced coastal weed

Bitou bush (Chrysanthemoides monilifera subsp. rotundata) is a Weed of National Significance in Australia and has impacted a significant portion of the eastern coastline. Its discovery in Western Australia was, therefore, a cause for concern. Assessment and control of the isolated and well-defined population began in 2012. To assess the feasibility of eradication in Western Australia as a management outcome for bitou bush, we applied a rigorous data-driven quantification and prediction process to the control program. Between 2012 and 2018 we surveyed over 253 ha of land and removed 1766 bitou bush plants. Approximately 97 person-days were spent over the six years of survey. We measured the seed bank viability for five years starting in 2013, with the 2017 survey results indicating a decline of mean viable seeds/m2from 39.3 ± 11.4 to 5.7 ± 2.2. In 2018 we found only ten plants and no newly recruited seedlings in the population. No spread to other areas has been recorded. Soil core studies indicate that the soil seed bank is unlikely to persist beyond eight years. Eradication of the population in Western Australia, defined as five years without plants being detected, therefore remains a realistic management goal. The information generated from the documentation of this eradication program provides invaluable insight for weed eradication attempts more generally: novel detection methods can be effective in making surveys more efficient, all survey methods are not entirely accurate and large plants can escape detection, bitou bush seeds persist in the soil but become effectively undetectable at low densities, and migration of seed was unquantifiable, possibly compromising delimitation. Continued monitoring of the Western Australian population will determine how much of a risk these factors represent to eradication as the outcome of this management program.

Field Performance Evaluation of Power Weeder for Paddy Crop

Weeds are the main significant constraints in paddy production. Weed eradication by using herbicides and weedicides pronounced simple and fast method but is restricted due to its adverse effects on both environment as well as human beings. To overcome these limitations, mechanical weeding can be selected as appropriate weed control measure.Based on this, a modified power weeder was tested for weed control in upland paddy at 20 and 45 days after sowing (DAS) andthe performance was compared with traditional hand weeding and manual operated mechanical weeder (Ambika paddy weeder). The modified power weeder show well prominence in weeding for upland paddy at 20 and 45 DAS and fuel efficient (0.63 to 073 l/h).The power weeder was found at par with the Ambika paddy weeder with a weeding efficiencyof 74.22 % and 86% at 20 and 45 DAS respectively. There was no significant variation in field efficiency for Ambika paddy weeder at 20 & 45 DAS, but the highest field efficiency was shown by paddy power weeder as 70% for 45 DAS.The energy consumption was more in paddy power weeder than Ambikapaddy weeder as 493.64 and 452.40 MJ/ha at20 and 45DAS respectively. The cost of operation per hectare with power weeder amounted to ₹928/-and₹850/-against Ambika paddy weeder as₹2,617/- and₹2,346/- for 20 and 45 DAS respectively. The machine also depicted the energy-cost as 1.88 and 1.87 at 20 and 45 DAS respectively. Whereas the hand weeding showed the highest values in weeding efficiency and field efficiency at 20 and 45 DAS as it was an ideal method of weed control exceptforthe cost of operation.