The monitoring and control of environmental conditions are crucial as they influence crop quality and yield in Chinese solar greenhouses (CSGs). The objectives of this study were to assess the spatial, temporal, and vertical variability of major environmental parameters in CSGs during winter and to provide greenhouse climate/microclimate characteristics in order to facilitate the monitoring and control of greenhouse environmental conditions. A wireless sensor network (WSN) was deployed in two CSGs: one with crops and one without. Sensors were placed at different locations inside and outside the greenhouses, and the air temperature, humidity, CO₂ concentration, light intensity, solar radiation, and wind conditions were measured and analyzed. Significant variability in the spatial, temporal, and vertical distribution of environmental factors was observed in both greenhouses. The average minimum and maximum temperatures and humidity inside the CSG with crops were 9.96 °C (4:00 h) and 24.5 °C (12:00 h), and 32.6% (12:00 h) and 92.1% (5:00 h), respectively. The temperature difference was 2.2 °C between layers in the CSG without crops and 1.4 °C between layers in the CSG with crops. The CO₂ concentration in the different layers inside the CSG with crops was highest at night. The average maximum light intensity inside the CSG with crops was 32,660.19 lx, 36,618.12 lx, and 40,660.48 lx (12:00 h to 13:00 h) in the bottom, middle, and top layers, respectively. Sensor positioning in the greenhouse was evaluated by considering the sensors’ data variability. The findings of this study could aid in the development of a better monitoring and control system for CSG’s microclimate during winter. More research is needed on greenhouse microclimate control systems based on this variability analysis, which could improve crop quality and yield in greenhouses.

Controlling humidity inside greenhouses is crucial for optimum plant growth and controlling physiological disorders and diseases. The humidity response and uniformity depend extensively on the evaluation of the dehumidifier. The objective of this research was to evaluate a low-powered suspension-type dehumidifier module in terms of humidity changes and spatial and vertical variability in a closed chamber and in a small greenhouse. A wireless sensor network including 27 sensor nodes was used to collect the data during the humidity changes from 80% to 70% and 90% to 70%. The humidity response results showed that the times required for dehumidification from 80% to 70% and 90% to 70% were 13.75 and 21.51 min, respectively, for the closed-chamber operation. Similarly, for the small greenhouse, 18 and 35 min were required to reduce the humidity levels from 80% to 70% and 90% to 70%, respectively. The spatial and variability results indicated that the changes in humidity at the rear and bottom layers were slower than those in the other layers of both experimental areas. The findings of this study would aid in the development of dehumidification strategies and sustainable agriculture for monitoring and controlling humidity in greenhouses using low-powered dehumidifiers.

Yield monitoring systems have become integral to precision agriculture, providing insights into the spatial variability of crop yield and playing an important role in modern harvesting technology. This paper aims to review current research trends in yield monitoring systems, specifically designed for non-grain crops, including cabbages, radishes, potatoes, and tomatoes. A systematic literature survey was conducted to evaluate the performance of various monitoring methods for non-grain crop yields. This study also assesses both mass-and volume-based yield monitoring systems to provide precise evaluations of agricultural productivity. Integrating load cell technology enables precise mass flow rate measurements and cumulative weighing, offering an accurate representation of crop yields, and the incorporation of image-based analysis enhances the overall system accuracy by facilitating volumetric flow rate calculations and refined volume estimations. Mass flow methods, including weighing, force impact, and radiometric approaches, have demonstrated impressive results, with some measurement error levels below 5%. Volume flow methods, including paddle wheel and optical methodologies, yielded error levels below 3%. Signal processing and correction measures also play a crucial role in achieving accurate yield estimations. Moreover, the selection of sensing approach, sensor layout, and mounting significantly influence the performance of monitoring systems for specific crops.

Considering Korea’s gradual shift toward an aging society, consumer interest in compounds with physiological benefits, including antioxidant and anticancer effects, has surged. This study explored the potential of Tetragonia tetragonoides (Pall.) Kunze, commonly known as New Zealand Spinach (NZS), a halophyte with reported health benefits, including efficacy in treating gastrointestinal diseases, high blood pressure, diabetes, and obesity. This study also introduced a novel callus culture system for NZS, allowing for the rapid in vitro production of secondary metabolites. Optimal callus induction (100%) and biomass production (0.416 g) were achieved by adding 2.0 mg·L⁻¹ 6-BA (6-Benzylaminopurine) and 0.5 mg·L⁻¹ 2,4-D (2,4-Dichlorophenoxyacetic acid) among five auxin and cytokinin combinations. Two distinct callus types, TGC [TDZ (Thidiazuron)-supplemented Green Callus] and TNYC [TDZ + NAA (Naphthalene acetic acid)-supplemented Yellow Callus], were identified, each with unique characteristics. The calli showed total phenolic and flavonoid contents comparable to those of NZS leaves grown in the greenhouse. An expression analysis of six genes (CHS, CHI, F3H, F3′H, FLS, and DFR) involved in the kaempferol biosynthesis revealed an enhanced flavonoid biosynthesis-related gene expression in TGC, emphasizing its potential for compound production. GC-MS analysis identified distinct compound profiles in TGC and TNYC, with 2,3-butanediol and succinic acid being the predominant compounds among the nine and forty-four components, respectively. These calli offer a stable supply of functional compounds and present an environmentally sustainable solution. The derived callus culture system is anticipated to contribute to the development of healthy functional foods or pharmaceuticals from halophyte NZS.

In greenhouse management, maintaining optimal humidity is essential for promoting plant growth, including photosynthesis, and preventing diseases and pests. Addressing spatial variability requires sensor-based monitoring for informed decisions on humidification systems, particularly for small, and suspension-type dehumidifiers. This study aims to assess the impact of various layouts of small-sized suspension-type dehumidifiers on vertical, spatial, and temporal humidity variability, along with energy consumption in a greenhouse. During experiments in a 648 m³ (18 m × 6 m × 6 m) plastic greenhouse, dehumidifiers were placed at four different layouts: one at the center (Layout 1), one on each side (Layout 2), two units at the center facing opposite directions (Layout 3), and two units on one side facing the center (Layout 4). Temperature and humidity (TH) sensors were connected to a microcontroller, facilitating wireless data acquisition, storage, and remote monitoring. The actuator was controlled through a relay module, and current sensors monitored power consumption. Spatial interpolation and mapping were employed using mapping software. These layouts reduced humidity from 89.30% to 51.10%, with Layout 2 displaying the most consistent humidity distribution. Water removal efficiency varied among layouts, with Layout 2 exhibiting the highest (61.15 L) and overall performance of 50%, while Layouts 1, 3, and 4 exhibited lower efficiencies of 40%, 44%, and 49%, respectively. Power consumption ranged from 0.506 to 0.528 kW for the dehumidifier and 0.242 to 0.264 kW for the fan. The findings highlighted that positioning the dehumidifier on both sides, facing towards the center (Layout 2), resulted in the most uniform humidity control within the greenhouse. The optimal layout of small suspension-type dehumidifiers in greenhouses would significantly improve humidity control, promoting plant growth.

Site-specific measurements of the crop yield during harvesting are essential for successfully implementing precision management techniques. This study aimed to estimate the mass of radish tubers using the impact principle under simulated vibration and sloped-field harvesting conditions with a laboratory test bench. These conditions included the conveyor speed (CS), impact plate layout (IP), falling height onto the impact plate (FH), the plate angle relative to the horizontal (PH), the field slope, and the vibration of the harvesting machine. Two layouts of impact-type sensors were fabricated and tested, one with a single load cell (SL) and the other with two load cells (DL). An adjustable slope platform and a vibration table equipped with vibration blades were utilized to simulate the slope and vibration effects, respectively. Calibrations were conducted to verify the accuracy of the sensor outputs, processed with the finite impulse response and moving average filters. Radish mass was estimated using an asymmetrically trimmed mean method. The relative percentage error (RE), standard error (SE), coefficient of determination (R²), and analysis of variance (ANOVA) were used to assess the impact plate performance. The results indicated that the SE for both impact plates was less than 4 g in the absence of vibration and slope conditions. The R² for the single and double impact plates ranged from 0.58 to 0.89 and 0.69 to 0.81, respectively. The FH had no significant impact, while the PH significantly affected the mass measurements for both impact plates. On the other hand, the CS significantly affected the plate performance, except for the double-load-cell impact plate. Both vibration and slope affected the mass measurements, with RE values of 9.89% and 13.92%, respectively. The RE for filtered radish signals was reduced from 9.13% to 5.42%. The tests demonstrated the feasibility of utilizing the impact principle to assess the mass of radishes, opening up possibilities for the development of yield-monitoring systems for crops harvested in a similar manner.