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Traditional orchard production is facing problems of labor shortage due to the aging, difficulties in the management of agricultural equipment and production materials, and low production efficiency which can be expected to be solved by building a smart orchard that integrates technologies of Internet of Things(IoT), big data, equipment intelligence, et al. In this study, based on the objectives of full mechanization and intelligent management, a smart orchard was built in Pinggu district, an important peaches and pears fruit producing area of Beijing. The orchard covers an aera of more than 30 hm2 in Xiying village, Yukou town. In the orchard, more than 10 kinds of information acquisition sensors for pests, diseases, water, fertilizers and medicines are applied, 28 kinds of agricultural machineries with intelligent technical support are equipped. The key technologies used include: intelligent information acquisition system, integrated water and fertilizer management system and intelligent pest management system. The intelligent operation equipment system includes: unmanned lawn mower, intelligent anti-freeze machine, trenching and fertilizer machine, automatic driving crawler, intelligent profiling variable sprayer, six-rotor branch-to-target drone, multi-functional picking platform and finishing and pruning machine, etc. At the same time, an intelligent management platform has been built in the smart orchard. The comparison results showed that, smart orchard production can reduce labor costs by more than 50%, save pesticide dosage by 30% ~ 40%, fertilizer dosage by 25% ~ 35%, irrigation water consumption by 60% ~ 70%, and comprehensive economic benefits increased by 32.5%. The popularization and application of smart orchards will further promote China's fruit production level and facilitate the development of smart agriculture in China.

BACKGROUND: The use of unmanned aerial vehicles (UAVs) for the application of plant protection products (PPPs) in paddy fields is becoming increasingly prevalent worldwide. Despite its growing usage, UAV spraying for rice pest control faces practical challenges, including limited canopy penetration, uneven deposition, and significant spray drift. This study investigated the impact of two tank‐mix adjuvants, Wonderful Rosin (Adjuvant‐1) and Tiandun (Adjuvant‐2), at six volume concentrations, on the spray liquid's physicochemical properties, spray drift, plant deposition, and the biological efficacy of rice insecticides using a quadrotor UAV sprayer. RESULTS: The physicochemical characteristics of the spray liquid influenced spray performance and biological efficacy. Incorporating Adjuvant‐1 and Adjuvant‐2 led to a decrease in surface tension and contact angle while increasing the viscosity of the spray solution. These alterations in surface tension and viscosity contributed to an optimized droplet size distribution, reduced spray drift, enhanced deposition uniformity and penetration, and improved control efficacy against the rice planthopper in UAV applications. The highest control efficacy was observed at a concentration of 0.5%, showing an improvement of 35.12% (Adjuvant‐1) and 20.23% (Adjuvant‐2) over applications without tank‐mix adjuvant 7 days after treatment. CONCLUSION: The judicious selection of tank‐mix adjuvants for UAV PPP applications can significantly enhance spray performance and biological efficacy in controlling rice insects. This study's findings offer valuable insights for integrating tank‐mix adjuvants into UAV spraying applications. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: The unmanned aerial spraying systems (UASS) have gained widespread use for plant protection in recent years. However, spray drift from UASS is a major concern when controlling weeds over large areas and warrants a thorough investigation. This study examined the atomization characteristics of the herbicide florpyrauxifen‐benzyl under downwash airflow using a UASS spray test platform. Potential spray drift was assessed using a test bench (TB) and airborne drift collectors (ADCs) in the field under low wind speeds (<1 m s−1). RESULTS: Atomization characteristics were significantly affected by the spray liquid, adjuvant, nozzle type and spray pressure. The addition of an adjuvant reduced the liquid sheet length, improved physicochemical properties and increased droplet size under the downwash airflow field. Drift evaluation in the field using the TB revealed that sediment spray drift predominantly occurred from the middle to the entire length of the device when fine‐to‐medium droplets were produced after the sprayer passed. ADC assessment found that higher flight altitudes and finer droplets resulted in higher drift values, whereas the addition of an adjuvant and the use of an air‐induction nozzle reduced drift <3 m aboveground. CONCLUSION: The combination of using TB in the target area and ADCs in the off‐target area as an alternative method to determine residual droplets in the current airflow provided valuable insights into airborne drift assessment for UASS. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

To demonstrate the feasibility and improve the implementation of laser weeding, a static movable lift-adjustable closed fiber laser weeding device and system have been developed, followed by experiments and performance evaluations. Physical experiments were conducted on the energy required for laser cutting of weed stems, targeting four common larger weeds (Chenopodium album, Amaranthus spinosus, Setaria viridis, and Eleusine indica) in farmland and orchards. At the same irradiation distances, the energy required to cut the same type of large weed generally increases with increasing distances and stem diameters but decreases with increasing irradiation time. The variance of stems' power density after irradiation was larger and the values were more dispersed for Chenopodium album and Setaria viridis weeds, and the values were relatively scattered, while the power density values of Amaranthus spinosus and Eleusine indica weeds were more concentrated. When the irradiation time was 10 s, the 3.892 W/mm2 laser was sufficient to eliminate weeds and plants with the irradiation distances of 2 m. The 2.47 W/mm2 laser was more effective, as it killed weeds within a distance of 1 m in less than 1 s. This work demonstrates the feasibility of the laser weeding device and system that can completely cut off the stems of large weeds, and this technology has the potential to promote sustainable agriculture. [ABSTRACT FROM AUTHOR]

Pesticide application using UAV sprayer has become a new highlight in the development of agricultural machinery and plant protection in China. Spray droplets from UAV could reach the crop canopy and deposit on the control target surface under the assistance of rotor's downwash airflow after atomization, including a secondary atomization effect of airflow on the droplets, so the spray performance of aerial pesticide application is inseparable from the effect of the rotor's downwash airflow field. In order to explore the effect of downwash airflow field on UAV's spray deposition characteristics, taking the main model of eight-rotor UAV with "X-type" as the research object and designing the actual measuring test, a multi-channel micro-meteorology measurement system(MMMS) was used to determine the downwash airflow speed at different horizontal positions, and meanwhile the tracer Allura Red solution was applied instead of chemicals to obtain the distribution characteristics of spray deposition. The visual analysis of the measured results of the downwash airflow field distribution was focused, and then the distribution characteristics of both the downwash airflow field and the droplet deposition at a certain flight height and speed, and the correlation relationship between them were analyzed. During the flight operation of the 8-rotor UAV, as the flight speed increased from 1.0 to 6.0 m/s and the flight height increased from 1 to 2 m, the intensity of the downwash airflow field in directions of X, Y, and Z generally changed from strong to weak, and the distribution state changed from concentration to dispersion; the X direction airflow was the vortex generated by the interaction between the downwash airflow and the outside air and its effect on droplets was reversed flight direction; the airflow in Y direction was to the both sides from flight path, caused by the combination of downwash airflow and ground effect; the airflow in Z direction, the vertical downward component of the downwash airflow, had a direct promotion effect on spray deposition. Significant negative correlations were shown between both the flying speed and the peak value in the range of the downwash airflow field (P 0), that was, the stronger the downwash airflow field in the vertical ground direction, the more droplets deposited in the effective spray swath. When the flight speed increased to 6.0 m/s, the wind speed was significantly reduced, and the promotion effect of the downwash airflow field on the droplet deposition disappeared(P> 0.05). The operation speed of UAV should not be set faster than 6.0 m/s to avoid the chemicals loss caused by the weakened effect of the downwash airflow field. The findings of this study are expected to provide theoretical basis and data support for improving the quality of low-altitude and low-volume application operations and the formulation of UAV field operations specifications.

Solar energy, a pivotal renewable resource, faces operational challenges due to its intermittent and unstable power output. Thermal energy storage systems emerge as a promising solution, with phase change materials (PCMs) packed beds attracting attention for their compactness and stable temperature transitions. This paper details a laboratory-scale solar thermal storage PCM packed bed integrated with a heat pump, utilizing a novel form-stable PCM. A numerical model was established to assess the thermal storage characteristics and heat extraction performance of the solar PCM packed bed coupled with a heat pump. Simulation results show that increasing solar irradiance significantly reduces storage duration, achieving full thermal storage in 3.4 h at 900 W/m2 irradiance. Optimal starting times were identified as 9:00 a.m. or 11:00 a.m., with later starts resulting in incomplete storage due to the PCM not reaching its phase change temperature. Additionally, packed bed parameters influenced storage conditions; increasing the paraffin content in the PCM extended the phase change duration, while graphene nanoparticles slightly reduced it. Lower porosity (0.49) beds, with higher PCM content, reached 70 °C quicker than higher porosity (0.61) beds due to higher pressure drops promoting more uniform flow and temperature distribution. During heat extraction, coupling the heat pump at 2 liters/min achieved temperatures below 45 °C in 4.1 h, while at 6 liters/min, the time reduced to 1.6 h, demonstrating adaptability to different extraction rates. These findings provide insight into the thermal performance of solar PCM packed beds coupled with heat pumps, contributing to efficient and stable thermal utilization of solar energy. [ABSTRACT FROM AUTHOR]

BACKGROUND: Over the past decade, unmanned aerial vehicle (UAV) sprayers have emerged as valuable tools for pesticide application across various crops. Despite their increasing usage, the impact of several factors on spray performance and control efficacy in paddy fields warrants further investigation. This study examines atomization characteristics using a UAV spray test platform. Our evaluation of field spraying performance considers three UAV models, two nozzle types, two flight velocities, and adding methylated vegetable oil adjuvant (MVOA), in comparison with the electrical knapsack sprayer (EKS). RESULTS: Atomization characteristics demonstrated consistency within the downwash airflow field, but were influenced by spray solution, nozzle type, and spray pressure. The eight‐rotor UAV sprayer excelled over the quad‐rotor model in terms of spray deposition across both upper and lower rice canopies. The six‐rotor UAV exhibited enhanced spray deposition, droplet density, and coverage at a flight velocity of 4 m s−1. The choice of nozzle was pivotal; the flat fan nozzle produced finer droplets with desirable deposition and coverage, whereas the air‐induction nozzle created larger droplets with consistent coverage at various flight velocities. Adding MVOA improved the physicochemical properties of the spray and its performance, yielding a more uniform distribution. When compared with the EKS, UAVs showed lower deposition but comparable spray penetration. Control efficacy with the UAV sprayer was less effective against Mythimna separata but achieved 81% efficacy against Laodelphax striatellus within 7 days. CONCLUSION: This study demonstrates that UAV sprayers, particularly when combined with tank‐mix adjuvants and nozzle types, can be highly effective for controlling rice pests. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

To overcome drought stress in soybean (Glycine max), it is strategically vital to improve drought resistance. Yet, the underlying molecular mechanisms responsible for drought resistance remain poorly defined. Here, we present comparative physiological and transcriptome analyses in seedlings of two contrasting genotypes, drought‐resistant (DR) L14 and drought‐sensitive (DS) L21 in response to polyethylene glycol (PEG)‐induced drought stress. Each genotype was subjected to 20% PEG along with control (0% PEG) in a greenhouse, and the leave samples were collected to determine the physiological traits and transcriptome profiling. With the accumulation of abscisic acid (ABA) under drought stress, the DR genotype exhibited higher water retention capability and slow‐wilting phenotype compared to DS genotype. As nonsignificant changes in oxidative damages and antioxidant defenses, overcoming drought stress in DR genotype was facilitated by drought avoidance rather than drought tolerance. There were 1567 and 4029 differentially expressed genes (DEGs) identified in the DR and DS genotypes, respectively. The DEGs were mostly enriched in photosynthesis, carbohydrate metabolism, lipid metabolism, cell wall organization, and signaling pathways, which were less affected in DR genotype. However, most of the leucine‐rich repeat receptor‐like kinases (LRR‐RLKs) were uniquely downregulated in DS genotype but uniquely upregulated in DR genotype by drought stress. By protein–protein interaction network analysis and whole genome resequencing, six LRR‐RLKs were considered the potential candidate genes for drought avoidance. We suggested that these LRR‐RLKs may play a critical role in promoting ABA‐induced stomatal closure through enhancing ABA sensitivity, but this hypothesis needs further validation. Taken together, these findings could provide in‐depth insights into the physiological and molecular mechanisms associated with drought avoidance and facilitate the breeding of drought‐resistant soybean cultivars. Core Ideas: The L14 had higher water retention capability and slow‐wilting phenotype compared to L21 under drought stress.The differentially expressed genes (DEGs) associated with several metabolisms were more affected by drought stress in L21 rather than L14.Six leucine‐rich repeat receptor‐like kinases (LRR‐RLKs) genes would be considered potential candidates for drought resistance but need further validation. [ABSTRACT FROM AUTHOR]

Background: Droplets of plant production products sprayed from unmanned aerial spraying system (UASS) applications are prone to drift, threatening nontarget crops, humans, and environment. There are few studies that have investigated plant bioassay of UASS spray drift, and even fewer when it comes to herbicide application. This work reports a combined field‐scale evaluation of spray drift and plant bioassay for a rice herbicide florpyrauxifen‐benzyl application using a six‐rotor motor UASS under acceptable operating conditions. An artificial rice canopy was built to simulate a practical field application scenario and the soybean was applied to assess the nontargeted crop injury. The effects of nozzle type (droplet size), flight height, and adjuvant on spray deposition, sedimenting drift, airborne drift, and soybean injury were studied to explore the feasibility of UASS herbicide application. Results: Under an average wind speed of 1.2–1.5 m s−1, reduced flight height, increased droplet size, and adding nonionic surfactant resulted in greater deposition, lower drift, and less injury to soybean. Increasing droplet size by changing the nozzle was more effective compared with adding adjuvant and reducing the flight height, which offers greater flexibility and can accomplish better spray performance. The correlations between sedimenting drift and soybean injury percentage were highly significant (P < 0.01, r > 0.96). The calculated buffer distances of 7.7–18.9 m were to varying degrees less than the soybean safety distances of 10.0–20.0 m. Conclusion: The results of this study provide a reference basis for determining optimum working parameters and establishing buffer zones for the rice herbicide application of UASS. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]