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 crankshaft Ι was S1=100 mm, the length of the crankshaft ΙΙ was S2= 80 mm, the length of the connecting rod Ι was S3=140 mm, the length of the connecting rod ΙΙ was 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. Keywords: seedling transplanting, planting mechanism, digital speckle, parameter optimization, test analysis DOI: 10.25165/j.ijabe.20201301.5494 Citation: Jin X, Cheng Q, Zhao B, Ji J T, Li M Y. Design and test of 2ZYM-2 potted vegetable seedlings transplanting machine. Int J Agric & Biol Eng, 2020; 13(1): 101–110.

In order to improve the quality of oil peony transplanting, based on the characteristics of peony seedlings and the transplanting effect, the transplanting process was analyzed. A peony seedling transplanting machine was designed, which was mainly composed of a chain-clamp type planting mechanism (clamp, transmission chain, sprocket), slideway, profiling wheels, trencher, the power transmission system and rack. Through the movement analysis of the planting mechanism and its operation process, its structural parameters were optimized. The effective length of the clamp was determined as L1=235 mm, the adjustment range was 235-285 mm, and the height of the planting trajectory was H=340 mm. Based on the physical characteristics and mechanical characteristics of the peony seedlings, the parameters of the slideway and the putter were determined. The effective length of the slideway was determined as L2=420 cm, the width T2=105 mm, the distance between the slideways S=45 mm. The initial angle difference of the putter was θ=13°, and the putter rotation angle β=37°, putter height ratio ε=2. Based on the above parameters and design requirements, the radius of the planting sprocket R1=42 mm, R2=80 mm. “Feng Dan” peony seedlings were used as transplantation test objects. The results showed that: when the planting frequency was 60-75 plants/min, the upright rate was 89.2%-92.8%, the leakage rate was 0-0.28%, the injury rate of seedlings was 0, and the qualified rate of planting depth was 91.7%-95.3%, the variation coefficient of plant spacing was 0.25%-0.54%. This machine can effectively improve the quality and efficiency of transplanting, meeting the requirements of mechanical design and production needs. Keywords: peony transplanting, planting mechanism, oil peony, peony seedlings, parameter design, test analysis DOI: 10.25165/j.ijabe.20201304.5695 Citation: Ji J T, Cheng Q, Jin X, Zhang Z H, Xie X L, Li M Y. Design and test of 2ZLX-2 transplanting machine for oil peony. Int J Agric & Biol Eng, 2020; 13(4): 61–69.

To understand the physiological responses of seedlings to mechanical wounding, we analyzed photosynthesis, chlorophyll fluorescence, and endogenous hormones in tomato (Solanum lycopersicum L.) subjected to varying levels of mechanical pressure. The results showed that, at 4 h after wounding, excess excitation energy was dissipated as thermal energy through the reduction in the photosystem II (PSII) opening degree and the increase in non-photochemical quenching. Photodamage was avoided, and stomatal closure was the most prominent factor in photosynthesis inhibition. However, 12 h after wounding, the photoprotective mechanism was insufficient to mitigate the excess excitation energy caused by the wound, leading to photochemical damage to physiological processes. Meanwhile, the non-stomatal factor became the most prominent limiting factor for photosynthesis at 80 N pressure. At 12 and 36 h after wounding, the concentrations of abscisic acid (ABA), methyl jasmonate (MeJA), indole-3-acetic acid (IAA), zeatin riboside (ZR), and gibberellic acid (GA₃) in the stems showed a trend towards being increased, which promoted wound healing. However, after mechanical wounding, the ratio of stress- to growth-promoting hormones first increased and then decreased. This pattern can enhance stress resistance and promote cell division, respectively. Comprehensive analysis showed that the fluorescence parameter, photochemical quenching coefficient (Qp_Lss), was the most suitable indicator for evaluating mechanical wounding conditions.

Online diagnosis platform for tomato seedling diseases in greenhouse production

In modern facility agriculture, to improve the quality and efficiency of transplanting, the application of transplanting robots based on visual processing is becoming more and more widespread. In order to reduce the damage to plants during the transplanting process and reduce the damage rate of plant stems, leaves and substrates, a transplanting method based on Kinect visual processing combined with an inclined transplanting manipulator was proposed. In the research, the Kinect visual processing was used to obtain and process the seedling height information and leaf edge information, and the working coordinate system of the transplanting manipulator was established and applied to plan the obstacle avoidance path. Combined with the oblique manipulator, the obstacle avoidance transplanting method was proposed. Through the structural design and force analysis of the seedling transplanting device, the key parameters that affect the transplanting quality were obtained, and the optimal transplanting performance parameters were obtained through experiments. In the experiment, with the aid of the Kinect vision processing system, the designed obstacle avoidance transplanting manipulator had a leaf damage degree of 4.70%, a stem bending rate of 16.67%, substrate integrity of 83.45% and a transplanting quality parameter of 87.36%. The time for a single seedling transplanting was (8.32±0.40) s. The experiment result proves that the obstacle avoidance transplanting method based on Kinect visual processing can effectively reduce the damage to seedlings when ensuring the transplanting efficiency. Keywords: Kinect vision processing, oblique-type transplanting robot, path planning, obstacle avoidance DOI: 10.25165/j.ijabe.20211405.6451 Citation: Jin X, Li R S, Ji J T, Yuan Y W, Li M Y. Obstacle avoidance transplanting method based on Kinect visual processing. Int J Agric & Biol Eng, 2021; 14(5): 72–78.

Development of a PVDF sensor for potted seedling clamping force of vegetable transplanting