I developed a weeding-duration model for Sakhalin fir （Abies sachalinensis （Fr. Schmidt） Masters） plantations that employs a generalized linear model. The number of years following planting that weeding is necessa...I developed a weeding-duration model for Sakhalin fir （Abies sachalinensis （Fr. Schmidt） Masters） plantations that employs a generalized linear model. The number of years following planting that weeding is necessary is the response variable, and elevation, slope steepness, maximum snow depth, annual precipitation, geology, soil, site index, slope aspect, and vegetation type are explanatory variables. Among the explanatory variables, geology, soil, slope aspect, and vegetation type are categorical data. A Poisson distribution is assumed for the response variable, with a log-link function. Elevation, slope steepness, maximum snow depth, annual precipitation, site index, and vegetation type had a significant effect on weeding duration. Among the eight models with the smallest Akaike information criterion （AIC）, I chose the model with no multicollinearity among the explanatory variables. The weeding-duration model includes site index, maximum snow depth, slope steepness （angle） and vegetation type as explanatory variables; elevation and annual precipitation were not included in the selected model because of multicollinearity with maximum snow depth. This model is useful for cost-benefit analyses of afforestation or reforestation with Abies sachalinensis.展开更多
This study quantified the effect of weeding frequency and weeding schedules on weeding operation time in a sugi(Cryptomeria japonica)plantation stand.A weeding operation time estimation model was developed;then the cu...This study quantified the effect of weeding frequency and weeding schedules on weeding operation time in a sugi(Cryptomeria japonica)plantation stand.A weeding operation time estimation model was developed;then the cumulative weeding operation time after six growing seasons was simulated using the developed model.The developed model included weed height,relative height of weeds to sugi,and initial planting density.The simulated cumulative weeding operation time decreased approximately 6%for each one-treatment decrease in weeding frequency.Under a three-treatment weeding frequency scenario,the simulated cumulative operation time when weeding was conducted during non-consecutive years was longer than that when weeding was conducted during three consecutive years.The results suggest that carrying out weeding treatment during consecutive years is the more effective for reduction of weeding costs.We conclude that weeding schedule as well as weeding frequency must be considered for reduction of weeding operation time.展开更多
The System of Rice Intensification (SRI) has been attributed to improvement in rice production with various attributes being accrued from application of the SRI Principles. The most notable are savings on water use an...The System of Rice Intensification (SRI) has been attributed to improvement in rice production with various attributes being accrued from application of the SRI Principles. The most notable are savings on water use and increase in yield. Alternate Wetting and Drying (AWD) has also paved way for mechanical weed control in paddy fields. One of the major constraints to adoption of SRI is the perceived increased labour input due to the careful transplanting and frequent weed control. This paper evaluates the effect of mechanization on labour input in SRI in comparison to the less mechanized farmer practice. In attempt to reduce drudgery in transplanting under SRI, the drum seeder was used to establish the rice crop by direct seeding. This was then followed by using SRI practices i.e. AWD and mechanical weeding. Direct seeding using a drum seeder was compared to transplanting in both SRI and the common farmer practice. Hand weeding was also evaluated and compared to mechanical weeding. Labour input cost was also compared to the income accrued from the yields. From the study, it was noted that direct seeding using the drum seeder reduced labour input by 97% compared to transplanting. This was possible in that in direct seeding, and there was no nursery preparation and management as in transplanting. The use of a mechanical weeder reduced labour input by 28.3% in relation to hand weeding. Labour input cost for SRI was cheaper (Kshs. 124,080 per hectare) compared to the common farmer practice (Kshs. 139,117.50 per hectare). There was more yield from the SRI practice (2.75 Ton/ha) compared to the common farmer practice (1.88 Ton/ha).展开更多
The experiment was conducted at agronomy farm of Sher-e-Bangla Agricultural University, Dhaka <span style="font-family:Verdana;">from</span><span style="font-family:;" "="&...The experiment was conducted at agronomy farm of Sher-e-Bangla Agricultural University, Dhaka <span style="font-family:Verdana;">from</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> November 2017 to April 2018 to investigate the influence of weeding regimes on the performance of white maize varieties. The experiment comprised two varieties </span><i><span style="font-family:Verdana;">viz</span></i><span style="font-family:Verdana;">. YANGNUO-3000 and PSC-121, designated as V</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> and V</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> respectively combined with four weed control treatments </span><i><span style="font-family:Verdana;">viz.</span></i><span style="font-family:Verdana;"> T</span><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;"> = No weeding, T</span><sub><span style="font-family:Verdana;">1</span></sub></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">= One hand weeding at 60 DAS</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">(days after sowing), T</span><sub><span style="font-family:Verdana;">2</span></sub></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">= two hand weeding at 40 DAS and 60 DAS and T</span><sub><span style="font-family:Verdana;">3</span></sub></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">= Weed free after 40 DAS. The experiment was laid out in RCBD (factorial) with three replications. PSC-121 showed the superior performance in terms of plant height, leaf number plant</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, number of grains cob</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> (468.75), 100 grains weight (35.0837 g), grain yield (8.28 t ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), stover yield (6.56 t ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) and harvest index (55.58%) over YANGNUO-3000. In </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">case of weed control treatments, the highest plant height, leaf number plant</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, number of grains cob</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> (464.54), 100 grains weight (37 g), grain yield (9.25 t ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) and stover yield (7.46 t ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:;" "=""><span style="font-family:Verdana;">) were reported from T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">. All the parameters studied were found lowest with T</span><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;">. However, in terms of interaction, no single interaction was superior </span></span><span style="font-family:Verdana;">to</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> other alternatives. But in most of the cases V</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed the highest values regarding the maximum plant height, leaf number plant</span></span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, number of grains cob</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:;" "=""><span style="font-family:Verdana;"> (494.97) and 100 grains weight (38 g). V</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed the highest grain yield (9.33 t ha</span></span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:;" "=""><span style="font-family:Verdana;">), whereas, V</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">T</span><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;"> showed the lowest grain yield (5.49 t ha</span></span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">). The lowest weed density and weed biomass (12.17 no. m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;"> and 4.33 g·m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:;" "=""><span style="font-family:Verdana;">) was recorded from T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">. The highest weed control efficiency (94.38%) was also recorded from T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">. In </span></span><span style="font-family:Verdana;">the </span><span style="font-family:;" "=""><span style="font-family:Verdana;">case of variety V</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> showed better performance in terms of weed density, weed biomass and WCE (46.32%).</span></span>展开更多
Chemical weeding in dry direct seeding fields of single cropping middle-late rice was studied in Huida vegetable farm of Huizhou City in 2012. The main treatment was herbicide（ pretilachlor ＋ bensulfuron-methyl,Yang...Chemical weeding in dry direct seeding fields of single cropping middle-late rice was studied in Huida vegetable farm of Huizhou City in 2012. The main treatment was herbicide（ pretilachlor ＋ bensulfuron-methyl,Yangguo and butachlor）,and the sub-treatment was application method（ soil treatments,seedling treatment and integrated treatment）. The results showed that 80 g pretilachlor ＋ bensulfuron-methyl（ 36% pretilachlor ＋ 4% bensulfuron-methyl） diluted with 50 kg water could be sprayed or 200 g Yangguo（ 23. 9% butachlor ＋ 1. 1% bensulfuron-methyl） mixed with 15 kg sandy soil could be broadcasted per 667 m2 on the sowing day or the second day under moist condition of soil,which could effectively control weeds in dry direct seeding fields of single cropping middle-late rice.展开更多
According to experiments in many years in Hebei Province, the research explored weed comprehensive control technology on millet fields in terms of application range, prevention rules, prevention object, agricultural c...According to experiments in many years in Hebei Province, the research explored weed comprehensive control technology on millet fields in terms of application range, prevention rules, prevention object, agricultural control, physical control, and chemical control and proposed specific methods and technological indices in order to provide technological references for comprehensive control on weeds of millet fields.展开更多
[Objective] The paper was to explore weed control measures in tobacco fields in Anshun City. [Method] Different treatments on weed control were conducted in tobacco fields in Anshun City, Guizhou Province, from 2017 t...[Objective] The paper was to explore weed control measures in tobacco fields in Anshun City. [Method] Different treatments on weed control were conducted in tobacco fields in Anshun City, Guizhou Province, from 2017 to 2019. [Result] Various treatments had no negative effect on tobacco plant growth in the field, and had different degrees of control effects on five dominant weeds, including Digitaria sanguinalis, Setaria viridis, Fagopyrum dibotrys, Commelina communis and Chenopodium album. White mulching film and 50% butralin·clomazone EC 160 m L/667 m^(2) + white mulching film had the worst performance, which had extremely significant or significant differences with other treatments. There was no sig-nificant difference among most treatments, and the overall effects were comprehensive(multi-factor) treatment > double factor treatment > single factor treatment. [Conclusion] Combination control is recommended in practical tobacco production.展开更多
It is well known that quackgrass is both very aggressive and persistent. In agriculture, many attempts have been made to eliminate this weed without success. Within the context of a sustainable agriculture, mechanical...It is well known that quackgrass is both very aggressive and persistent. In agriculture, many attempts have been made to eliminate this weed without success. Within the context of a sustainable agriculture, mechanical control of quackgrass represents an interesting alternative to chemical means. The use of a ＂C＂ shaped mounted tine cultivator, a rotary cross-harrow, and an ＂S＂ shaped trailed tine cultivator （alone or in combination） to control quackgrass in grassland was investigated. The rate of quackgrass present in each experimental plot was determined before and after the treatments using a one square meter quadrant. Also, the time required for each passage as well as the fuel consumption were computed. Results revealed that the fuel consumption and the time required by the ＂C＂ and ＂S＂ shaped tine cultivators to transport and expose the rhizomes to the sun on the soil surface highly depend on the quality of tillage during the first stubble passage. Also, subsequent tillage with the ＂C＂ shaped tine cultivator after a first passage with a rotary cross-harrow resulted in less fuel consumption and passage time. On the other hand, stubble and subsequent soil tillage with only the ＂C＂ shaped tine cultivator is the least successful method.展开更多
Aiming to solve problems in organic rice weeding a type of post-seat weeding machine was designed for rice paddies.The differences in the strengths and lengths of the root systems between the rice seedlings and the we...Aiming to solve problems in organic rice weeding a type of post-seat weeding machine was designed for rice paddies.The differences in the strengths and lengths of the root systems between the rice seedlings and the weeds were studied,and the motion track of the weeding wheel was analyzed to obtain the structural parameters of the weeding wheel.Then,the structural model of the weeding wheel was designed.The interaction process between the weeding wheel and soil in the paddy fields was simulated and analyzed based on the discrete element method,so as to investigate the working resistance change tendency of the weeding wheel and the orderliness of the soil disturbances.An orthogonal test was designed in this study,with three factors:the hoeing depth,the rotation rate of the weeding wheel,and the forward speed of the device.The influences of different operation parameters of the weeding machine on the weeding torque and soil disturbance speed were obtained based on a variance analysis of the test results.A multi-index comprehensive weighted scoring method was used to evaluate the simulation results.A soil bin test was conducted to verify the simulation results.Field experiments were carried out to test the working performance of the weeding machine.The comprehensive scoring results indicated that a better working performance of the weeding operation could be obtained when the hoeing depth was 50 mm,the rotation rate of the weeding wheel was 240 r/min,and the forward speed was 0.6 m/s.The results of the soil bin test were consistent with the simulation results.The results of the field experiment revealed that the weeding machine met the requirements for organic rice weeding.These results can provide a reference for the design of weeding machines for paddy fields.展开更多
Mechanical weeding not only avoids crop herbicide residue but also protects the ecological environment.Compared with mechanical inter-row weeding,mechanical intra-row weeding needs to avoid crop plants,which is conduc...Mechanical weeding not only avoids crop herbicide residue but also protects the ecological environment.Compared with mechanical inter-row weeding,mechanical intra-row weeding needs to avoid crop plants,which is conducive to causing a higher rate of seedling damage.In order to realize maize(Zea mays L.)intra-row weeding,a maize intra-row weeding mechanism was designed in this study.The mechanism can detect maize seedlings by infrared beam tube,then a sliding-cutting bevel tool moves spirally amid maize seedlings,so as to eradicate intra-row weeds.A field experiment was conducted under the following experimental conditions:the bevel tool rotation speed was 800-1400 r/min,the mechanism forward speed was 4-7 km/h,and the bevel tool depth was 2-14 cm,the experimental results illustrated that the mechanism’s average weeding rate and seedling damage rate were 95.8%and 0.6%,respectively.The variance analysis showed that the primary and secondary factors that affecting the weeding rate and seedling damage rate were the same,which were bevel tool rotation speed,mechanism forward speed,bevel tool depth in soil in a descending order according to the significances.The result of the field experiment may provide a reference for intra-row weeding device design.展开更多
Public urban greenery greatly contributes to the residential and tourist value of cities in the Gulf Region,but due to the hyper-arid climatic conditions,the cost of irrigation and plant maintenance is very high.Exist...Public urban greenery greatly contributes to the residential and tourist value of cities in the Gulf Region,but due to the hyper-arid climatic conditions,the cost of irrigation and plant maintenance is very high.Existing strategies to reduce the monetary and ecological costs involve the cultivation of native xerophytic plantations,and/or the use of soil improvers to increase water-and nutrient-holding capacity of the sandy soils.Various soil improvers based on mineral,organic,or synthetic materials have entered the United Arab Emirates(UAE)market in recent years,but there is considerable uncertainty about how they should best be used in combination with ornamental plant stands involving xerophytic native plants.The present study investigated the effect of soil amendment and deep pipe irrigation on perennial ornamental plant stands involving native plants(Tephrosia appolinea(Gel.)Link in combination with Aerva javanica(Burm.f.)Juss.ex Schult.)and native-exotic plants(T.appolinea in combination with Ruelia simplex C.Wright)either or not topsoil and subsoil amendment with bentonite and hydrophobic sand under the irrigation water supply of less than 50%of reference evapotranspiration(ET0).After one year of cultivation,T.appolinea and A.javanica(native vs.native)produced high biomass and exhibited high water use efficiency(WUE)as compared with T.appolinea and R.simplex(native vs.exotic)combination given that no significant differences were found under the soil amendment treatments.All stands thrived under irrigation water supply far below what is usually supplied to exotic ornamental stands in public parks of the Al Ain City,the UAE.However,subsoil amendment in combination with deep pipe irrigation reduced the occurrence of weeds and increased the overall plant rooting depth.Our results suggest that subsoil amendment and irrigation up to 60-80 cm depth can potentially control ephemeral weed infestation,which is a great challenge in various plant production systems of the Gulf Region.The results of the present study suggest that the impact of soil amendment on the WUE of exotic plants is marginal and might not be economically justified.Replacing exotic with native ornamental plant species seems to have a far greater water-saving potential than the amendment of the soil,while weeds can be suppressed in the absence of topsoil moisture.展开更多
Agriculture plays a crucial role in the economy,and there is an increasing global emphasis on automating agri-cultural processes.With the tremendous increase in population,the demand for food and employment has also i...Agriculture plays a crucial role in the economy,and there is an increasing global emphasis on automating agri-cultural processes.With the tremendous increase in population,the demand for food and employment has also increased significantly.Agricultural methods traditionally used to meet these requirements are no longer ade-quate,requiring solutions to issues such as excessive herbicide use and the use of chemical fertilizers.Integration of technologies such as the Internet of Things,wireless communication,machine learning,artificial intelligence(AI),and deep learning shows promise in addressing these challenges.However,there is a lack of comprehensive documentation on the application and potential of AI in improving agricultural input efficiency.To address this gap,a desk research approach was used by utilizing peer-reviewed electronic databases like PubMed,Scopus,Goo-gle Scholar,Web of Science,and Science Direct for relevant articles.Out of 327 initially identified articles,180 were deemed pertinent,focusing primarily on AI’s potential in enhancing yield through better management of nutrients,water,and weeds.Taking into account researchfindings worldwide,we found that AI technologies could assist farmers by providing recommendations on the optimal nutrients to enhance soil quality and deter-mine the best time for irrigation or herbicide application.The present status of AI-driven automation in agricul-ture holds significant promise for optimizing agricultural input utilization and reducing resource waste,particularly in the context of three pillars of crop management,i.e.,nutrient,irrigation,and weed management.展开更多
Based on different types of diseases,pests and weeds in the whole growth period of rhubarb(sowing period-harvesting period),the corresponding green prevention and control technology is proposed,aiming to further reduc...Based on different types of diseases,pests and weeds in the whole growth period of rhubarb(sowing period-harvesting period),the corresponding green prevention and control technology is proposed,aiming to further reduce the application amount of pesticides and fertilizers in the production of medicinal sources of Lixian rhubarb during the"14 th Five-Year Plan"period.The results will provide a theoretical basis for increasing the promotion and application of agricultural prevention and control(including disease-resistant varieties,ecological regulation),physical prevention and control,biological prevention and control measures,thus ensuring effective protection of the ecological environment,green,healthy and sustainable development of traditional Chinese medicine agriculture in Longnan,and source quality of authentic medicinal materials.展开更多
The impulse to remain profitable by increasing agricultural production levels in view of the greater demand for food, provided impetus to production intensification. The aim of this review is to summarise current lite...The impulse to remain profitable by increasing agricultural production levels in view of the greater demand for food, provided impetus to production intensification. The aim of this review is to summarise current literature, reporting specifically on the impact of production intensification on habitats and yield constraints caused by weeds. Secondly, in alleviating these effects over the short term, ecological measures that enhance species diversity in conserved habitats and promote semi-natural habitats in the agricultural landscape, are discussed. In large-scale intensive agriculture, weed control is predominantly rooted in agrochemical applications in the form of herbicides. Long lasting intensive agricultural practices show discord both with the promotion of the biodiversity of microbes belowground and aboveground and with organisms involved in the breaking down of plant material. The presence of native species in the surroundings, in combination with hedgerows and field margins, with a comparatively intricate and balanced variety of plants in a sheltered environment, are essential for settlement of benign insects, particularly in the face of intensive agricultural production. The promising tactic of advantageous seed predators enables decreased herbicide applications. Crop mosaics arranged to advance compatibility at the landscape scale are important to bolster pollination services and insect management, while ecological variety in the surroundings acts as a safety net for habitat diversity. Weed control in combination with different tactics of vegetation use, comprising cover cropping, hedgerows and field margins, sets up safe havens in the landscape, and improves the diffusion of complementary life forms. Field margins perform a meaningful natural function as point of provision for forage, safe havens and distribution passageways for pollinators and insect predators. Production practices that promote more heterogeneity and combine high density semi-natural safe havens and habitat conservation in agro ecosystems are beneficial to species diversity across trophic levels and contribute to agricultural production stability and food safety.展开更多
China takes a tough stand on bribery and corruption of officials The Communist Party of China’s (CPC) Central Commission for Discipline Inspection (CCDI) had a busy year in 2009 as it worked to fight corruption. ...China takes a tough stand on bribery and corruption of officials The Communist Party of China’s (CPC) Central Commission for Discipline Inspection (CCDI) had a busy year in 2009 as it worked to fight corruption. At CCDI’s annual work review press conference on January 7, Deputy Secretary Gan Yisheng recited a list展开更多
In Bangladesh, the use of machinery in agriculture production is fast rising. Researchers are developing technology to replace traditional hand weeding to manage weeds in rice fields. The present study has been taken ...In Bangladesh, the use of machinery in agriculture production is fast rising. Researchers are developing technology to replace traditional hand weeding to manage weeds in rice fields. The present study has been taken to increase weeding efficiency and reduce the drudgery in weeding and mulching. A line-to-line distance of 20 cm, the operation is push-pull, and field operating condition at 2 - 4 cm standing water (for softening the field) was the designed hypothesis. The weeder consists of a skid/float, float holder, float adjuster, main body frame, rotor, axel, bush, rotor holder, rotor holder adjuster, handle, handle griper, handle holder, handle height adjuster, nut, bolt, etc. The designed weeder was fabricated using MS sheet, MS pipe, MS flat bar, MS nut-bolt, etc. When the rotors perform back and forth, the weeder’s two conical rotors with six plain blades and six serrated blades work together to uproot and bury the weeds. It also contains a 2 mm thick float assembly with a precise angle of 22 degrees. Weeds are uprooted by the weeder’s blades and buried in the muddy soil. It causes topsoil disturbance and enhances aeration. The weeding efficiency and capacity of the conical weeder were 81.92% and 0.0203 ha/h respectively. With a push-pull operation, the weeder can uproot and bury the weeds in a single row at a time. The pushing force and weight of weeder were 43.42 N and 5.6 kg respectively. Farmers can use this weeder to increase their comfort and reduce the drudgery associated with weeding and mulching in their fields.展开更多
Presently,precision agriculture processes like plant disease,crop yield prediction,species recognition,weed detection,and irrigation can be accom-plished by the use of computer vision(CV)approaches.Weed plays a vital ...Presently,precision agriculture processes like plant disease,crop yield prediction,species recognition,weed detection,and irrigation can be accom-plished by the use of computer vision(CV)approaches.Weed plays a vital role in influencing crop productivity.The wastage and pollution of farmland's natural atmosphere instigated by full coverage chemical herbicide spraying are increased.Since the proper identification of weeds from crops helps to reduce the usage of herbicide and improve productivity,this study presents a novel computer vision and deep learning based weed detection and classification(CVDL-WDC)model for precision agriculture.The proposed CVDL-WDC technique intends to prop-erly discriminate the plants as well as weeds.The proposed CVDL-WDC technique involves two processes namely multiscale Faster RCNN based object detection and optimal extreme learning machine(ELM)based weed classification.The parameters of the ELM model are optimally adjusted by the use of farmland fertility optimization(FFO)algorithm.A comprehensive simulation analysis of the CVDL-WDC technique against benchmark dataset reported the enhanced out-comes over its recent approaches interms of several measures.展开更多
Fagopyrum esculentum Moench (buckwheat) is a dicot species from the Polygonaceae family used as a cover crop in agricultural systems featured with a remarkable allelopathic potential for weed control, helping herbicid...Fagopyrum esculentum Moench (buckwheat) is a dicot species from the Polygonaceae family used as a cover crop in agricultural systems featured with a remarkable allelopathic potential for weed control, helping herbicide-resistance management and promoting substantial reductions in herbicide applications. The aim of this research was to examine the allelopathic potential of aqueous extracts from seeds and aerial part of buckwheat on seed germination and initial development of Bidens pilosa and Euphorbia heterophylla. Bioassay experiments were conducted under a completely randomized experimental design with four replications, containing 50 seeds each. Both weed seed species were harvested in a soybean field, and seed viability was previously assessed. Seeds were exposed to four concentrations (0, 25, 50, and 100%) from extracts of seeds (ES) and aerial part (EAP) of buckwheat. Germination speed index (GSI) in B. pilosa and E. heterophylla was daily evaluated throughout 14 and 16 days, respectively, whereas percentage of germination, abnormal seedlings, as well as non-germinated seeds, root (RL) and aerial part length (APL), and total dry matter (TDM) were rated at final germination test. EAP reduced the GSI, especially under the 100% concentration. Germination percentage was lower and abnormal seedlings increased for both weed species when seeds were exposed to EAP concentrations greater than 25%. However, ES did not impinge upon E. heterophylla germination. EAP and ES reduced the APL, RL, and TDM for concentrations greater than 50%, except for ES which did not affect E. heterophylla development. Both extracts from buckwheat have a high capacity to inhibit germination and compromise seedling development, culminating in such a potential alternative for B. pilosa and E. heterophylla management in agricultural systems.展开更多
Background The critical period of weed control(CPWC) refers to the period of time during the crop growth cycle when weeds must be controlled to prevent yield losses.Ultra-narrow row(UNR) is a method of planting of cot...Background The critical period of weed control(CPWC) refers to the period of time during the crop growth cycle when weeds must be controlled to prevent yield losses.Ultra-narrow row(UNR) is a method of planting of cotton in rows that are 25 cm or less apart.Amongst cultural techniques for weed control,the use of narrow row spacing is considered to be a most promising approach that can effectively suppress weed growth and provide greater yields in cotton.This cultivation system can shorten the length of the critical weed-crop interference duration and results in greater yield.The current research aimed to determination of critical time of weed control in cotton(Gossypium hirsutum L.) under conventional and ultra-narrow row spacing conditions.Field experiments were arranged as factorial experiment in a randomized complete block design with three replications.Factors were cultivation system(conventional(50 cm row spacing) and ultra narrow row(25 cm row spacing and weed treatment including 30,45,60,and 75 days weeding after emergence during the growing season(weed free),and 30,45,60,and 75 without weeding(weed infested) in the growing season along with weedy and weed-free from sowing to harvesting.A four-parameter loglogistic model was fit to the two sets of relating relative crop yield to data obtained from increasing durations of weed interference and lengths of weed-free period.Results In both years and cultivation systems,the relative yield of cotton decreased with the increasing duration of weed-interference but increased with the increasing duration of weed-free period.Ultra-narrow row cultivation delayed the beginning of the CPWC in cotton.Under ultra-narrow row condition,the CPWC ranged from 21 to 99 days after germination in 2021 and 23 to 91 days in 2022 based on the 5% acceptable yield loss.Under conventional cultivation CPWC ranged from 17 to 102 days after emergence in 2021 and 18 to 95 days after emergence in 2022.Conclusions Under both conventional and Ultra-narrow row conditions,weed interference reduces seed yield.Under ultra-narrow row condition,weed interference until 21.1–23.5 days after cotton emergence and under conventional condition,weed interference until 16.9–18.5 days after cotton emergence had not significant reduction on cotton yield.展开更多
Transgene escape could lead to genetically modified rice establishing wild populations in the natural environment and competing for survival space with weeds.However,whether the expression of the Bacillus thuringiensi...Transgene escape could lead to genetically modified rice establishing wild populations in the natural environment and competing for survival space with weeds.However,whether the expression of the Bacillus thuringiensis(Bt)gene in rice will alter the relationship between transgene plants and weeds and induce undesirable environmental consequences are poorly understood.Thus,field experiments were conducted to investigate the weed competitiveness and assess the ecological risk of transgenic Bt rice under herbicide-free and lepidopterous pest-controlled environments.Results showed that weed–rice competition in the direct-sowing(DS)field was earlier and more severe than that in the transplanting(TP)field,which resulted in a significant decrease in biomass and yield in DS.However,conventional Bt and non-Bt rice yield was not significantly different.The weed number,weed coverage ratio,and weed diversity of conventional Bt rice were significantly higher than those of non-Bt rice at the early growth and mature stages,especially in DS plots,suggesting that Bt traits did not increase the weed competitiveness of transgenic rice and had no negative effect on weed diversity.Grain yield and weed number varied between different hybrid rice lines,but those differences were insignificant between Bt and non-Bt rice.The number of insects increased with the increase of weeds in hybrid rice plots,whereas the insect number and diversity did not display a significant difference between Bt and non-Bt rice.Therefore,the ecological risk of transgenic Bt rice is comparable to non-Bt rice.展开更多
文摘I developed a weeding-duration model for Sakhalin fir （Abies sachalinensis （Fr. Schmidt） Masters） plantations that employs a generalized linear model. The number of years following planting that weeding is necessary is the response variable, and elevation, slope steepness, maximum snow depth, annual precipitation, geology, soil, site index, slope aspect, and vegetation type are explanatory variables. Among the explanatory variables, geology, soil, slope aspect, and vegetation type are categorical data. A Poisson distribution is assumed for the response variable, with a log-link function. Elevation, slope steepness, maximum snow depth, annual precipitation, site index, and vegetation type had a significant effect on weeding duration. Among the eight models with the smallest Akaike information criterion （AIC）, I chose the model with no multicollinearity among the explanatory variables. The weeding-duration model includes site index, maximum snow depth, slope steepness （angle） and vegetation type as explanatory variables; elevation and annual precipitation were not included in the selected model because of multicollinearity with maximum snow depth. This model is useful for cost-benefit analyses of afforestation or reforestation with Abies sachalinensis.
文摘This study quantified the effect of weeding frequency and weeding schedules on weeding operation time in a sugi(Cryptomeria japonica)plantation stand.A weeding operation time estimation model was developed;then the cumulative weeding operation time after six growing seasons was simulated using the developed model.The developed model included weed height,relative height of weeds to sugi,and initial planting density.The simulated cumulative weeding operation time decreased approximately 6%for each one-treatment decrease in weeding frequency.Under a three-treatment weeding frequency scenario,the simulated cumulative operation time when weeding was conducted during non-consecutive years was longer than that when weeding was conducted during three consecutive years.The results suggest that carrying out weeding treatment during consecutive years is the more effective for reduction of weeding costs.We conclude that weeding schedule as well as weeding frequency must be considered for reduction of weeding operation time.
文摘The System of Rice Intensification (SRI) has been attributed to improvement in rice production with various attributes being accrued from application of the SRI Principles. The most notable are savings on water use and increase in yield. Alternate Wetting and Drying (AWD) has also paved way for mechanical weed control in paddy fields. One of the major constraints to adoption of SRI is the perceived increased labour input due to the careful transplanting and frequent weed control. This paper evaluates the effect of mechanization on labour input in SRI in comparison to the less mechanized farmer practice. In attempt to reduce drudgery in transplanting under SRI, the drum seeder was used to establish the rice crop by direct seeding. This was then followed by using SRI practices i.e. AWD and mechanical weeding. Direct seeding using a drum seeder was compared to transplanting in both SRI and the common farmer practice. Hand weeding was also evaluated and compared to mechanical weeding. Labour input cost was also compared to the income accrued from the yields. From the study, it was noted that direct seeding using the drum seeder reduced labour input by 97% compared to transplanting. This was possible in that in direct seeding, and there was no nursery preparation and management as in transplanting. The use of a mechanical weeder reduced labour input by 28.3% in relation to hand weeding. Labour input cost for SRI was cheaper (Kshs. 124,080 per hectare) compared to the common farmer practice (Kshs. 139,117.50 per hectare). There was more yield from the SRI practice (2.75 Ton/ha) compared to the common farmer practice (1.88 Ton/ha).
文摘The experiment was conducted at agronomy farm of Sher-e-Bangla Agricultural University, Dhaka <span style="font-family:Verdana;">from</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> November 2017 to April 2018 to investigate the influence of weeding regimes on the performance of white maize varieties. The experiment comprised two varieties </span><i><span style="font-family:Verdana;">viz</span></i><span style="font-family:Verdana;">. YANGNUO-3000 and PSC-121, designated as V</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> and V</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> respectively combined with four weed control treatments </span><i><span style="font-family:Verdana;">viz.</span></i><span style="font-family:Verdana;"> T</span><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;"> = No weeding, T</span><sub><span style="font-family:Verdana;">1</span></sub></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">= One hand weeding at 60 DAS</span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">(days after sowing), T</span><sub><span style="font-family:Verdana;">2</span></sub></span><span style="font-family:;" "=""> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">= two hand weeding at 40 DAS and 60 DAS and T</span><sub><span style="font-family:Verdana;">3</span></sub></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">= Weed free after 40 DAS. The experiment was laid out in RCBD (factorial) with three replications. PSC-121 showed the superior performance in terms of plant height, leaf number plant</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, number of grains cob</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> (468.75), 100 grains weight (35.0837 g), grain yield (8.28 t ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">), stover yield (6.56 t ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) and harvest index (55.58%) over YANGNUO-3000. In </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">case of weed control treatments, the highest plant height, leaf number plant</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, number of grains cob</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;"> (464.54), 100 grains weight (37 g), grain yield (9.25 t ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">) and stover yield (7.46 t ha</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:;" "=""><span style="font-family:Verdana;">) were reported from T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">. All the parameters studied were found lowest with T</span><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;">. However, in terms of interaction, no single interaction was superior </span></span><span style="font-family:Verdana;">to</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> other alternatives. But in most of the cases V</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed the highest values regarding the maximum plant height, leaf number plant</span></span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">, number of grains cob</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:;" "=""><span style="font-family:Verdana;"> (494.97) and 100 grains weight (38 g). V</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed the highest grain yield (9.33 t ha</span></span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:;" "=""><span style="font-family:Verdana;">), whereas, V</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">T</span><sub><span style="font-family:Verdana;">0</span></sub><span style="font-family:Verdana;"> showed the lowest grain yield (5.49 t ha</span></span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">). The lowest weed density and weed biomass (12.17 no. m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:Verdana;"> and 4.33 g·m</span><sup><span style="font-family:Verdana;">-2</span></sup><span style="font-family:;" "=""><span style="font-family:Verdana;">) was recorded from T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">. The highest weed control efficiency (94.38%) was also recorded from T</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">. In </span></span><span style="font-family:Verdana;">the </span><span style="font-family:;" "=""><span style="font-family:Verdana;">case of variety V</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> showed better performance in terms of weed density, weed biomass and WCE (46.32%).</span></span>
基金Supported by National Science and Technology Support Program(2007BAD89B14)Special Fund for Agro-scientific Research in the PublicInterest(00803028)+3 种基金Major Technical Research Project of Ministry of Agriculture for Agricultural Structure Adjustment(06-03-07B)Project ofGuangdong Provincial Finance Department(YCY[2005]No.11,YCJ[2006]No.187)Agricultural Research Project of Guangdong ProvincialScience and Technology Department(2005B20101001)Special Fund forAgro-scientific Research in the Public Interest(201103001)
文摘Chemical weeding in dry direct seeding fields of single cropping middle-late rice was studied in Huida vegetable farm of Huizhou City in 2012. The main treatment was herbicide（ pretilachlor ＋ bensulfuron-methyl,Yangguo and butachlor）,and the sub-treatment was application method（ soil treatments,seedling treatment and integrated treatment）. The results showed that 80 g pretilachlor ＋ bensulfuron-methyl（ 36% pretilachlor ＋ 4% bensulfuron-methyl） diluted with 50 kg water could be sprayed or 200 g Yangguo（ 23. 9% butachlor ＋ 1. 1% bensulfuron-methyl） mixed with 15 kg sandy soil could be broadcasted per 667 m2 on the sowing day or the second day under moist condition of soil,which could effectively control weeds in dry direct seeding fields of single cropping middle-late rice.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(20120304201)Hebei Province Key Technology Research and Development Program(09250307D)~~
文摘According to experiments in many years in Hebei Province, the research explored weed comprehensive control technology on millet fields in terms of application range, prevention rules, prevention object, agricultural control, physical control, and chemical control and proposed specific methods and technological indices in order to provide technological references for comprehensive control on weeds of millet fields.
文摘[Objective] The paper was to explore weed control measures in tobacco fields in Anshun City. [Method] Different treatments on weed control were conducted in tobacco fields in Anshun City, Guizhou Province, from 2017 to 2019. [Result] Various treatments had no negative effect on tobacco plant growth in the field, and had different degrees of control effects on five dominant weeds, including Digitaria sanguinalis, Setaria viridis, Fagopyrum dibotrys, Commelina communis and Chenopodium album. White mulching film and 50% butralin·clomazone EC 160 m L/667 m^(2) + white mulching film had the worst performance, which had extremely significant or significant differences with other treatments. There was no sig-nificant difference among most treatments, and the overall effects were comprehensive(multi-factor) treatment > double factor treatment > single factor treatment. [Conclusion] Combination control is recommended in practical tobacco production.
文摘It is well known that quackgrass is both very aggressive and persistent. In agriculture, many attempts have been made to eliminate this weed without success. Within the context of a sustainable agriculture, mechanical control of quackgrass represents an interesting alternative to chemical means. The use of a ＂C＂ shaped mounted tine cultivator, a rotary cross-harrow, and an ＂S＂ shaped trailed tine cultivator （alone or in combination） to control quackgrass in grassland was investigated. The rate of quackgrass present in each experimental plot was determined before and after the treatments using a one square meter quadrant. Also, the time required for each passage as well as the fuel consumption were computed. Results revealed that the fuel consumption and the time required by the ＂C＂ and ＂S＂ shaped tine cultivators to transport and expose the rhizomes to the sun on the soil surface highly depend on the quality of tillage during the first stubble passage. Also, subsequent tillage with the ＂C＂ shaped tine cultivator after a first passage with a rotary cross-harrow resulted in less fuel consumption and passage time. On the other hand, stubble and subsequent soil tillage with only the ＂C＂ shaped tine cultivator is the least successful method.
基金The project was supported by the National Natural Science Foundation of China(Grant No.51475002)the Major Science and Technology projects of Anhui Province(Grant No.17030701046)the Natural Science Foundation of Anhui Province(Grant No.2008085QE270,1808085QE171).
文摘Aiming to solve problems in organic rice weeding a type of post-seat weeding machine was designed for rice paddies.The differences in the strengths and lengths of the root systems between the rice seedlings and the weeds were studied,and the motion track of the weeding wheel was analyzed to obtain the structural parameters of the weeding wheel.Then,the structural model of the weeding wheel was designed.The interaction process between the weeding wheel and soil in the paddy fields was simulated and analyzed based on the discrete element method,so as to investigate the working resistance change tendency of the weeding wheel and the orderliness of the soil disturbances.An orthogonal test was designed in this study,with three factors:the hoeing depth,the rotation rate of the weeding wheel,and the forward speed of the device.The influences of different operation parameters of the weeding machine on the weeding torque and soil disturbance speed were obtained based on a variance analysis of the test results.A multi-index comprehensive weighted scoring method was used to evaluate the simulation results.A soil bin test was conducted to verify the simulation results.Field experiments were carried out to test the working performance of the weeding machine.The comprehensive scoring results indicated that a better working performance of the weeding operation could be obtained when the hoeing depth was 50 mm,the rotation rate of the weeding wheel was 240 r/min,and the forward speed was 0.6 m/s.The results of the soil bin test were consistent with the simulation results.The results of the field experiment revealed that the weeding machine met the requirements for organic rice weeding.These results can provide a reference for the design of weeding machines for paddy fields.
基金supported by the National Natural Science Foundation of China(Grant No.31901408).
文摘Mechanical weeding not only avoids crop herbicide residue but also protects the ecological environment.Compared with mechanical inter-row weeding,mechanical intra-row weeding needs to avoid crop plants,which is conducive to causing a higher rate of seedling damage.In order to realize maize(Zea mays L.)intra-row weeding,a maize intra-row weeding mechanism was designed in this study.The mechanism can detect maize seedlings by infrared beam tube,then a sliding-cutting bevel tool moves spirally amid maize seedlings,so as to eradicate intra-row weeds.A field experiment was conducted under the following experimental conditions:the bevel tool rotation speed was 800-1400 r/min,the mechanism forward speed was 4-7 km/h,and the bevel tool depth was 2-14 cm,the experimental results illustrated that the mechanism’s average weeding rate and seedling damage rate were 95.8%and 0.6%,respectively.The variance analysis showed that the primary and secondary factors that affecting the weeding rate and seedling damage rate were the same,which were bevel tool rotation speed,mechanism forward speed,bevel tool depth in soil in a descending order according to the significances.The result of the field experiment may provide a reference for intra-row weeding device design.
基金partly funded by the Al Ain MunicipalityNational Water and Energy Center, United Arab Emirates University。
文摘Public urban greenery greatly contributes to the residential and tourist value of cities in the Gulf Region,but due to the hyper-arid climatic conditions,the cost of irrigation and plant maintenance is very high.Existing strategies to reduce the monetary and ecological costs involve the cultivation of native xerophytic plantations,and/or the use of soil improvers to increase water-and nutrient-holding capacity of the sandy soils.Various soil improvers based on mineral,organic,or synthetic materials have entered the United Arab Emirates(UAE)market in recent years,but there is considerable uncertainty about how they should best be used in combination with ornamental plant stands involving xerophytic native plants.The present study investigated the effect of soil amendment and deep pipe irrigation on perennial ornamental plant stands involving native plants(Tephrosia appolinea(Gel.)Link in combination with Aerva javanica(Burm.f.)Juss.ex Schult.)and native-exotic plants(T.appolinea in combination with Ruelia simplex C.Wright)either or not topsoil and subsoil amendment with bentonite and hydrophobic sand under the irrigation water supply of less than 50%of reference evapotranspiration(ET0).After one year of cultivation,T.appolinea and A.javanica(native vs.native)produced high biomass and exhibited high water use efficiency(WUE)as compared with T.appolinea and R.simplex(native vs.exotic)combination given that no significant differences were found under the soil amendment treatments.All stands thrived under irrigation water supply far below what is usually supplied to exotic ornamental stands in public parks of the Al Ain City,the UAE.However,subsoil amendment in combination with deep pipe irrigation reduced the occurrence of weeds and increased the overall plant rooting depth.Our results suggest that subsoil amendment and irrigation up to 60-80 cm depth can potentially control ephemeral weed infestation,which is a great challenge in various plant production systems of the Gulf Region.The results of the present study suggest that the impact of soil amendment on the WUE of exotic plants is marginal and might not be economically justified.Replacing exotic with native ornamental plant species seems to have a far greater water-saving potential than the amendment of the soil,while weeds can be suppressed in the absence of topsoil moisture.
文摘Agriculture plays a crucial role in the economy,and there is an increasing global emphasis on automating agri-cultural processes.With the tremendous increase in population,the demand for food and employment has also increased significantly.Agricultural methods traditionally used to meet these requirements are no longer ade-quate,requiring solutions to issues such as excessive herbicide use and the use of chemical fertilizers.Integration of technologies such as the Internet of Things,wireless communication,machine learning,artificial intelligence(AI),and deep learning shows promise in addressing these challenges.However,there is a lack of comprehensive documentation on the application and potential of AI in improving agricultural input efficiency.To address this gap,a desk research approach was used by utilizing peer-reviewed electronic databases like PubMed,Scopus,Goo-gle Scholar,Web of Science,and Science Direct for relevant articles.Out of 327 initially identified articles,180 were deemed pertinent,focusing primarily on AI’s potential in enhancing yield through better management of nutrients,water,and weeds.Taking into account researchfindings worldwide,we found that AI technologies could assist farmers by providing recommendations on the optimal nutrients to enhance soil quality and deter-mine the best time for irrigation or herbicide application.The present status of AI-driven automation in agricul-ture holds significant promise for optimizing agricultural input utilization and reducing resource waste,particularly in the context of three pillars of crop management,i.e.,nutrient,irrigation,and weed management.
基金Supported by Science and Technology Plan Promoting Regional Collaboration Project of Longnan City(2022-S.BF-01)Key Talent Project of Gansu Province(2021RCXM042,2020RCXM041).
文摘Based on different types of diseases,pests and weeds in the whole growth period of rhubarb(sowing period-harvesting period),the corresponding green prevention and control technology is proposed,aiming to further reduce the application amount of pesticides and fertilizers in the production of medicinal sources of Lixian rhubarb during the"14 th Five-Year Plan"period.The results will provide a theoretical basis for increasing the promotion and application of agricultural prevention and control(including disease-resistant varieties,ecological regulation),physical prevention and control,biological prevention and control measures,thus ensuring effective protection of the ecological environment,green,healthy and sustainable development of traditional Chinese medicine agriculture in Longnan,and source quality of authentic medicinal materials.
文摘The impulse to remain profitable by increasing agricultural production levels in view of the greater demand for food, provided impetus to production intensification. The aim of this review is to summarise current literature, reporting specifically on the impact of production intensification on habitats and yield constraints caused by weeds. Secondly, in alleviating these effects over the short term, ecological measures that enhance species diversity in conserved habitats and promote semi-natural habitats in the agricultural landscape, are discussed. In large-scale intensive agriculture, weed control is predominantly rooted in agrochemical applications in the form of herbicides. Long lasting intensive agricultural practices show discord both with the promotion of the biodiversity of microbes belowground and aboveground and with organisms involved in the breaking down of plant material. The presence of native species in the surroundings, in combination with hedgerows and field margins, with a comparatively intricate and balanced variety of plants in a sheltered environment, are essential for settlement of benign insects, particularly in the face of intensive agricultural production. The promising tactic of advantageous seed predators enables decreased herbicide applications. Crop mosaics arranged to advance compatibility at the landscape scale are important to bolster pollination services and insect management, while ecological variety in the surroundings acts as a safety net for habitat diversity. Weed control in combination with different tactics of vegetation use, comprising cover cropping, hedgerows and field margins, sets up safe havens in the landscape, and improves the diffusion of complementary life forms. Field margins perform a meaningful natural function as point of provision for forage, safe havens and distribution passageways for pollinators and insect predators. Production practices that promote more heterogeneity and combine high density semi-natural safe havens and habitat conservation in agro ecosystems are beneficial to species diversity across trophic levels and contribute to agricultural production stability and food safety.
文摘China takes a tough stand on bribery and corruption of officials The Communist Party of China’s (CPC) Central Commission for Discipline Inspection (CCDI) had a busy year in 2009 as it worked to fight corruption. At CCDI’s annual work review press conference on January 7, Deputy Secretary Gan Yisheng recited a list
文摘In Bangladesh, the use of machinery in agriculture production is fast rising. Researchers are developing technology to replace traditional hand weeding to manage weeds in rice fields. The present study has been taken to increase weeding efficiency and reduce the drudgery in weeding and mulching. A line-to-line distance of 20 cm, the operation is push-pull, and field operating condition at 2 - 4 cm standing water (for softening the field) was the designed hypothesis. The weeder consists of a skid/float, float holder, float adjuster, main body frame, rotor, axel, bush, rotor holder, rotor holder adjuster, handle, handle griper, handle holder, handle height adjuster, nut, bolt, etc. The designed weeder was fabricated using MS sheet, MS pipe, MS flat bar, MS nut-bolt, etc. When the rotors perform back and forth, the weeder’s two conical rotors with six plain blades and six serrated blades work together to uproot and bury the weeds. It also contains a 2 mm thick float assembly with a precise angle of 22 degrees. Weeds are uprooted by the weeder’s blades and buried in the muddy soil. It causes topsoil disturbance and enhances aeration. The weeding efficiency and capacity of the conical weeder were 81.92% and 0.0203 ha/h respectively. With a push-pull operation, the weeder can uproot and bury the weeds in a single row at a time. The pushing force and weight of weeder were 43.42 N and 5.6 kg respectively. Farmers can use this weeder to increase their comfort and reduce the drudgery associated with weeding and mulching in their fields.
文摘Presently,precision agriculture processes like plant disease,crop yield prediction,species recognition,weed detection,and irrigation can be accom-plished by the use of computer vision(CV)approaches.Weed plays a vital role in influencing crop productivity.The wastage and pollution of farmland's natural atmosphere instigated by full coverage chemical herbicide spraying are increased.Since the proper identification of weeds from crops helps to reduce the usage of herbicide and improve productivity,this study presents a novel computer vision and deep learning based weed detection and classification(CVDL-WDC)model for precision agriculture.The proposed CVDL-WDC technique intends to prop-erly discriminate the plants as well as weeds.The proposed CVDL-WDC technique involves two processes namely multiscale Faster RCNN based object detection and optimal extreme learning machine(ELM)based weed classification.The parameters of the ELM model are optimally adjusted by the use of farmland fertility optimization(FFO)algorithm.A comprehensive simulation analysis of the CVDL-WDC technique against benchmark dataset reported the enhanced out-comes over its recent approaches interms of several measures.
文摘Fagopyrum esculentum Moench (buckwheat) is a dicot species from the Polygonaceae family used as a cover crop in agricultural systems featured with a remarkable allelopathic potential for weed control, helping herbicide-resistance management and promoting substantial reductions in herbicide applications. The aim of this research was to examine the allelopathic potential of aqueous extracts from seeds and aerial part of buckwheat on seed germination and initial development of Bidens pilosa and Euphorbia heterophylla. Bioassay experiments were conducted under a completely randomized experimental design with four replications, containing 50 seeds each. Both weed seed species were harvested in a soybean field, and seed viability was previously assessed. Seeds were exposed to four concentrations (0, 25, 50, and 100%) from extracts of seeds (ES) and aerial part (EAP) of buckwheat. Germination speed index (GSI) in B. pilosa and E. heterophylla was daily evaluated throughout 14 and 16 days, respectively, whereas percentage of germination, abnormal seedlings, as well as non-germinated seeds, root (RL) and aerial part length (APL), and total dry matter (TDM) were rated at final germination test. EAP reduced the GSI, especially under the 100% concentration. Germination percentage was lower and abnormal seedlings increased for both weed species when seeds were exposed to EAP concentrations greater than 25%. However, ES did not impinge upon E. heterophylla germination. EAP and ES reduced the APL, RL, and TDM for concentrations greater than 50%, except for ES which did not affect E. heterophylla development. Both extracts from buckwheat have a high capacity to inhibit germination and compromise seedling development, culminating in such a potential alternative for B. pilosa and E. heterophylla management in agricultural systems.
文摘Background The critical period of weed control(CPWC) refers to the period of time during the crop growth cycle when weeds must be controlled to prevent yield losses.Ultra-narrow row(UNR) is a method of planting of cotton in rows that are 25 cm or less apart.Amongst cultural techniques for weed control,the use of narrow row spacing is considered to be a most promising approach that can effectively suppress weed growth and provide greater yields in cotton.This cultivation system can shorten the length of the critical weed-crop interference duration and results in greater yield.The current research aimed to determination of critical time of weed control in cotton(Gossypium hirsutum L.) under conventional and ultra-narrow row spacing conditions.Field experiments were arranged as factorial experiment in a randomized complete block design with three replications.Factors were cultivation system(conventional(50 cm row spacing) and ultra narrow row(25 cm row spacing and weed treatment including 30,45,60,and 75 days weeding after emergence during the growing season(weed free),and 30,45,60,and 75 without weeding(weed infested) in the growing season along with weedy and weed-free from sowing to harvesting.A four-parameter loglogistic model was fit to the two sets of relating relative crop yield to data obtained from increasing durations of weed interference and lengths of weed-free period.Results In both years and cultivation systems,the relative yield of cotton decreased with the increasing duration of weed-interference but increased with the increasing duration of weed-free period.Ultra-narrow row cultivation delayed the beginning of the CPWC in cotton.Under ultra-narrow row condition,the CPWC ranged from 21 to 99 days after germination in 2021 and 23 to 91 days in 2022 based on the 5% acceptable yield loss.Under conventional cultivation CPWC ranged from 17 to 102 days after emergence in 2021 and 18 to 95 days after emergence in 2022.Conclusions Under both conventional and Ultra-narrow row conditions,weed interference reduces seed yield.Under ultra-narrow row condition,weed interference until 21.1–23.5 days after cotton emergence and under conventional condition,weed interference until 16.9–18.5 days after cotton emergence had not significant reduction on cotton yield.
基金funded by the National Program of Transgenic Variety Development of China(2016ZX08001001)。
文摘Transgene escape could lead to genetically modified rice establishing wild populations in the natural environment and competing for survival space with weeds.However,whether the expression of the Bacillus thuringiensis(Bt)gene in rice will alter the relationship between transgene plants and weeds and induce undesirable environmental consequences are poorly understood.Thus,field experiments were conducted to investigate the weed competitiveness and assess the ecological risk of transgenic Bt rice under herbicide-free and lepidopterous pest-controlled environments.Results showed that weed–rice competition in the direct-sowing(DS)field was earlier and more severe than that in the transplanting(TP)field,which resulted in a significant decrease in biomass and yield in DS.However,conventional Bt and non-Bt rice yield was not significantly different.The weed number,weed coverage ratio,and weed diversity of conventional Bt rice were significantly higher than those of non-Bt rice at the early growth and mature stages,especially in DS plots,suggesting that Bt traits did not increase the weed competitiveness of transgenic rice and had no negative effect on weed diversity.Grain yield and weed number varied between different hybrid rice lines,but those differences were insignificant between Bt and non-Bt rice.The number of insects increased with the increase of weeds in hybrid rice plots,whereas the insect number and diversity did not display a significant difference between Bt and non-Bt rice.Therefore,the ecological risk of transgenic Bt rice is comparable to non-Bt rice.
