Plug Trays Research Articles

Segmentation-Based Detection for Luffa Seedling Grading Using the Seg-FL Model

This study addresses the issue of inaccurate and error-prone grading judgments in luffa plug seedlings. A new Seg-FL seedling segmentation model is proposed as an extension of the YOLOv5s-Seg model. The small leaves of early-stage luffa seedlings are liable to be mistaken for impurities in the plug trays. To address this issue, cross-scale connections and weighted feature fusion are introduced in order to integrate feature information from different levels, thereby improving the recognition and segmentation accuracy of seedlings or details by refining the PANet structure. To address the ambiguity of seedling edge information during segmentation, an efficient channel attention module is incorporated to enhance the network’s focus on seedling edge information and suppress irrelevant features, thus sharpening the model’s focus on luffa seedlings. By optimizing the CIoU loss function, the calculation of overlapping areas, center point distances, and aspect ratios between predicted and ground truth boxes is preserved, thereby accelerating the convergence process and reducing the computational resource requirements on edge devices. The experimental results demonstrate that the proposed model attains a mean average precision of 97.03% on a self-compiled luffa plug seedling dataset, representing a 6.23 percentage point improvement over the original YOLOv5s-Seg. Furthermore, compared to the YOLACT++, FCN, and Mask R-CNN segmentation models, the improved model displays increases in mAP@0.5 of 12.93%, 13.73%, and 10.53%, respectively, and improvements in precision of 15.73%, 16.93%, and 13.33%, respectively. This research not only validates the viability of the enhanced model for luffa seedling grading but also provides tangible technical support for the automation of grading in agricultural production.

Growing Vigorous Potato Seedlings in Plug Trays

AbstractRaising vigorous and healthy potato seedlings from hybrid true potato seeds (TPS) under nursery conditions is critical for ease of field transplanting and seedling crop establishment as well as for a productive seed or ware crop. The use of plugs in seedling production systems is an important technique utilised to ease transplanting of seedlings and refine seedling production in seedling nurseries. While holding multiple advantages over other transplant production systems, multiple factors still influence the success of seedling production in plug trays. In this study, we explore the effects of substrate properties, type and volume; watering intervals; and nitrogen (N) and phosphorus (P) levels in nutrient solution on seedling vigour attributes in potato seedlings grown in plug trays under climate room conditions. The choice of substrate strongly influenced seedling attributes with more favourable performance in substrates with higher water holding capacity. Increasing plug volume also enhanced seedling attributes including dry biomass, leaf area and root to shoot ratios such that seedling performance was best in plug volumes > 22.5 cm3. A watering schedule with a high frequency was more favourable considering that longer intervals between watering events led to significant declines in seedling attributes. While the effects of increased P in solution were not conclusive, depending on genotype, increasing N in solution led to enhanced seedling attributes, with a nutrient sufficiency met at 200 mg L−1 N in solution. These findings further contribute to the current knowledge on factors influencing success in seedling production of potato seedlings developed from hybrid true potato seeds.

Variation in Phenology and Morphological Traits of Seed-Propagated Laggera alata and Laggera crispata Forms

The phenological and morphological variation studies among forms of Laggera Sch. Bip. Ex. Benth. and Hook species are limited, despite the medicinal use of the genus. Therefore, this study aimed to document phenology and morphological variation in cultivated populations of Laggera alata and Laggera crispata forms from seedling to maturity. The forms were categorized as Laggera alata with a small capitulum (LA-SC), Laggera alata with a large capitulum (LA-BC), Laggera crispata from South Africa (LC-SA), and Laggera crispata from Zimbabwe (LC-ZIM). Seeds were germinated in Petri dishes, transplanted to plug trays, and later to field plots at 60 days. Phenological events were recorded when observed in at least one plant. Twelve qualitative and four morphometric traits were measured monthly on five plants per Laggera form. Analysis of variance and Tukey’s Honestly Significant Difference test (p < 0.05) were used for data analysis. Results indicated significant variation in phenology, qualitative traits, leaf traits, plant height, and stem diameter both within and between L. crispata and L. alata forms. Morphometric traits, such as leaf size and the number of leaves per plant, were identified as key descriptors for differentiating L. alata forms. These findings provide a foundation for the introduction of Laggera forms into farming systems for medicinal and commercial purposes.

Effect of different growing media on growth, yield and quality of microgreens under greenhouse condition

The present investigation entitled “Effect of different growing media on growth, yield and quality of microgreens under greenhouse condition”was carried out at Hi-tech Horticultural Park, College of Horticulture, Junagadh Agricultural University, Junagadh during the year 2023. The experiment was laid out in Completely Randomized Design with factorial concept (FRBD) with two factors. The treatments consisted of three levels of growing media i.e., Soil + Vermicompost (1:1 V/V), Cocopeat + Vermicompost (1:1 V/V) and Soil + Cocopeat + Vermicompost (1:1:1 V/V/V) with five levels of crops i.e., Fenugreek, Onion, Palak, Beet root and Red cabbage. The results on interaction effect of growing media and crops indicated that the treatmentcombination of G3C5 [{Soil + Cocopeat + Vermicompost (1:1:1 V/V/V)} + Red cabbage] recorded maximum germination (89.33 %), number of cells harvested per plug tray (47.67), percentage of cells harvested per plug tray (88.27 %), antioxidant activity (52.10 %), carotenoids content (12.46 mg/100 g)and minimum mortality (1.19 %).However, G2C2 [{Cocopeat + Vermicompost (1:1V/V)} + Onion] recorded maximum length of microgreens (9.17 cm), G2C1 [{Cocopeat + Vermicompost (1:1 V/V)} + Fenugreek]recorded maximum root length (4.84cm), G2C5 [{Cocopeat +Vermicompost (1:1 V/V)} + Red cabbage] recorded maximum number of roots (5.07) and G3C4 [{Soil + Cocopeat + Vermicompost (1:1:1 V/V/V)} + Beet root] recorded maximum yield per plug tray (19.93 g). Whereas, maximum chlorophyll content (1.21 mg/g) was noted in G3C3 [{Soil + Cocopeat + Vermicompost (1:1:1 V/V/V)} + Palak].

INDIGENOUS CUCURBITS AND GRAFTING TECHNIQUES AFFECT CUCUMBER PRODUCTIVITY BY MODULATING MORPHO-PHYSIO-BIOCHEMICAL INDICES

Vegetable grafting is a unique surgical horticultural technology for inducing soilborne biotic and abiotic stress tolerance in cucumbers. Indigenous cucurbit germplasm as rootstocks may show more tolerance potential compared to exotic ones. However, it needs evaluation for compatibility testing through various grafting techniques. Therefore, this study was planned to test available cucurbits as rootstocks for graft success vis-à-vis cucumber growth and productivity. It was carried out in the Plant Propagation and Physiology lab at MNS University of Agriculture, Multan, Pakistan. The seeds of the indigenous open-pollinated cucurbits were sown in 64-celled plug trays with peat moss as growing media, followed by shifting to 50-celled plug trays at the first true leaf emergence stage. The seeds of selected scion (cucumber) were sown after the emergence of rootstock seeds. Different grafting techniques were performed at the first true leaf stage of the scion, followed by healing and acclimatization. In this experiment, hybrid cucumber (cv Yalla F1) was grafted on three indigenous cucurbits, namely ridge gourd (Luffa acutangular), bottle gourd (Lagenaria sicearia) and pumpkin (Cucurbit pepo. L) for graft compatibility success by using three grafting techniques: cleft grafting, one cotyledon grafting and hole insertion. Non-grafted cucumber was grown to compare with grafted plants for growth and productivity. Overall, significant (p ≤ 0.5%) results were obtained regarding a 90% survival rate in cucumber plants grafted onto the bottle gourd through cleft grafting compared to the other grafting techniques. Additionally, the cucumber plants grafted on bottle gourd showed the highest morphological (root length, shoot length, root fresh weight, shoot fresh weight and rootstocks, and scion gir th), physiological (photosynthetic rate, transpiration rate, stomatal conductance, and sub-stomatal conductance), biochemical (antioxidants activities, SOD, CAT, and POX) and yield indices (average fruit length, weight, numbers, and yield) as compared to the non-grafted plants. Conclusively, cucumber grafting onto indigenous bottle gourd with cleft grafting technique exhibited maximum compatibility confirmed through physio-chemical attributes and improved plant biomass and yield, thereby suggested for cucumber grafting.

Valorization of vermicompost: effects on morpho-physiological parameters of organic tomato plantlets (Solanum lycopersicum L.)

This study was conducted to explore the effect of vermicompost on the growth and physiological parameters of the tomato plant (Solanum lycopersicum L.). The experiment was carried out in a complete random block design. In the initial nursery phase, different percentages (20, 30, and 40%) of vermicompost/compost were used, and the mixture containing 15% of each was evaluated in the cell plug trays. In the transplanting phase, seedlings randomly selected based on their superior growth performance from treatments involving 20% compost/vermicompost, as well as the mixture were subsequently transplanted into pots filled with organic soil. Plants were monitored until the flowering stage, and measurements were taken at different growth stages of the plant, such as shoot length, stem diameter, number of leaves, root length, fresh and dry weight of the plant. Moreover, some physiological parameters, such as chlorophyll and carotenoid contents, were assessed. An ANOVA using SPSS was used to process the data collected from the experiment. The results showed that vermicompost treatments induced a significant increase in shoot length, stem diameter, leaves number, root length, contents of chlorophyll a and carotenoid of tomato plants compared to the control, with an improvement of 54, 38, 38, 70, 44, and 69.5%, respectively. These findings highlight the potential of vermicompost as a potential nutrient source for crop production.

Design, Integration, and Experiment of Transplanting Robot for Early Plug Tray Seedling in a Plant Factory

In the context of plant factories relying on artificial light sources, energy consumption stands out as a significant cost factor. Implementing early seedling removal and replacement operations has the potential to enhance the yield per unit area and the per-energy consumption. Nevertheless, conventional transplanting machines are limited to handling older seedlings with well-established roots. This study addresses these constraints by introducing a transplanting workstation based on the UR5 industrial robot tailored to early plug tray seedlings in plant factories. A diagonal oblique insertion end effector was employed, ensuring stable grasping even in loose substrate conditions. Robotic vision technology was utilized for the recognition of nongerminating holes and inferior seedlings. The integrated robotic system seamlessly managed the entire process of removing and replanting the plug tray seedlings. The experimental findings revealed that the diagonal oblique-insertion end effector achieved a cleaning rate exceeding 65% for substrates with a moisture content exceeding 70%. Moreover, the threshold-segmentation-based method for identifying empty holes and inferior seedlings demonstrated a recognition accuracy surpassing 97.68%. The success rate for removal and replanting in transplanting process reached an impressive 95%. This transplanting robot system serves as a reference for the transplantation of early seedlings with loose substrate in plant factories, holding significant implications for improving yield in plant factory settings.

Prohexadione-Calcium Mitigates the Overgrowth of Corn Seedlings

In the temperate climate of South Korea, specific corn varieties are cultivated using plug trays. The cultivation process is initiated from February to March within greenhouse facilities, maintaining a temperature below 10 degrees Celsius. Following this, in April, seedlings are transplanted to enable an exceptionally early harvest for increased profitability. However, the subsequent elevation in indoor temperatures leads to seedling overgrowth. This study explores the effectiveness of three plant growth regulators—paclobutrazol, prohexadione-calcium, and diniconazole–on super sweet corn seedlings. Significantly, the application of prohexadione-calcium at 2 ppm during the first leaf stage substantially reduces seedling height and impedes the growth of both the first and second internodes. This impact extends to leaf-related traits, manifesting reductions in the area, length, and width of the third leaf. Furthermore, prohexadione-calcium induces a significant decrease in both fresh and dried shoot weight, while simultaneously augmenting root weight. This alteration results in a noteworthy shift in the root–shoot ratio, particularly at 2 ppm. Subsequent experiments have identified the optimal concentration of prohexadione-calcium at 15 ppm, effectively mitigating overgrowth in both hybrid and inbred corn varieties. These findings provide essential insights for practitioners seeking to efficiently manage corn seedling overgrowth. The study contributes to understanding the retardant effect of prohexadione-calcium on various morphological traits, offering practical applications for optimizing plant growth regulator concentrations in corn cultivation strategies.

Design and Implementation of the Positioning and Directing Precision Seeder for Cucurbita Ficifolia Seeds

Highlights Identification of large seed plantule point direction were realized using machine vision. A large seed orientation seeder is designed to achieve automatic orientation seeding of large seeds. The directional seeding success (deflection angle of less than 15°) rate was 92.89%. The qualified rate of positioning and orientation reached 87.80% Abstract. A consistent plantule point and a uniform distribution of cucurbit seeds are required for factory seedlings and grafting. However, precision sowing Cucurbita ficifolia seeds automatically with a positioning and orientation method is difficult due to their large, non-spherical shape. To overcome this challenge, a machine vision-based precision seeder was designed specifically for Cucurbita ficifolia seeds. To achieve consistent seed placement and orientation at a 45° angle, a method using machine vision and precise seed positioning and orientation has been proposed. The plantule point location was determined by comparing the pixel values at both ends of seed. The positioning and orientation module was developed to achieve seeding with same orientation of plantule point and located in the center of the plug tray. Finally, the positioning and orientation precision seeder for seeds were tested and evaluated. The results showed that the accuracy rate of seed plantule point identification and the success rate of the seeds orientation actuator were 97.56% and 100.00%. 95.21% of seeds achieved a deflection angle of less than 15°. The germination port of 96.06% of the seeds is distributed in a circle with the center of the hole as the center and a radius of 10 mm. The qualified rate of positioning and orientation reached 87.80%, and the sowing efficiency was about 3750 grains/h. The results showed that the seeder achieves the consistent orientation of the germination port of seeds and sows the seeds in the center of the hole. This finding provides technical support for seedling testing and large-scale factory seedlings. Keywords: Cucurbita ficifolia seeds, Machine vision, PLC control, Positioning and orientation, Precision seeder.

Effects of plug tray cell size on the growth of Atractylodes Chinensis (DC) Koidz seedlings

Effects of plug tray cell size on the growth of Atractylodes Chinensis (DC) Koidz seedlings

Prediction of Growth and Quality of Chinese Cabbage Seedlings Cultivated in Different Plug Cell Sizes via Analysis of Image Data Using Multispectral Camera

In recent times, there has been an increasing demand for the development of rapid and non-destructive assessment of the growth and quality of seedlings before transplanting. This study was conducted to examine the growth and quality of Chinese cabbage seedlings that can be determined via the image data acquired using a multispectral camera. Chinese cabbage seedlings were cultivated in five different plug trays (72, 105, 128, 162, and 200 cells/tray) for 30 days after sowing (DAS). The growth of seedlings had no significant difference in the early stage of cultivation; however, it decreased with increasing the number of cells in the plug tray due to the restricted root zone volume in the mid to late stages. Individual leaf area was predicted by analyzing of image data with high accuracy (R2 > 0.8) after 15 DAS; however, the accuracy of leaf area prediction per tray decreased due to overlapping and twisting leaves. Among six different vegetation indices, mrNDVI showed a high correlation (R2 > 0.6) with the dry weight of seedlings at 25 and 30 DAS. We confirmed that the leaf area of seedlings can be predicted non-destructively by analyzing the acquired image data per seedling and tray and suggested the applicability of vegetation indices for predicting the growth and quality of vegetable seedlings.

Development of Simplified Seedling Transplanting Device for Supporting Efficient Production of Vegetable Raw Materials

Efficient greenhouse production has a great supporting role in the development of vegetable agricultural and sideline product processing. In this paper, a simplified automatic transplanting device was designed and evaluated in a laboratory. The device mainly consists of a seedling pick-up gripper, a transplanting manipulator, two conveyors and a control system. The flexible multi-pin gripper was designed to effectively grasp, hold, and release seedlings. Through a combination innovation of the linear modules, the transplanting manipulator was designed to move the seedling gripper to the desired working position. The conveyors were the pallet-type double-row chain transmission system for automatic feeding of plug trays and growth pots. The control system was developed to coordinate each of the aforementioned function units. The multi-factor orthogonal and transplanting performance experiments were carried out under the standard seedling agronomy. The results showed that the transplanting frequency and the pick-up depth significantly affected the transplanting quality. When the transplanting frequency was 15 plants/min, the tightened spring force was 1.2 N, and the pick-up penetration depth was 35 mm, the optimum effects of automatic transplanting seedlings could be achieved. The maximum success in transplanting seedlings was 95.47% for local vegetable crops. The developed prototype could realize less waste of seedling resources at the farm level.

Implementing a Precision Pneumatic Plug Tray Seeder with High Seeding Rates for Brassicaceae Seeds via Real-Time Trajectory Tracking Control

In recent years, the aging of the rural population worldwide has become a major concern, necessitating the development of agricultural automation. Pneumatic energy has emerged as a reliable and environmentally friendly option, aiding in the global effort to reduce carbon emissions. The purpose of this study is to reduce the amount of labor required for plug tray seeding by developing an automated seeder that employs a precision pneumatic servo system via the rod-less actuator with real-time trajectory tracking capabilities. The proposed seeder has a simple structure, is easy to maintain, and saves energy. It mainly consists of a rod-less pneumatic cylinder, a needle seeding mechanism, a soil drilling mechanism and a PC-based real-time controller. Mathematical models of the developed precision pneumatic plug tray seeder are analyzed and established, and an adaptive sliding mode controller is proposed. A PC-based real-time control system is developed using MATLAB/SIMULINK via an optical encoder with a sampling frequency of 1 kHz to enable the development of precise pneumatic plug tray seeder. An optical encoder is used to measure the displacement of the rod-less cylinder which represents real-time positions of the plug tray loading platform. Experiments are conducted using Brassicaceae seeds, and the rates of single seeding, multiple seeding, missed seeding and germination are carried out through manual measurement. The results indicate that the seeder exhibits satisfactory performance, with a root mean square error of less than 0.5 mm and a single-seeding rate of more than 97%. Overall, our findings provide new insights for nurseries and could contribute to the reduction in agricultural carbon emissions.

Effect of soil salinity on germination and survival of brinjal (Solanum melongena L.)

The present investigation was conducted at vegetable research farm, Department of Vegetable Science, Punjab Agricultural University, Ludhiana. The desired levels of salinity were induced using sodium chloride, magnesium sulphate and calcium chloride in ratio of 2:1:1. Seeds of 102 brinjal genotypes were sown in plug trays. Each brinjal genotype was sown in two (Plug trays) sets. In each plug tray, 28 plants were sown. In one set of plug tray, normal water was applied. When seedlings attained 2 leaf stage (after 10–12 days of sowing), saline water treatment was applied to evaluate seedling survival under salt stress conditions. While in the second set of plug tray, saline water was applied immediately after sowing to evaluate germination percentage under salt stress conditions. It has been observed from the investigation that these genotypes were categorized as 19 genotypes under tolerant, 39 as semi-tolerant and 44 were susceptible to salinity on the basis of nursery and morphological screening trials. Out of these 19 tolerant genotypes, brinjal genotypes (SL-8-PB-1-3- 1-4 (Small Long), KBSR-343-1 (Small round) and BL-215 (Long)) may be recommended for future studies in salt-affected area of Punjab.

Nondestructive detection of key phenotypes for the canopy of the watermelon plug seedlings based on deep learning

Nondestructive measurement technology of phenotype can provide substantial phenotypic data support for applications such as seedling breeding, management, and quality testing. The current method of measuring seedling phenotypes mainly relies on manual measurement which is inefficient, subjective and destroys samples. Therefore, the paper proposes a nondestructive measurement method for the canopy phenotype of the watermelon plug seedlings based on deep learning. The Azure Kinect was used to shoot canopy color images, depth images, and RGB-D images of the watermelon plug seedlings. The Mask-RCNN network was used to classify, segment, and count the canopy leaves of the watermelon plug seedlings. To reduce the error of leaf area measurement caused by mutual occlusion of leaves, the leaves were repaired by CycleGAN, and the depth images were restored by image processing. Then, the Delaunay triangulation was adopted to measure the leaf area in the leaf point cloud. The YOLOX target detection network was used to identify the growing point position of each seedling on the plug tray. Then the depth differences between the growing point and the upper surface of the plug tray were calculated to obtain plant height. The experiment results show that the nondestructive measurement algorithm proposed in this paper achieves good measurement performance for the watermelon plug seedlings from the 1 true-leaf to 3 true-leaf stages. The average relative error of measurement is 2.33% for the number of true leaves, 4.59% for the number of cotyledons, 8.37% for the leaf area, and 3.27% for the plant height. The experiment results demonstrate that the proposed algorithm in this paper provides an effective solution for the nondestructive measurement of the canopy phenotype of the plug seedlings.

Key Technologies of Plug Tray Seedling Transplanters in Protected Agriculture: A Review

The process of plug tray seedling transplanting is a crucial step in protected agriculture production. Due to issues such as high labor intensity, poor consistency of work quality, and low efficiency, the application of automated transplanting machines has provided a solution to these issues. For the diversity of transplanting operations, various mechanical structures and technological applications have been developed for automated transplanting equipment. Therefore, this paper provides systematic research of current studies on the key transplanter technologies. Firstly, through an analysis of the types of transplanting operations, the technical requirements of automated transplanting equipment for different operation types are elucidated. Subsequently, the key technologies applied in transplanting machines are discussed from the perspectives of substrate physical characteristics, end effectors, integration of multiple end effectors, vision systems, and transplanting path planning. Moreover, an analysis is conducted on the advantages, disadvantages, and application scenarios of different research methods for each key technology. Lastly, the existing problems and technical difficulties of the transplanting machine are summarized, and future research directions are discussed. This analysis provides a valuable reference for further research and development in the field of transplanting machines for plug tray seedlings.

Morphological, Phytochemical, and Photosynthetic Performance of Grafted Tomato Seedlings in Response to Different LED Light Qualities under Protected Cultivation

Healing and acclimatization are critical in vegetable grafting under controlled environments. Here, we investigated the impacts of LED light qualities on the morphological traits and photosynthetic performance of grafted tomato seedlings. Seeds of the tomatoes “DRW 7806 F1” and “Maxifort” (Solanum lycopersicum × Solanum habrochaites) used as scion and rootstock were planted in 104-cell plug trays into a mixture of cocopeat and perlite (volume ratio: 3 to 1). Survival ratio, above- and underground growth, photosynthetic performance, soluble carbohydrate content, pigmentation, and antioxidant enzymes activity were evaluated following 20 days of exposure to different light qualities, including white (35% B, 49% intermediate spectra, 16% R) light as control, blue, red, and a combination of red (68%) and blue with the same light intensity of 75 ± 5 µmol m−2 s−1. The lowest scion diameter, leaf area, root and shoot dry weight, SPAD value, and the highest scion length and amount of soluble carbohydrate were detected in R-exposed seedlings. Moreover, R-exposed seedlings showed leaf epinasty and reduced photosynthetic performance. On the other hand, RB-exposed seedlings showed the highest leaf area, shoot and root dry weight, plant fresh and dry weight, scion stem diameter and photosystem II efficiency. In addition, superoxide dismutase activity was increased in R-exposed seedlings, while guaiacol peroxidase activity was enhanced in seedlings grown in RB. In conclusion, a combination of R and B is suggested as the suitable light spectrum to promote plant growth and photosynthetic performance in grafted tomato seedlings.

Machine vision-based tomato plug tray missed seeding detection and empty cell replanting

The current tomato plug tray sowing methods are plagued by the issue of missed sowing. Consequently, the detection of missed sowing and empty cells replenishment of tomato plug trays after initial sowing is an important prerequisite to realizing precision sowing of plug trays and improving the quality of plug tray seedlings. This study proposed a machine vision-based information perception method for tomato plug trays to detect missed seeds and replenish empty cells. First, based on a YOLOv5x network model, deep learning training was employed to obtain a detection model for identifying tomato seeds in complex backgrounds of plug trays. Thereafter, the location of the tomato seeds was compared with the coordinate value of the edge of the hole, and the missed holes were detected. Based on the missed cells detection results, the empty cell coordinates were converted into replanting coordinates, and the plug tray conveyor and the replanting suction needle are controlled separately considering the replanting row information to replant the missed cavities row by row. Further, the tomato plug tray missed seeding detection and replenishment device was built and tested at a seedling greenhouse. The results indicated an average detection accuracy of 92.84 % with average detection time per tray of 13.475 s. The success rate of replanting on trays was determined to be 91.7 % with 5 %-20 % misses. In addition, the productivity of the tray was approximately 42.4 trays/h. Thus, the proposed method of detecting and replanting misses in tomato trays can be used to improve the performance of tomato seeding. Moreover, it can be used as a reference to improve the precision and efficiency of tomato seeding in plug trays.

Ornamental cabbage (Brassica oleracea var. acephala) responses to phytase enzyme purified from Lactobacillus coryniformis application.

In order to increase the quality and yield of ornamental plants, especially potted ornamental plants, it is necessary to enrich the physical properties of the growing medium and to ensure the continuity of the growing medium. In order to achieve this, organic substances that create a serious cost in ornamental plant cultivation are added to the growing medium. This study was planned to assess the role of inoculation of different levels in the seeds and soaking times of purified phytase, on the plant growth and ornamental plant decorative values in ornamental cabbage plants under nutrient limiting condition in greenhouse. Different doses (E0 : 0 EU, E1 : 5 EU, E2 : 10 EU), soaking times (W15 : 15min, W30 : 30min, W60 : 60min), and their combinations (W15 + E0 , W15 + E1 , W15 + E2 , W30 + E0 , W30 + E1 , W30 + E2 , W60 + E0 , W60 + E1 , W60 + E2 ) of phytase enzyme purified and isolated from the Lactobacillus coryniformis were applied to ornamental cabbage seeds, and they were sown in plug trays filled with appropriate growing medium. Seedlings were planted in plastic pots during their period when the seedlings had four to five true leaves. Treatments of phytase enzyme purified and isolated from the microorganism generally improved the observed parameters. The application of, especially, the highest level of phytase enzyme doses increased the plant height, main stem height, and stem diameter of ornamental cabbage as compared to control (E0 treatment: distilled water). While the highest number of leaves per plant was obtained at E1 and E2 application doses and W30 and W60 soaking times; the highest stem diameter was obtained at E2 application doses and W30 and W60 soaking times. The present study clarified that the purified phytase enzyme can increase ornamental cabbage quality at the appropriate concentration and soaking time and is a promising biotechnology material for agricultural applications, and especially in different ornamental plant species.

Airflow ejection-wrapped clamping type seedling picking method and parameter optimization.

Since the current clamp-type and push-out-type seedling picking method brought damage to seedlings, this study aimed to proposed an airflow ejection-wrapped clamping type seedling picking method, which used airflow to eject out seedling and the seedlings were wrapped clamped to reduce the damage of seedlings during seedling picking process. The parameter model was established through theoretical design, then the parameters were optimized through coupling simulation analysis, and the validity of these parameters was verified through experiments. We found that the diameter of the airflow nozzle was selected as 3.5mm to match with the drainage outlet of the plug tray, and the airflow pressure which could eject out seedlings was calculated as 0.146 Mpa~0.315 Mpa on the basis of gas jet dynamic. The fluid-solid coupling simulation of airflow ejection in Comsol proposed that the seedlings could be ejected out under the airflow pressure was equal to or greater than 0.4 Mpa, and the airflow should be maintained for about 0.3 s to ensure the posture of the seedlings ejected out for better seedling clamping. The further fluid-discrete body simulation of airflow ejection by using Fluent-Edem coupling method indicated that the seedling was damaged under airflow pressure of 0.5 MPa, so the airflow pressure should be set as 0.4 MPa during seedling ejection process. Besides, a wrapped clamping type effector which clamped the seedlings from all sides in the form of flexible package was also designed to match with the airflow ejection method, and the RecurDyn-Edem coupling simulation showed that the end-effector could tightly clamp the seedling without damage when the angle between the clamping slices and the vertical direction was 8.5°. Finally, the airflow ejection-wrapped clamping type seedling picking device was manufactured, and the verification tests verified the simulation results. This research can provide some references for the automatic seedling picking technology.