期刊文献+
共找到773篇文章
< 1 2 39 >
每页显示 20 50 100
Study on a Bowl-based Mechanism for Transplanting Potted Strawberry Seedlings
1
作者 Yin Da-qing Yang Yu-chao +2 位作者 Zhou Mai-le Wei Ming-xu Wang Jin-wu 《Journal of Northeast Agricultural University(English Edition)》 CAS 2023年第1期56-68,共13页
To improve the efficiency of fetching and transplanting seedlings for the mechanization of strawberry planting,an integrated transplanting mechanism was designed with protruding,fetching and planting performance to ac... To improve the efficiency of fetching and transplanting seedlings for the mechanization of strawberry planting,an integrated transplanting mechanism was designed with protruding,fetching and planting performance to achieve rapid fetching and pushing bowl movements.According to the working principle of the slewing mechanism,a kinematics model and the optimization goal were established,respectively.Based on visual auxiliary analysis software,optimal parameters were obtained.A three-dimensional model was established to obtain a simulation trajectory by means of a virtual simulation design analysis.Three-dimensional printing technology was used to manufacture the test prototype,and the actual working trajectories of the test prototype were extracted using high-speed photography technology,which verified the consistency of the actual trajectory with the theoretical and simulated trajectories.A prototype transplanting experiment was performed with the success rate of seedling extraction of 91.2%and excellent planting rate of 82.8%,which met the requirements for integrated strawberry harvesting,planting and transplanting.The experimental results verified the correctness and feasibility of the design of integrated transplanting mechanism. 展开更多
关键词 potted strawberry seedlings potted seedling transplanting integrated planting mechanism protruding and pushing bowl type parameter optimization
下载PDF
Design and Experimental Research on Seedling Pick-Up Mechanism of Planetary Gear Train with Combined Non-circular Gear Transmission 被引量:11
2
作者 Yaxin Yu Jikun Liu +4 位作者 Bingliang Ye Gaohong Yu Xuejun Jin Liang Sun Junhua Tong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第3期42-54,共13页
Currently, transplanting mechanisms for dryland plug seedlings in China are mainly semiautomatic and have low efficiency. The rotary seedling pick-up mechanism with a planetary gear train for non-uniform intermittent ... Currently, transplanting mechanisms for dryland plug seedlings in China are mainly semiautomatic and have low efficiency. The rotary seedling pick-up mechanism with a planetary gear train for non-uniform intermittent transmission, and a concave and convex locking arc device, has a large rigid impact. To solve these problems, according to the design requirements for a dryland plug seedling transplanting mechanism, a rotary seedling pick-up mechanism of a planetary gear train with combined non-circular gear transmission of incomplete eccentric circular and noncircular gears was proposed. This has the characteristics of two-times greater fluctuation of the transmission ratio in a cycle, and can achieve a non-uniform continuous drive. Through analysis of the working principle of the seedling pick-up mechanism, its kinematics model was established. The human–computer interaction optimization method and self-developed computer-aided analysis and optimization software were used to obtain a set of parameters that satisfy the operation requirements of the seedling pick-up mechanism. According to the optimized parameters, the structure of the seedling pick-up mechanism was designed, a virtual prototype of the mechanism was created, and a physical prototype was manufactured. A virtual motion simulation of the mechanism was performed, high-speed photographic kinematics tests were conducted, and the kinematic properties of the physical prototype were investigated, whereby the correctness of the theoretical model and the optimized design of the mechanism were verified. Further, laboratory seedling pick-up tests were conducted. The success ratio of seedling pick-up was 93.8% when the seedling pick-up efficiency of the mechanism was 60 plants per minute per row, indicating that the mechanism has a high efficiency and success ratio for seedling pick-up and can be applied to a dryland plug seedling transplanter. 展开更多
关键词 Dryland plug seedling transplanter Rotary seedling pick-up mechanism TRANSMISSION ratio Non-uniform continuous TRANSMISSION COMBINED NON-CIRCULAR gear TRANSMISSION Optimization design
下载PDF
Effects of site preparation methods on soil physical properties and outplanting success of coniferous seedlings in boreal forests
3
作者 Aleksey S.Ilintsev Elena N.Nakvasina Alexander P.Bogdanov 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期70-80,共11页
This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of forests.This study was conducted on 12 forest sites ... This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of forests.This study was conducted on 12 forest sites in taiga forests of the European part of Russia.A total of 54 plots were set up to assess seedling survival;root collar diameter,height,and heigh increment were measured for 240 seedlings to assess growth.In the rooting layer,240 soil samples were taken to determine physical properties.The study showed that soil treatment methods had no effect on bulk density and total porosity in Cladina sites.However,reduced soil moisture was noted,particularly in mounds,resulting in increased aeration.In Myrtillus sites,there were increased bulk density,reduced soil moisture,and total porosity in the mounds.Mounding treatment in Polytrichum sites resulted in reduced soil moisture and increased aeration porosity.In the Myrtillus and Polytrichum sites,patch scarification had no effects on physical properties.In Polytrichum sites,survival rates,heights,and heigh increments of bareroot Norway spruce seedlings in mounds were higher than in patches;however,the same did not apply to diameter.In Cladina and Myrtillus sites,there was no difference in growth for bareroot and containerised seedlings with different soil treatments.Growing conditions and soil types should be considered when applying different soil treatment methods to ensure high survival rates and successful seedling growth. 展开更多
关键词 Boreal forests mechanical site preparation Patch scarification MOUNDING Soil properties Containerised seedlings Bareroot seedlings
下载PDF
Design of Vegetable Pot Seedling Pick‑up Mechanism with Planetary Gear Train 被引量:8
4
作者 Zhipeng Tong Gaohong Yu +2 位作者 Xiong Zhao Pengfei Liu Bingliang Ye 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2020年第4期87-97,共11页
It has been challenging to design seedling pick-up mechanism based on given key points and trajectories,because it involves dimensional synthesis and rod length optimization.In this paper,the dimensional synthesis of ... It has been challenging to design seedling pick-up mechanism based on given key points and trajectories,because it involves dimensional synthesis and rod length optimization.In this paper,the dimensional synthesis of seedling pickup mechanism with planetary gear train was studied based on the data of given key points and the trajectory of the endpoint of seedling pick-up mechanism.Given the positions and orientations requirements of the five key points,the study first conducted a dimensional synthesis of the linkage size and center of rotation.The next steps were to select a reasonable solution and optimize the data values based on the ideal seedling trajectory.The link motion was driven by the planetary gear train of the two-stage gear.Four pitch curves of noncircular gears were obtained by calculating and distributing the transmission ratio according to the data.For the pitch curve with two convex points,the tooth profile design method of incomplete noncircular gear was applied.The seedling pick-up mechanism was tested by a virtual prototype and a physical prototype designed with the obtained parameter values.The results were consistent with the theoretical design requirements,confirming that the mechanism meets the expected requirements for picking seedlings up.This paper presents a new design method of vegetable pot seedling pick-up mechanism for an automatic vegetable transplanter. 展开更多
关键词 Combined incomplete noncircular gear mechanism dimension synthesis Planetary gear train seedling pick-up mechanism
下载PDF
Outdoor Domestication Cultivation and Survival Mechanism for Tissue Culture Seedlings of Paeonia suffruticosa
5
作者 Xianglong MA Jingxu WU +2 位作者 Yixin LIANG Shaohua LIU Yongmei WANG 《Asian Agricultural Research》 2019年第8期60-63,共4页
In order to reveal the differences between different peony varieties and facilities,thousands of tissue culture seedlings of 21 Itoh peony varieties imported from abroad were used as test materials,and the peony domes... In order to reveal the differences between different peony varieties and facilities,thousands of tissue culture seedlings of 21 Itoh peony varieties imported from abroad were used as test materials,and the peony domestication cultivation method used in the past was used as a control. The technical measures and mechanisms for the outdoor domestication of seedlings and the survival of field transplantation were studied. The results indicate that the main factors and measures for effectively protecting the outdoor transplanting of tissue culture seedlings include cultivating sound and strong seedlings,transplanting in proper period of spring,and providing good ventilating places and facilities,removing leaves,keeping buds and releasing dormancy before transplantation,planting depth should meet the requirement of exposing to the root neck,changing the pots according to the size of seedlings,the substrate should be loose and permeable,seriously disinfected and sterilized,scientific management,and prevention and control of diseases and insect pests. In addition,the survival mechanism was also analyzed,and the reasons and countermeasures for the successful application of peony tissue culture in China were found. Finally,the differences in survival rates between different varieties and facilities were summarized. 展开更多
关键词 Tissue culture seedlings of PAEONIA suffruticosa OUTDOOR DOMESTICATION CULTIVATION SURVIVAL rate SURVIVAL mechanism
下载PDF
Effects of Farming and Seedling-raising Methods on Population Growth and Grain Yield of Mechanized Transplanting Rice
6
作者 杨波 霍晓玲 +3 位作者 吴健英 杨文婷 肖启银 任万军 《Agricultural Science & Technology》 CAS 2017年第7期1235-1239,共5页
The effects of farming method, rice variety and seedling-raising method were studied on the population growth quality and grain yield of the mechanized transplanting rice by way of three-factor split plot design. The ... The effects of farming method, rice variety and seedling-raising method were studied on the population growth quality and grain yield of the mechanized transplanting rice by way of three-factor split plot design. The results showed that the no-tillage mechanical transplanting treatment was poorer than the conventional mechanical transplanting treatment in transplanting quality in general, but the former was similar to the latter in population growth quality. In regard to grain yield, the no-tillage mechanical transplanting treatment was lower than the conventional me- chanical transplanting treatment. Raising both pot-mat seedling and plastic-tray seedling did not make much difference in population growth and grain yield of mechanized transplanting rice, so both of the seedling-raising methods can be adopted according to practical conditions. 展开更多
关键词 RICE No-tillage mechanical transplanting seedling raising Population growth Grain yield
下载PDF
Effect of Seedling Raising Methods on Leaf Photosynthesis and Grain Yield of Mechanically-transplanted Japonica Rice
7
作者 赵轶鹏 王友霜 +5 位作者 吴玉玲 胡婷婷 王健康 丁成伟 郭荣良 徐家安 《Agricultural Science & Technology》 CAS 2017年第11期2057-2061,2063,共6页
This study was conducted to investigate the effects of seedling raising modes on photosynthetic charactedsticsand grain yield under wheat straw returning. Four representative cultivars in Huaibei area were selected as... This study was conducted to investigate the effects of seedling raising modes on photosynthetic charactedsticsand grain yield under wheat straw returning. Four representative cultivars in Huaibei area were selected as test materials. By setting potted seedlings and carpet seedlings, the effects of different nursery meth- ods on the photosynthesis of rice at different growth stages in Huaibei area were investigated. Compared with carpet seedlings, the leaf area index of potted seedlings decreased at the maturation stage, but the dry weight of leaf shewed no significant difference.The SPAD of potted seedlings had an increasing trend after transplanting, but the SPAD increased differently according to cultivars. The net photosynthetic rate, stomatal conductance and transpiration rate of the leaves of pot seeding rice were significantly higher than those of carpet seedling rice on the 85^th d after transplanting. However, theintracellular CO2 concentration and water use efficiency of leaves had no significant differences between different 'treatments. The results indicate that the photosynthetic capacity of flag leaves of pot seedling rice is stronger in early and middle stages, but the decay rate of photosynthetic function is slightly faster than carpet seedling rice, which might be the main reason for the rice yield of potted seedlings having no remarkable difference from carpet seedlings. 展开更多
关键词 seedling raising method mechanically transplanting Leaf photosynthesis Grain yield
下载PDF
Quick and Accurate Counting of Rapeseed Seedling with Improved YOLOv5s and Deep-Sort Method
8
作者 Chen Su Jie Hong +1 位作者 Jiang Wang Yang Yang 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第9期2611-2632,共22页
The statistics of the number of rapeseed seedlings are very important for breeders and planters to conduct seed quality testing,field crop management and yield estimation.Calculating the number of seedlings is ineffic... The statistics of the number of rapeseed seedlings are very important for breeders and planters to conduct seed quality testing,field crop management and yield estimation.Calculating the number of seedlings is inefficient and cumbersome in the traditional method.In this study,a method was proposed for efficient detection and calculation of rapeseed seedling number based on improved you only look once version 5(YOLOv5)to identify objects and deep-sort to perform object tracking for rapeseed seedling video.Coordinated attention(CA)mechanism was added to the trunk of the improved YOLOv5s,which made the model more effective in identifying shaded,dense and small rapeseed seedlings.Also,the use of the GSConv module replaced the standard convolution at the neck,reduced model parameters and enabled it better able to be equipped for mobile devices.The accuracy and recall rate of using improved YOLOv5s on the test set by 1.9%and 3.7%compared to 96.2%and 93.7%of YOLOv5s,respectively.The experimental results showed that the average error of monitoring the number of seedlings by unmanned aerial vehicles(UAV)video of rapeseed seedlings based on improved YOLOv5s combined with depth-sort method was 4.3%.The presented approach can realize rapid statistics of the number of rapeseed seedlings in the field based on UAV remote sensing,provide a reference for variety selection and precise management of rapeseed. 展开更多
关键词 Rapeseed seedling UAV improved YOLOv5s attention mechanism real-time detection
下载PDF
Design and experimental research on the sweet potato seedling transplanting mechanism of the planetary gear train with deformed elliptical gear transmission
9
作者 Bingliang Ye Yuxuan Ye +3 位作者 Haili Zhou Gaohong Yu Xiong Zhao Bin Deng 《International Journal of Agricultural and Biological Engineering》 SCIE 2024年第3期91-99,共9页
Aiming at the lack of suitable machines for sweet potato seedling transplanting in China,and according to the agronomic requirements for the horizontal insertion method of sweet potato seedling,a new sweet potato seed... Aiming at the lack of suitable machines for sweet potato seedling transplanting in China,and according to the agronomic requirements for the horizontal insertion method of sweet potato seedling,a new sweet potato seedling transplanting mechanism of planetary gear train was proposed based on the non-uniform transmission of deformed elliptical gear.The working principle of the transplanting mechanism was analyzed,and the kinematics modeling and analysis of the mechanism were carried out.The study established the numerical objectives of the transplanting mechanism and applied the theory of membership function to establish a mathematical model for the parameter-guided optimization design of the transplanting mechanism.The parameter-guided optimization design software was developed to obtain a set of optimal mechanism parameters that satisfied the motion trajectory of sweet potato transplanting and the posture of the transplanting arm.Based on the optimized parameters,the structure of the transplanting mechanism was designed,and a virtual prototype of the mechanism was created,whereby a virtual motion simulation of the transplanting mechanism was conducted to verify the correctness of the kinematics model and design of the mechanism.The high-speed photographic kinematics test of the mechanism prototype and sweet potato seedling transplanting tests were conducted to test the mechanism’s kinematic characteristics and transplanting performance.The test results show that the test trajectory of the mechanism and test posture of the transplanting arm are almost consistent with the theoretical and simulation trajectory,meeting the agronomic requirements of the horizontal insertion method of sweet potato seedling;And when the rotary speed of the mechanism are 20 r/min and 30 r/min,the average success ratios of sweet potato seedlings transplanting are 90%and 82%,respectively,which prove the application feasibility of the mechanism in the practical machines. 展开更多
关键词 sweet potato seedling transplanter transplanting mechanism deformed elliptical gear transmission kinematics analysis membership function optimization design
原文传递
Overlapped Tray Seedling Raising Model for Mechanical Transplanting of Rice
10
作者 Defeng ZHU Yuejun WANG +2 位作者 Huizhe CHEN Yicheng XU Yiping CHEN 《Asian Agricultural Research》 2019年第1期56-59,共4页
With the development of China's social economy,transfer of rural labors,and rise of labor costs,the rice production technologies are changing from manual operation to mechanical operation.The core of mechanical ri... With the development of China's social economy,transfer of rural labors,and rise of labor costs,the rice production technologies are changing from manual operation to mechanical operation.The core of mechanical rice production is mechanical planting,while the key to mechanical planting is the seedling raising.On the basis of analyzing and studying the problems and experience of traditional mechanical transplanting of rice,a new overlapped tray seedling raising model was introduced.Main features of this model: substrate seedling raising and overlapped seedling tray.The seedling trays for seeding line are overlapped,and the overlapped trays are moved into the seedling room with controlled temperature and humidity.The temperature of the seedling room is controlled at 30-32℃,and the humidity of the seedling room is controlled at above 90%.After about 48 h,when the seedling height reaches 0.5 cm,move the seedling trays to the nursery.This model consists of one seeding center( seedling raising center) and N nurseries,to realize 1 + N seedling raising for mechanical transplanting of rice.One seeding center can provide seedlings for several hundred to several thousand hectares of mechanical transplanting of rice,and provide a new model for social services.This model could improve the quality of seedlings,increase the seedling survival rate by about 20%,reduce the seedling raising costs by 15%-20%,reduce the seedling raising risks,and greatly increase the utilization rate of the site and equipment of seedling raising center. 展开更多
关键词 RICE mechanICAL TRANSPLANTING seedling RAISING Overlapped TRAY
下载PDF
Improvement of Pick-up Mechanism for Composite Particle Emissions
11
《Chinese journal of nuclear physics》 1996年第1期29-33,共5页
ImprovementofPick┐upMechanismforCompositeParticleEmisionsZhangJingshangandZhouSuijianChinaInstituteofAtomicE... ImprovementofPick┐upMechanismforCompositeParticleEmisionsZhangJingshangandZhouSuijianChinaInstituteofAtomicEnergy,P.O.Box275(... 展开更多
关键词 pick-up COMPOSITE EMISSIONS IMPROVEMENT mechanism
下载PDF
Reverse design and tests of vegetable plug seedling pick-up mechanism of planetary gear train with non-circular gears 被引量:3
12
作者 Zhifang Zhu Guohuan Wu +1 位作者 Bingliang Ye Yongchang Zhang 《International Journal of Agricultural and Biological Engineering》 SCIE 2023年第2期96-102,共7页
In the previous research,the seedling pick-up mechanism of the planetary gear train with incomplete eccentric circular gear and non-circular gears for vegetable plug seedlings still has two shortcomings.One is that no... In the previous research,the seedling pick-up mechanism of the planetary gear train with incomplete eccentric circular gear and non-circular gears for vegetable plug seedlings still has two shortcomings.One is that not enough seedling pick-up depth leads to a low success ratio of seedling pick-up at high rotation speeds,the other is that the smaller seedling pushing angle results in poor seedling pushing effect.Therefore,the reverse design of the seedling pick-up mechanism based on its motion trajectory was carried out.The local trajectory of seedling pick-up and seedling pushing sections was adjusted to obtain the theoretical motion trajectory of the seedling pick-up mechanism.The cubic non-uniform B-spline curve was used to fit the adjusted trajectory.A novel seedling pick-up mechanism of the planetary gear train with non-circular gears was proposed,including three combined non-circular gears,four non-circular gears,one planetary carrier,and two seedling pick-up arms.The reverse design model of the mechanism was established.The analysis and design software of the mechanism was developed to obtain the mechanism parameters meeting design requirements.The virtual prototype of the mechanism was established and its physical prototype was manufactured.Through the virtual motion simulation and high-speed photographic kinematics bench tests of the mechanism,the kinematic model and results of reverse design of the mechanism were verified,with the kinematic performances of the mechanism prototype studied.The seedling pick-up tests of the mechanism were conducted in the laboratory.The success ratios of seedling pick-up were 94.2%,95.6% and 90.2% while the seedling pick-up efficiencies of the mechanism were 60,80 and 100 plants per minute per row,respectively.Besides,the seedling pushing effect was improved mush because of the greater seedling pushing angle.The seedling pick-up mechanism through revise design is of high value to be applied in the practical vegetable plug seedling transplanters. 展开更多
关键词 vegetable plug seedling seedling pick-up mechanism non-circular gear reverse design virtual simulation seedling pick-up tests
原文传递
Effects of Seed Rate on Root Twining Power and Seedling Quality of Machine-transplanted Super Rice 被引量:3
13
作者 滕飞 朱德峰 +2 位作者 陈惠哲 蔡雪青 徐一成 《Agricultural Science & Technology》 CAS 2015年第12期2644-2648,2652,共6页
In order to investigate the effects of seed rate on root twining power and seedling quality of machine-transplanted super rice cultivars, Yongyou 12 and Zhongzheyou No.l, total 6 seed rates were arranged, and the grow... In order to investigate the effects of seed rate on root twining power and seedling quality of machine-transplanted super rice cultivars, Yongyou 12 and Zhongzheyou No.l, total 6 seed rates were arranged, and the growth characteris- tics, quality and root twining power of machine-transplanted rice seedlings were studied. The results showed that seed rate had great effects on root twining power and qualityof rice seedlings; with the increase of seed rate, the root twining power of rice seedlings was increased, but the quality of rice seedlings was significantly reduced; under the condition of high seed rate, rice seedlings were weak with less accumulate dry matter and nonuniform growth, and the proportion of weak seedlings was higher. When the seed rate of both rice cultivars was reduced by 10 g/tray, the average seedling height was increased by 0.5 cm, leaf age was increased by 0.1, stem base diameter was increased by 0.1 cm, and root number per plant was increased by 0.3. When the seed rate was increased by 10 g/tray, the accumulated dry matter per plant was reduced by 5.1 mg. With the increase of seed rate, the seedling quality of Zhongzheyou No.1 was decreased rapidly, and the proportion of weak seedlings was increased rapidly. However, Yongyou 12 has a larger elasticity in seed rate. When the seed rate reached to 50 g/tray, blanket seedlings of Yongy- ou 12 were nursed with uniform growth and higher quality, but the shoots were sparse with lower leaf area index. However, when the seed rate was up to 50 g/tray, blanket seedlings of Zhongzheyou No.1 were nursed with uniform growth and higher quality, as well as higher-density shoots. From a comprehensive point of view, the optimum seed rates of Yongyou 12 and Zhongzheyou No.1 were 65 and 50 g/tray, respectively. 展开更多
关键词 RICE Super rice mechanical transplanting Seed rate Blanket seedling seedling quality
下载PDF
Effects of soilless substrates on seedling quality and the growth of transplanted super japonica rice 被引量:11
14
作者 LEI Wu-sheng DING Yan-feng +2 位作者 LI Gang-hua TANG She WANG Shao-hua 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第5期1053-1063,共11页
This study was conducted to investigate the effects of soilless substrates of hydroponically grown long-mat seedlings (HLMS) on seedling quality and field growth characteristics of transplanted super japonica rice. ... This study was conducted to investigate the effects of soilless substrates of hydroponically grown long-mat seedlings (HLMS) on seedling quality and field growth characteristics of transplanted super japonica rice. A widely grown conventional super japonica rice cultivar (Wuyunjing 23) was selected as the test material. The effect of HLMS on seedling quality, mechanical transplantation quality, field growth characteristics, yield, and benefit-cost ratio were compared with seedlings grown in organic substrates and traditional nutritive soil, whJch was selected as the control. Root number, root twJstJng power and root activity of seedlings cultivated by HLMS were decreased compared to that of the organic substrates andcontrol. However, seedling root length as well as aboveground growth were increased compared to the organic substrates and control seed- lings. In the HLMS, the content of gibberellin acid (GA3) decreased while abscisic acid (ABA) content increased compared to that of the organic substrates and control seedlings. During the early stages after transplanting, the re-greening of HLMS was delayed compared to that of the organic substrates and control seedlings. Nevertheless, there were no significant differences in tiller dynamics and crop yield among the HLMS, organic substrates and control treatments. The effects of HLMS on seedling production were similar to those of the organic substrates and traditional nutritive soil in the present study, suggesting that HLMS have the potential to replace traditional nutritive soil in seedling production without decreasing crop yield. Finally, it is important to reduce organic substrates and topsoil dependence during rice seedling production and worthwhile to consider HLMS popularization and its application on a larger scale. 展开更多
关键词 super hybrid rice (Oryza sativa L.) mechanical transplantation seedling quality YIELD seedling raised method
下载PDF
Wheat genotypes tolerant to heat at seedling stage tend to be also tolerant at adult stage:The possibility of early selection for heat tolerance breeding 被引量:1
15
作者 Lu Lu Hui Liu +1 位作者 Yu Wu Guijun Yan 《The Crop Journal》 SCIE CSCD 2022年第4期1006-1013,共8页
Wheat production is seriously influenced by extreme hot weather,which has attracted increasing attention.It is important to compare wheat responses to heat at seedling and reproductive stages,to explore the potential ... Wheat production is seriously influenced by extreme hot weather,which has attracted increasing attention.It is important to compare wheat responses to heat at seedling and reproductive stages,to explore the potential relationship between the performances at different growing stages and the possibility of early selection to accelerate heat tolerance breeding.In this study,forty wheat genotypes were screened under heat stress at both seedling and adult stages.It was found that root lengths at seedling stage were severely reduced by heat stress with significant variations among wheat genotypes.Heat-tolerant genotypes at seedling stage showed less root length decrease than susceptible ones.Wheat genotypes tolerant at seedling stage showed higher yield at adult stage after heat treatment.The performances of wheat genotypes screened under heat stress at seedling and adult stages were ranked by seedling damage index and adult damage index.A significant positive relationship was found between heat tolerance at seedling stage and at adult stage(r=0.6930),suggesting a similar tolerant/susceptible mechanism at different plant growth stages and the possibility of early selection at seedling stage for breeding heat tolerance.Extremely tolerant and susceptible genotypes with consistent performances at seedling and adult stages were genetically compared and associated SNP markers and linked candidate genes were identified. 展开更多
关键词 Heat tolerance seedling stage Adult stage Linear regression Genetic mechanism
下载PDF
Effects of uniconazole rate on agronomic traits and physiological indexes of rapeseed blanket seedling 被引量:6
16
作者 Qingsong Zuo Long Wang +4 位作者 Jingdong Zheng Jingjing You Guang Yang Suohu Leng Jingyi Liu 《Oil Crop Science》 2020年第4期198-204,共7页
Mechanized transplanting of rapeseed(Brassica napus L.)blanket seedling is an innovative cultivation technology.Cultivating high quality blanket seedling to ensure high survival rate of seedling after transplanting is... Mechanized transplanting of rapeseed(Brassica napus L.)blanket seedling is an innovative cultivation technology.Cultivating high quality blanket seedling to ensure high survival rate of seedling after transplanting is the key of the technology.The effects of different uniconazole rates of 0,0.5,1.0,1.5 and 2.0 mg/tray,spraying at one leaf and one heart stage,on selected agronomic traits,physiological indexes and survival rate of two rapeseed cultivars(‘Qinyou 100 and’Yangyou 90)were investigated in 2018 and 2019.Our results showed that the plant height decreased significantly with the increase of uniconazole rate.However,the collar diameter increased significantly with the increase of uniconazole rate up to 1.5 mg/tray,and the leaf area,dry weights of root and shoot increased with increased uniconazole rate up to 1.0 mg/tray.The root to shoot ratios,N concentrations of root and shoot with the uniconazole rates of 1.0 and 1.5 mg/tray were higher than those with other treatments.As uniconazole rate increasing,gibberellin(GA)and auxin(IAA)concentrations of root and shoot decreased,while abscisic acid(ABA)concentrations increased,and cytokinin(CTK)concentrations topped at uniconazole rate of 1.0 mg/tray and decreased thereafter.The seedling survival rates with 1.0 and 1.5 mg/tray were greatly higher than those in other treatments.Regression analysis suggested plant survival rate was positively related to CTK concentrations and negatively to GA concentrations of root and shoot.To achieve high survival rate after mechanized transplanting,our study revealed that the uniconazole applied at a rate of 1.0 mg/tray was recommended as the best,followed by 1.5 mg/tray.The findings would help to enhance qualities of rapeseed blanket seedling and to promote popularization of mechanized transplanting of rapeseed production. 展开更多
关键词 Rapeseed blanket seedling mechanized transplanting Uniconazole rate Hormone concentration Survival rate
下载PDF
Impact of mechanical stimulation on the life cycle of horticultural plant 被引量:1
17
作者 Zhengguang Liu Tobi Fadiji +2 位作者 Jun Yang Zhiguo Li Fideline Tchuenbou-Magaia 《Horticultural Plant Journal》 SCIE CAS CSCD 2023年第3期381-394,共14页
Mechanical stimulation technology is critical in agricultural crop production because it is constantly regarded as a developing green technology to regulate plants to meet people's need for green and healthy agric... Mechanical stimulation technology is critical in agricultural crop production because it is constantly regarded as a developing green technology to regulate plants to meet people's need for green and healthy agricultural products. Various environmental mechanical stimulation impacts seed germination, seedling growth, flowering date, fruit quantity, and fruit quality throughout the life cycle of a horticultural plant. This study first outlines the basic characteristics of six types of common mechanical stimulation in nature:precipitation, wind, gravity,touch, sound, and vibration. The effects of various mechanical stimulation types on the seed, seedling, flowering, and fruit of horticultural plants throughout their whole life cycle are then presented, as reviewed in the recent 100 years of existing literature. Finally, potential future study directions are discussed. The main challenge in mechanical stimulation technology is to uncover its potential capabilities for regulating and controlling plant development and fruit quality in green agriculture instead of agricultural chemicals. 展开更多
关键词 mechanical stimulation PLANT SEED seedling FLOWERING FRUIT
下载PDF
番茄钵苗移栽探出式取钵机构设计与试验 被引量:3
18
作者 辛亮 王明成 +3 位作者 孙国玉 张浩 孙铭翼 王航 《农业机械学报》 EI CAS CSCD 北大核心 2024年第3期96-105,共10页
为了降低番茄钵苗移栽过程取钵机构对秧苗钵土根系的损伤,同时避免机械式钵苗移栽机构设计特殊取苗轨迹与姿态的优化难题,提出了一种可与系列移栽机构配合使用的番茄钵苗探出式取钵机构,实现取苗各关键位置机构秧针以固定角度完成探出... 为了降低番茄钵苗移栽过程取钵机构对秧苗钵土根系的损伤,同时避免机械式钵苗移栽机构设计特殊取苗轨迹与姿态的优化难题,提出了一种可与系列移栽机构配合使用的番茄钵苗探出式取钵机构,实现取苗各关键位置机构秧针以固定角度完成探出入钵、移动送苗及收回推秧工序。根据钵苗移栽取钵过程分析与设计要求,建立了探出式取钵机构力学分析模型,并获得影响秧针扎入钵土时驱动杆受最小驱动力的因素。基于Matlab App Designer平台开发了取钵机构计算机辅助分析设计软件,获得满足番茄钵苗移栽要求的取钵机构设计参数集。采用三因素五水平二次回归正交旋转中心组合试验方法,以驱动杆斜杆夹角、钵体含水率、入钵深度为试验因素,以钵体完整率和取苗成功率为评价指标,试制样机并搭建台架实施参数组合优化及验证试验,结果表明:探出式取钵机构可有效地配合取苗机构完成各项性能工作要求,在参数组合为驱动斜杆间夹角112°、钵体含水率57.5%、入钵深度28.4 mm时作业效果最佳,钵体完整率为96.44%,取苗成功率为97.06%,满足钵苗移栽作业性能。 展开更多
关键词 番茄 钵苗移栽 探出式 取钵机构 力学分析
下载PDF
可调倾角编程式多功能取苗试验台设计与试验
19
作者 尹大庆 刘港 +1 位作者 张明鑫 王金武 《农业机械学报》 EI CAS CSCD 北大核心 2024年第6期143-149,共7页
针对现有取苗试验台不能满足多种型号钵盘和取苗机构进行取苗试验的需求,设计了一种由多个步进电机驱动、可调取苗机构倾角、可编程控制系统的多功能取苗试验台。该试验台通过调节取苗机构安装支架的位姿、改变钵盘驱动鼠笼钢丝间距以... 针对现有取苗试验台不能满足多种型号钵盘和取苗机构进行取苗试验的需求,设计了一种由多个步进电机驱动、可调取苗机构倾角、可编程控制系统的多功能取苗试验台。该试验台通过调节取苗机构安装支架的位姿、改变钵盘驱动鼠笼钢丝间距以及所在圆周直径,可以适应不同型号钵盘和满足多种取苗机构的试验要求;通过编写控制器程序可控制3个步进电机联动并实现送苗装置的横、纵向送苗与取苗机构取苗进程相匹配。在三维软件中对试验台进行了建模、装配和虚拟仿真,在加工制造的物理样机上进行了2种型号钵盘和3种取苗机构的取苗试验。3次试验结果表明:在此试验台上能够顺利完成取苗试验,证明该试验台满足多种型号钵盘和多种类型取苗机构的试验需求。 展开更多
关键词 钵苗移栽 试验台 横向送苗 取苗机构 编程控制
下载PDF
Design and tests of a rotary plug seedling pick-up mechanism for vegetable automatic transplanter 被引量:6
20
作者 Bingliang Ye Gongjun Zeng +3 位作者 Bin Deng Chiulan Yang Jikun Liu Gaohong Yu 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2020年第3期70-78,共9页
The rotary plug seedling pick-up mechanism for vegetable automatic transplanter is the technical bottleneck to improve the mechanization level of vegetable planting in China.In order to solve the problems of rotary se... The rotary plug seedling pick-up mechanism for vegetable automatic transplanter is the technical bottleneck to improve the mechanization level of vegetable planting in China.In order to solve the problems of rotary seedling pick-up mechanism proposed in previous study,such as low success ratio of seedling pick-up at high speed,and interference between the seedling bowl and the end of the other seedling pick-up arm,a novel kind of rotary seedling pick-up mechanism of planetary gear train with combined type gears of incomplete denatured-eccentric-circular and non-circular gears was proposed.Through kinematic analysis of the seedling pick-up mechanism,the kinematics model was established.The computer-aided analysis and optimization software with human-computer interaction method was developed to realize parameters optimization of the seedling pick-up mechanism.Three-dimensional parametric design system of seedling pick-up mechanisms with combined non-circular gear transmission was developed for mechanism virtual simulation to verify the correctness of theoretical model and design results of the mechanism.The physical prototype of the mechanism was manufactured,and high-speed camera kinematics tests of the mechanism were conducted in the laboratory to study its kinematic characteristics.Laboratory seedling pick-up tests were carried out.The mechanism has the success ratio of seedling pick-up 96.3%without interference during seedling transporting when the rotation speed of the mechanism is 50 r/min and the seedling transplanting efficiency is 100 plants/min per row,showing that the novel mechanism has better working performance than the original one and could be applied in vegetable plug seedling transplanter. 展开更多
关键词 vegetable automatic transplanter rotary seedling pick-up mechanism incomplete denatured-eccentric-circular gear kinematic analysis parametric design
原文传递
上一页 1 2 39 下一页 到第
使用帮助 返回顶部