Correlation Analysis between Well-cellar Early Transplanting of Robust Seedlings and Diseases in Shiyan Tobacco-growing Area

[Objectives]The paper was to investigate the relationship between the well-cellar early transplanting of robust seedlings and the prevalence of diseases in the Shiyan tobacco-growing area.[Methods]The relationship between disease occurrence and meteorological factors during the field growth period was examined by analyzing the prevalence of flue-cured tobacco virus diseases,brown spot,and total disease in the Shiyan tobacco-growing area before(2013-2017)and after(2018-2022)the well-cellar early transplanting of robust tobacco seedlings.[Results]The implementation of a well-cellar early transplanting technique of robust seedlings resulted in a reduction in the average incidence of tobacco virus disease,brown spot,and total disease by 0.83%,8.85%,and 7.91%,respectively,in comparison to the incidence observed prior to early transplanting.These findings suggest that early transplanting can significantly reduce the incidence of flue-cured tobacco diseases.Prior to the well-cellar early transplanting of robust tobacco seedlings,there was a significant(including highly significant)positive correlation between the incidence of brown spot and total disease and precipitation in August and September.The incidence of brown spot and total disease in tobacco plants was found to be significantly positively correlated with May precipitation and significantly negatively correlated with May sunshine hours following the well-cellar early transplanting of robust seedlings.The advancement of the transplanting period by 20 d resulted in a reduction in the growing period of tobacco plants in the field under autumn rains(late August to November)in western China.This effectively circumvented the suitable conditions for disease occurrence and can reduce the incidence of disease.[Conclusions]This study offers a framework for enhancing the quality and efficiency of flue-cured tobacco production in the northwest tobacco-growing area of Hubei.

Study on a Bowl-based Mechanism for Transplanting Potted Strawberry Seedlings

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.

Improving Transportation and Transplanting Efficiency of Flue-cured Tobacco by Transportation of Naked Seedlings

[Objective] The aim was to resolve the problem of low transportation efficiency of seedlings,vulnerability of seedling trays and difficulty of recycling.[Method]Naked seedlings were transported with trays and frames to improve transportation and transplanting efficiency.[Result] The transportation of naked seedlings would effectively reduce transportation cost and improve transportation and transplanting efficiency of tobacco seedlings.[Conclusion] The transportation of naked seedlings is suitable to be applied in the region with professional transplanting.

Research on Potted-Tray Grown Rice Seedling Transplanting by Machine

[Objective] In order to cultivate seedlings that are adaptable to farming system and transplanter, the technology for transplanting potted-tray grown rice seedlings with machine was introduced and studied. [Method] The transplanter-spe-cific seedlings were cultivated with potted-tray, bowl-shaped blanket tray and soft plastic flat plate respectively. The seeding rate and 20-50-day-old seedling height were investigated for the 3 sowing patterns. After the transplanting, the missing transplanting rate, upright seedling rate, seedling injury rate and green-returning pe-riod were investigated. [Result] Nursing seedlings with potted-tray had the advan-tages of saving seeds, high sowing precision, high seedling rate and high seedling rate. The 20-40-day-old seedlings had relatively high leaf age, seedling height and root number. However, 40 d after the transplanting, the growth of seedlings was slowed. The quality difference was smal est among the 20-day-old seedlings that were nursed with 3 different patterns, but since then the quality advantage of pot-ted-tray grown seedlings had been more and more prominent. There was smal dif-ference in quality among the 30-day-old seedlings. However, for the seedlings that were older than 40 d, the transplanting quality of potted-tray grown seedlings was higher than that of bowl-shaped blanket tray grown seedlings and soft plastic flat plate grown seedlings. In addition, the green-returning period of the potted-tray grown seedlings was significantly shortened. [Conclusion] Compared to the bowl-shaped blanket tray grown seedlings and soft plastic flat plate grown seedlings, the potted-tray grown seedlings were more suitable to transplant by machine in the wheat-rice double cropping areas of Chengdu Plain.

Comparison of yield traits in rice among three mechanized planting methods in a rice-wheat rotation system

Understanding the differences in yield traits of rice among pothole seedling of mechanical transplanting （PSMT）, carpet seedling of mechanical transplanting （CSMT） and mechanical direct seeding （MDS） is of great importance not only for rice scientists but also for rice farmers to develop a high-yield production system under mechanical conditions in a rice-wheat rotation system. However, such traits are yet to be studied among rice varieties ofjaponica-indica hybrid rice （JIHR）,japonica conventional rice （JCR） and indica hybrid rice （IHR）. Field experiments were conducted in 2014 and 2015, where six cultivars of the three rice types JIHR, JCR and IHR were grown individually with PSMT, CSMT and MDS methods, under respective managements for each method to achieve the maximum attainable yield. Results showed that （i） the PSMT significantly increased grain yield of JIHR by 22.0 and 7.1%, of JCR by 15.6 and 3.7% and of I HR by 22.5 and 7.4%, compared to MDS and CSMT on average across the two years, respectively. The highest yield was produced by the combination of JIHR and PSMT; （ii） high yield under PSMT was mainly attributed to large sink capacity and high-efficient dry matter accumulation. With sufficient panicles per hectare, the increase of spikelet number per panicle, especially the increase in spikelet number of the secondary rachis-branches was determined to be the optimal approach for developing a large sink capacity for rice under PSMT. The optimal tillers development, large leaf area index at heading stage, and high leaf area duration, crop growth rate and net assimilation rate during grain-filling phase could be the cause of sufficient dry matter accumulation for rice under PSMT; （iii） moreover, the PSMT favored plant growth as well as enriched the stems plus sheaths during grain-filling phase, as compared with CSMT and MDS. These results suggest that PSMT may be an alternative approach to increasing grain yield in a rice-wheat rotation system in the lower reaches of the Yangtze River in China.

Organic Ginger (<i>Zingiber officinale</i>Rosc.) Development in a Short Temperate Growing Season: Effect of Seedling Transplant Type and Mycorrhiza Application

Global warming and consumer demand for medicinal plants present an opportunity to introduce ginger growth to the US Delmarva Peninsula. High tunnel and field studies were conducted to assess the development of organic ginger (Zingiber officinalis, Rosc) seedling transplants in mycorrhiza-amended soil. Transplant types were tissue culture derived with less than three tillers (TCS1), three or more tillers (TCS2), and nontissue culture derived (NTCS1). Transplants were grown with or without mycorrhiza (2.8 g per plant) in a split plot design with soil amendments as main plot and transplant type as subplot. Data were collected for air temperatures, plant height, tiller number, leaf chlorophyll index (LCI), rhizome fresh weight, plant biomass, rhizome nutrients, and levels of As and Pb. TCS2 transplants produced significantly higher, or trended to higher rhizome yield than transplants with less than three tillers, except for year two field study. The maximum rhizome fresh weight per plant was 648.3 g for TCS2 in high tunnel in year one. Generally, TCS2 had most tillers throughout the growing season ranging from 6.9 to 25.7 tillers per plant over three studies. Mycorrhiza had no effect on ginger height, tiller number, LCI or rhizome yield. Sustained high temperatures above 37°C, plus high light in the field caused dieback and stunted shoot growth in year two. There were no consistent effects of mycorrhiza or transplant type on rhizome nutrient content. Content of total Pb, As and other elements were at safe threshold levels for rhizome consumption. These results suggest that gingers grown from TCS2 transplants with at least three tillers yielded more rhizome than those grown from S1 transplants with fewer tillers. Introduction of ginger to a short season region such as the Delmarva may require consideration of environmental condition such as high temperature and light to which seedling transplants may be exposed in summer.

Effects of Seedling Cutivation with Mat-fiber Mulch on Quality and Quantity of Early-season Rice

[Objective] The aim was to explore effects of tray mat of fiber mulch on quality and yield of early rice-season rice transplanted by machine. [Method] Seedling quality, the rate of leaked rice, density of mechanical transplanting rice, mature rate and yield covered with fiber mulch were compared with groups not covered with mulch. Furthermore, different indices of cultivated rice with and without fiber mulch were analyzed and compared. [Result] The rice yield in the group with fiber mulch improved by 11.9% and rice quality enhanced as wel . What＇s more, rice plants were much easier to be col ected, and the rate of leaked rice lowered by machine. [Conclusion] The research provides theoretical references for seedling transplanting and cultivation of early-season rice by machine with tray mats.

Experimental Study on Water Saving of Large-scale Mechanized Paddy Field Production Process in Heilongjiang Province

In order to clarify the water-saving technologies and standards in large-scale mechanized production of paddy fields, the water-saving effects and cost-benefit situations of paddy field steeping, seedling transplanting and different land preparation methods were studied. The results showed that the suitable water layer height for the closing period of mechanized operation was 10 cm, which could save water, facilitate weed control, and lead to better effect and the highest yield. The treatment with a water layer height of 1 cm(Huadashui) for the seedling planting operation achieved better quality of seedling transplanting, lower vacancy rate and higher yield and was water-saving. From the perspective of saving water and taking into account the cost of land preparation, the method of steeping and beating the field was better than the method of plowing in autumn and rotary tillage and harrowing in spring, but it was very prone to lodging. From the perspective of high yield creation, the method of plowing in autumn and rotary tillage and harrowing in spring was significantly better than the method of steeping and beating the field. In order to reduce the cost of land preparation, it is recommended to change the way of plowing in autumn and rotary tillage and hallowing in spring to plowing in autumn and rotary tillage in spring or plowing and hallowing in spring to reduce the cost of one time of rotary tillage, and to simultaneously realize deeper plough layer, which is conducive to preventing lodging and obtaining high yield.

Influence of Transplantation in Different Stage on Growth and Yield of Spring Maize in Shanxi Early Mature Area

In order to explore a new mulch-free maize planting mode and the best seedling age for maize transplantation in Shanxi early mature area,a field experiment was carried out using completely randomized block design.Taking mulch-based direct sowing as the control group,effects of transplantation in different stage on maize growing process,plant height,three-ear leaf area in mature period,and yield and composition factors of maize were studied.Results indicate that growing process of maize seedlings transplanted in every stage is slightly slower than the control group.Transplantation has effect of reducing plant height and three-ear leaf area in mature period.There was no significant difference between the yield of maize transplanted on May 1st and the control group,and the yield declined only by 7% compared with mulch-based direct sowing(CK).Damages to maize seedlings by the local late frost must be noticed when maize is planted by the method of mulch-free transplantation in early mature area.Transplanting the seedlings earlier after the late frost is deemed as an appropriate period in this area.

Design and experimental research on the sweet potato seedling transplanting mechanism of the planetary gear train with deformed elliptical gear transmission

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.

Design and test of 2ZYM-2 potted vegetable seedlings transplanting machine

In order to improve the efficiency and quality of transplanting vegetables in dry land,based on the seedling technology,transplanting effect and analysis of the planting process,a potted vegetable seedlings transplanting machine was designed.It mainly comprised rotary disc type feeding mechanism,five-bar duckbill type planting mechanism(simulated duckbill mechanism,disc cam,connecting rod,crank,fork,cable)and power transmission system.Based on the physical parameters of the seedlings and design requirements,it was determined that the diameter of the duckbill was D=90 mm,the opening and closing angle was 25°,and the taper angle was 17°.A test bench with adjustable parameters was built by analyzing the structure of the planting mechanism and the motion of the working process.The digital speckle technique was used to optimize the parameters,so that the length of the crankshaftΙwas S1=100 mm,the length of the crankshaftΙΙwas S2=80 mm,the length of the connecting rodΙwas S3=140 mm,the length of the connecting rodΙΙwas S4=260 mm,the length of rod to connecting the rack was S6=314 mm,and the height of planting track was H=450 mm.According to the above parameters and the control requirements of the duckbill mechanism,the cam stroke was determined to be S=15 mm.And the initial phase difference between the two cams was 180°.The experiment was carried out with pepper seedlings as transplanting objects.The results showed that when the planting frequency was 50-70 plants/min,the seedling upright rate was 93%-91.1%,the planting depth qualified rate was 96%-92%.The leakage rate was 0-0.26%,the variation coefficient of plant spacing was 0.37%-0.67%,the injury rate was 0%,and the mechanical damage degree of the mining surface was 2.43-3.77 mm/m2.The machine can effectively improve the quality of transplanting,which can meet the production needs and design requirements of the mechanism.

Development of a metering mechanism with serial robotic arm for handling paper pot seedlings in a vegetable transplanter

This paper describes the development of an automated metering mechanism for vegetable transplanter.It consisted of a 3-DOF serial robotic arm and an automatic feeding conveyor.The robotic arm was developed to pick and drop tomato seedlings raised in biodegradable paper pots.The volume of each pot was 50 cm^(3)(3.5 cmdiameter and 5.2 cmheight)with a maximumtotalweight of 47 g including potmix and seedling.Amatrix type feeding conveyorwas developed to convey the pot seedlings to a predefined positionwhere the robotic armcould pick up these seedlings one by one.LDR(Light Dependent Resistor)-LED(Light Emitting Diode)sensing unit was used to perform the intermittent movement of the conveyor.The developed system was evaluated under both laboratory and field conditions.The robotic arm was able to pick and drop 20 seedlings per minute and its effective cycle time per handling one seedling was varying from 2.5 to 3.1 s.Power consumption of the conveyor of the developed system and the robotic arm was 18 W and 16 W,respectively.The conveying,metering and overall efficiency of the developed metering mechanism under laboratory condition were 96.83%,95.91%and 92.86%,respectively as compared to 94.7%,93.28%and 88.33%,under field condition.The developed robotic armbasedmeteringmechanismwas simple,light inweight and effectively handled the pot seedlings without damage and would thus help in mechanizing transplanting of vegetable seedlings.

Kinematic analysis and experiment of planetary five-bar planting mechanism for zero-speed transplanting on mulch film

A novel seedling transplanting mechanism with planetary five-bar was developed in order to solve some problems when transplanting seedlings on mulch film,such as a large cave diameter,a low proportion of upright seedlings,and inconsistent planting depths,which seriously restrict the development of transplanting equipment used in dryland agriculture.The planetary five-bar structure of transplanting mechanism was designed based on analysis of the seedling transplanter on mulch film.The kinematics model of the transplanting mechanism was established and the optimal parameters of the transplanting mechanism were obtained by satisfying the motion trajectory conditions.Subsequently,the virtual prototype of transplanting mechanism was developed,and the simulation of motion trajectory was illustrated.Finally,the physical prototype of the transplanting mechanism was assembled and tested with the high-speed photography.The simulation results indicated that the desired“spindle”trajectory for the duckbill can be obtained,of which the height was 350 mm,and the diameter of the planting cave was 32 mm.The experimental results showed that the diameter of the planting cave was less than 70 mm,the seedling perpendicularity qualification rate reached 96%,the film injury rate was less than 0.5%,and the hanging membrane phenomenon was avoided.Therefore,the proposed transplanting mechanism can meet the requirements for a mulch-film transplanting machine.

Seedling-growing tray made of rice straw for maize seedling transplantation and its shear mechanics test

The plant-made seedling-growing tray cultivation technique is an effective way to improve maize yield and quality in China’s cold northern area.However,the corn seedling nursery carrier and tray cultivation technique has been proved poor in adaptability.After comparing several nursery carriers,a design for a plant-made seedling-growing tray that is suitable for maize transplantation was proposed in which rice straw was used as the primary raw material.The preparation method,processing and structural dimensions of the tray were investigated and designed,five types of plant-made seedling-growing trays with different formulations were proposed.The shear mechanical properties and the shear strength of the plant-made seedling-growing trays were tested to determine the shear force needed for cutting through trays prepared with increasing mass ratios of rice straw and the effect of the shearing rate on the shear strength.The results showed that at a shearing rate of 100 mm/min,the maximum shear force decreased gradually as the mass ratio of straw was increased and that the hardness of the tray decreased as its shear strength decreased.Under three shearing rates(100 mm/min,200 mm/min and 500 mm/min)and a blade displacement of 10 mm,the shear force was the highest at the point at which the tray was cut through;the required shear force to cut through the tray then gradually decreased.Trays with the same straw composition showed no significant influence of shearing rate on the tray’s shear strength at shearing rates of 100 mm/min,200 mm/min or 500 mm/min.This study describes a multi-tray,single-strip nursery carrier for use in plant-made seedling-growing tray cultivation and proposes a theoretical basis for the design of a rotary transplanting device,the key part of a maize plant-made seedling-growing tray transplanter.

Seedling-lump integrated non-destructive monitoring for automatic transplanting with Intel RealSense depth camera

Non-destructive plant growth parameters measurement is an important concern in automatic-seedling transplanting.Recently,several image-basedmonitoring approaches have been proposed and potentially developed for several agricultural applications.The presented study proposed and developed a RealSense-based machine vision system for the close-shot seedling-lump integrated monitoring.The strategy was based on the close-shot depth information.Further,the point cloud clustering and suitable algorithms were applied to obtain the segmentation of 3D seedling models.In addition,the data processing pipeline was developed to assess the differentmorphological parameter of 4 different seedling varieties.The experiments were carried out with 4 different seedling varieties(pepper,tomato,cucumber,and lettuce)and trained under different light conditions(light and dark).Moreover,analysis results showed that therewas not significantly different(p<0.05)found towards light and dark environments due to close-shot near-infrared detection.However,the results revealed that the stem diameter relationship between RealSense and the manual method was found for R^2=0.68 cucumber,R^2=0.54 tomato,R^2=0.35 pepper,and R^2=0.58 lettuce seedlings.Whereas,the seedling height relationship between RealSense and the manual methodwas found higher than R^2=0.99,0.99,0.99,and 0.99 for pepper,tomato,cucumber,and lettuce,respectively.Based on the experiment results,it was concluded that the RGB-D integrated monitoring system with the purposed method could be practiced for nursery seedlings most promisingly without high labour requirements in terms of ease of use.The system revealed a good sturdiness and relevance for plant growth monitoring.Additionally,it has the perspective for future practical value to real-time vision servo operations for transplanting robots.