A light device for pre-harvest grape fruits and applications

Abstract

The application discloses a kind of preharvest grape fruit illumination device and its application, belong to fruit illumination technical field.The illumination device includes dark room and is located on the light source and environmental sensor of dark room inner wall, the dark room includes the frame of being set in the periphery of grape bunch and the light shield of being set on the frame, the bottom of the frame is equipped with exhaust fan, top is equipped with the through-hole for grape bunch to extend into and the fixing member for being fixedly connected with grape cultivation shed frame.The application uses dark room to carry out illumination treatment to single fruit, is conducive to the influence of quality formation that illumination acts on fruit itself is clearly distinguished;The light quality, light intensity of light source can be replaced according to illumination treatment needs, meet different illumination treatment needs;Exhaust fan is arranged at the bottom of dark room, ensure that the temperature and humidity of inside and outside of dark room are consistent;Environmental sensor can record the environmental parameter inside dark room in real time, provide basis for the specific parameter of illumination treatment, is conducive to subsequent data analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of fruit illumination, and in particular to an illumination device for pre-harvest grape fruits and an application thereof. Background Art

[0002] Plants are affected by a variety of external environmental factors during their growth and development. Among these environmental factors, light is one of the most important. It not only provides energy for the growth of plants at all stages, but also regulates the growth and development of plants.

[0003] Studies have shown that light is closely related to flower bud differentiation, floral organ development, physiological fruit drop, fruit yield, color, and quality. It is generally believed that light affects fruit quality mainly by affecting leaf photosynthesis and assimilate transport. However, recent studies have also shown that photosynthesis in the fruit itself can contribute 20% of the total assimilates in the fruit. Strengthening the abundance and function of chloroplasts in the fruit and manipulating their transformation into chromoplasts are effective ways to improve fruit quality. The prerequisite for achieving this path is a comprehensive understanding of the specific regulation of fruit chloroplast development (Acta Horticulturae Sinica, 2022, 49(12): 2669-2682.).

[0004] A bottleneck in conducting relevant research is the lack of devices for independent light treatment of fruit. Currently, these devices are primarily designed for post-harvest fruit, such as the light incubator for post-harvest fruit disclosed in patent document CN 218889056U. However, the research results obtained using this device fail to reflect the effects of light regulation on fruit growth and development.

[0005] On the other hand, current research on preharvest fruit light treatments typically uses monochromatic or mixed-color light to illuminate both the plant and the fruit. However, in reality, the light characteristics required for plant vegetative growth and fruit quality development differ. For example, plants primarily utilize red light for photosynthesis, while fruit color development is primarily sensitive to blue-violet light. Indiscriminate light treatments of both plant and fruit yield results that cannot eliminate the effects of light on vegetative tissues, hindering in-depth research on the impact of light regulation on fruit quality.

[0006] Therefore, developing a system for independent illumination of pre-harvest fruits is a problem that needs to be solved by those skilled in the art. The use of this system can help to clarify the optimal lighting conditions required for the formation of fruit quality independent of nutritional growth, provide hardware support for the in-depth development of related research, and provide guidance for actual production. Summary of the Invention

[0007] The purpose of this invention is to provide a system for independent illumination of pre-harvest grape berries, which only illuminates the berries, eliminating the effects of light on nutritional tissues, exploring the relationship between light regulation and fruit quality formation, providing hardware support for in-depth research, and also providing guidance for actual production.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] The present invention provides a lighting device for pre-harvest grapes, comprising a darkroom, a light source and an environmental sensor arranged on the inner wall of the darkroom. The darkroom comprises a frame sleeved around the periphery of the grape bunches and a light shield sleeved on the frame. An exhaust fan is provided at the bottom of the frame, and a through hole for the grape bunches to extend into and a fixing piece for fixing to a grape cultivation trellis is provided at the top.

[0010] The present invention eliminates the influence of natural light by setting up a darkroom around the grape fruits, and sets light sources with different light quality, light intensity and light period in the darkroom to provide different light environments for the grape fruits, so that the influence of different artificial light environments on the quality of the fruit can be observed. At the same time, an automatic switching ventilation fan is set at the ventilation hole to achieve air circulation inside and outside the darkroom, and the heat generated by the light source can be discharged outside the darkroom in time to stabilize the temperature in the darkroom. At the same time, environmental sensors such as light and temperature and humidity sensors are set in the darkroom to automatically record the light and temperature and humidity conditions in the darkroom, providing a basis for subsequent analysis of the environmental requirements of the fruit quality formation process.

[0011] Preferably, the frame is formed by a steel mesh and is cylindrical in shape. The steel mesh can ensure air circulation and ensure the normal development of the grapes.

[0012] Preferably, the light shield is made of black cloth with a light transmittance of less than 5%, and its shape is adapted to the frame to enclose it, forming a darkroom. Covering the frame, the light shield prevents ambient light from entering the processing device and prevents internal supplemental light from leaking out and affecting plant growth. Using black cloth to make the light shield not only blocks light but also ensures air circulation, ensuring the normal development of the grapes.

[0013] Preferably, ventilation holes are provided at the bottom of the light shield corresponding to the position of the exhaust fan.

[0014] Preferably, the top of the light shield is provided with an upwardly protruding cylindrical opening section at the position corresponding to the through hole of the frame, and a tightening cord is provided at the end of the opening; when the tightening cord is tightened, the opening section closes, forming a darkroom inside the light shield. This arrangement satisfies the darkroom conditions without damaging the fruit stems and fruit, and enables illumination treatment of a single fruit.

[0015] Preferably, the fixing member comprises a plurality of fixing ropes arranged at the top edge and evenly spaced along the circumference, with the free ends of the fixing ropes passing through the light shield. The length of the fixing ropes is adjustable, and the height of the device can be adjusted according to the surrounding conditions of the fruit to ensure that the fruit is in the middle of the dark chamber.

[0016] Preferably, the inner wall of the frame is provided with LED light strips arranged in a spiral from top to bottom. The present invention sets a linear light source on the inner wall of the darkroom and arranges it in a spiral on the inner wall, which is conducive to obtaining the same lighting environment for different parts of the fruit and improving the uniformity of the fruit quality.

[0017] The light source can be selected to have different light qualities, light intensities, and photoperiods as needed. In the present invention, a control system can be used to control the light source's operating photoperiod to meet various experimental requirements. Preferably, the light / dark ratio of the photoperiod is set to five conditions: 16h / 8h, 12h / 12h, 8h / 12h, constant light, and constant dark.

[0018] The lighting device provided by the present invention further includes a control system, which includes:

[0019] The environmental detection module is used to receive signals collected by the environmental sensor and send them to the processor module;

[0020] The light control module is used to receive and execute instructions sent by the processor module to control the operation of the light source;

[0021] The ventilation control module is used to receive and execute instructions sent by the processor module to control the operation of the exhaust fan;

[0022] The processor module is used to receive and process the data transmitted by the environment detection module and send work instructions to the light control module and the ventilation control module;

[0023] A display module, electrically connected to the processor module, for displaying the operating status of the device;

[0024] Power module, which provides power to various components and modules.

[0025] The environmental sensors include a light intensity sensor and a temperature and humidity sensor. The light intensity sensor is connected to the light intensity detection module via an interface; the temperature and humidity sensor is also connected to the temperature and humidity detection module via an interface. These sensors monitor the light intensity, temperature, and humidity in the darkroom in real time. The temperature, humidity, and light intensity data are stored in a storage module, which is connected to a computer and can be exported to provide environmental data for subsequent scientific analysis.

[0026] In the present invention, a preset program based on time can be written into the processor module through computer language. After the device is started, the system clock starts timing, and the control system works according to the preset program.

[0027] Preferably, the light control module is connected to the light source strip via an interface, and a relay is used to control the working time of the light source.

[0028] Preferably, the ventilation control module is connected to the exhaust fan via an interface and uses PWM to control the exhaust fan air volume. The exhaust fan is controlled by a PWM pulse width modulation signal generated by the processor module timer. This allows for different cooling air volumes to be adjusted during daytime and nighttime operation depending on the amount of sunlight. Furthermore, the fan emits different noise levels at different PWM duty cycles, facilitating later debugging.

[0029] Preferably, the display module adopts an OLED screen, which can display parameters such as the current time, temperature, humidity, light intensity, and control status.

[0030] Preferably, the power module is connected to a 220V to 12V switching power supply to supply power to various components of the device.

[0031] The present invention also provides a method for irradiating pre-harvest grapes using the device, comprising the following steps:

[0032] (1) Setting up the control program in the device control system based on computer language, the program content includes the control of the light source working time at the specified date and time, the timed ventilation of the equipment, the storage of data, the display of test results and the control of external interfaces;

[0033] (2) During the grape fruit development period, the grape bunch is inserted into the frame through the through hole at the top of the device, the device is hung and fixed on the steel wire of the grape cultivation trellis using a fixing piece, and then the light shield is sealed to form a dark room;

[0034] (3) Turn on the power to start the device, the control system starts the system clock and begins timing, and each component starts working according to the preset program.

[0035] Preferably, the device operates in a cyclic mode, and the light cycle of the light source processing is five optional modes: light / dark ratio 16h / 8h, 12h / 12h, 8h / 12h, constant light and constant dark; the exhaust fan starts and stops every 30 seconds; the data storage time interval is 3 hours.

[0036] The present invention has the following beneficial effects:

[0037] (1) The present invention uses a darkroom to perform light treatment on a single fruit, which can shield the influence of external ambient light on the quality formation of the fruit, and at the same time avoid the influence of light overflow in the darkroom on the growth and development of other parts of the plant, which is conducive to clearly distinguishing the influence of light on the quality formation of the fruit itself.

[0038] (2) The present invention sets the light source and the power supply independently, and the light quality and light intensity of the light source can be freely changed according to the needs of light treatment, thereby meeting the needs of different light treatments for fruits.

[0039] (3) The present invention sets an exhaust fan at the bottom of the darkroom and sets it to start automatically at a fixed time, which can effectively discharge heat and ensure that the temperature and humidity and other environmental conditions inside and outside the darkroom are consistent, which is beneficial to the growth, development and quality formation of the fruit.

[0040] (4) The present invention sets an environmental sensor inside the darkroom, which can record the environmental parameters such as light, temperature and humidity inside the darkroom in real time, providing a basis for clarifying the specific parameters of light treatment, which is conducive to subsequent data analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the structure of the device of the present invention.

[0042] Figure 2 It is a structural schematic diagram of the frame in the device of the present invention.

[0043] Figure 3 Schematic diagram of the bottom perspective structure of the device of the present invention.

[0044] Figure 4 This is a physical diagram of the control system in the device of the present invention.

[0045] Figure 5 This is the overall functional block diagram of the hardware of the environmental control and temperature, humidity and light intensity detection equipment of the device of the present invention.

[0046] Figure 6 The software design flow chart of the device of the present invention.

[0047] Figure 7 Flowchart of the data reading procedure of the device of the present invention.

[0048] Figure 8 This is a physical diagram of the application of the device of the present invention.

[0049] Figure 9 This is a curve chart showing the temperature changes after reading the temperature data in the memory.

[0050] Figure 10 This is a curve chart showing the changes after reading the humidity data in the memory.

[0051] Figure 11 The device of the present invention is used to analyze the properties of grape fruits after being treated with white light and blue light. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with specific examples. The following examples are only used to illustrate the present invention and are not intended to limit the scope of application of the present invention. Without departing from the spirit and essence of the present invention, modifications or replacements made to the inventive method, steps or conditions all fall within the scope of the present invention.

[0053] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the materials and reagents used are commercially available reagents and materials unless otherwise specified.

[0054] Example 1

[0055] This embodiment provides a system for independently illuminating pre-harvest grapes based on LED light sources, the system comprising a darkroom 1, a light source 2 and an environmental sensor 3 provided on the inner wall of the darkroom, and a control system 4 provided outside the darkroom. Figure 1-4 As shown, specifically:

[0056] Darkroom 1, a space for precise pre-harvest light treatment of the grapes, comprises a frame 11 that fits over the grape bunches and a light shield 12 that fits over the frame. Frame 11 is cylindrical and enclosed in a steel mesh. The use of the steel mesh ensures air circulation, ensuring the normal development of the grapes. Light shield 12, covering the outside of frame 11 and shaped to fit the frame, encloses it to form a darkroom. This prevents ambient light from entering the processing unit and prevents internal supplemental light from escaping and affecting the plants' nutritional growth. Made of black cloth with a light transmittance of less than 5%, light shielding ensures air circulation while protecting the grapes from light, ensuring their normal development.

[0057] The top of frame 11 is provided with a through-hole 111 for inserting grape bunches. A cylindrical opening protrudes upward from the top of light shield 12, corresponding to through-hole 111. A tightening cord 121 is attached to the end of the opening. Once a grape has entered frame 11, the cord 121 is tightened, closing the opening around the stem and sealing it, creating a darkroom within light shield 12. This arrangement allows for darkroom conditions without damaging the stem or fruit, enabling illumination of individual grapes.

[0058] The top of the frame 11 is also equipped with a fixture for connecting to the grape cultivation trellis. These fixtures consist of three fixed ropes 13, evenly spaced along the circumference of the top edge. The free ends of the ropes 13 pass through the light shield 12, suspending the device from the steel wires of the grape cultivation trellis. The length of the ropes 13 is adjustable, allowing the device's hanging height to be adjusted according to the surrounding conditions of the fruit, ensuring that the fruit is centered in the darkroom.

[0059] The inner wall of the frame 11 is provided with a linear LED light source 2, which is arranged in a spiral shape from top to bottom, so that different parts of the fruit in the dark room are evenly illuminated. The LED light source 2 can select different light qualities and light intensities according to needs.

[0060] The light source is controlled by a control system 4, and the light cycle light / dark ratio can be selected from five conditions: 16h / 8h, 12h / 12h, 8h / 12h, constant light and constant dark to meet various test requirements.

[0061] Environmental sensors 3 are provided on the inner wall of the frame 11, including light sensors and temperature and humidity sensors, which record the light intensity and temperature and humidity conditions in the darkroom in real time. The data can be recorded and exported through the control system 4 to confirm at any time whether the environment in the darkroom meets the conditions for fruit growth and provide environmental data for subsequent scientific analysis.

[0062] An exhaust fan 5 is provided at the bottom of the frame 11, and a ventilation hole is provided at the bottom of the light shield 12 corresponding to the position of the exhaust fan 5. The exhaust fan 5 is controlled by the control system 4 and automatically switches on and off at a fixed time to promote air circulation inside the device, exhaust the heat generated by the LED light strip, and ensure that the indoor and outdoor environments are consistent.

[0063] Each of these system components is controlled by a control system 4, which includes a processor module 41, a display module 42, a power module 43, an LED light control module 44, a temperature and humidity detection module 45, a light intensity detection module 46, and a ventilation control module 47. This control system primarily performs the following functions: 1. Powering the power supply, exhaust fan, light sensor, and temperature and humidity sensor; 2. Periodically recording the light intensity, temperature, and humidity within the darkroom; 3. Providing a computer interface for exporting recorded data; 4. Controlling the automatic on / off timing of the power supply and exhaust fan; and 5. Providing a human-machine interface and displaying the device's operating status.

[0064] The following combination Figure 4-5 The hardware design of the control system 4 in this embodiment is described.

[0065] The core of the control system 4 (processor module 41) is a 32-bit microcontroller STM32F103C6T6A based on ARM CORTEX-M3, and the development environment is KEIL MDK.

[0066] The display module 42 uses a 3.2-inch OLED screen, which can display the current time, temperature, humidity, light intensity, control status and other parameters.

[0067] The power supply of this system is provided by a 220V to 12V switching power supply, which is connected to the power module 43 through 431. The power module 43 supplies power to the CPU and other parts. The LED light control module 44 uses a relay to control the working time of the LED light strip, and is connected to the LED light strip light source 2 through interface 441. The light intensity sensor and the temperature and humidity sensor are connected to the temperature and humidity detection module 45 and the light intensity detection module 46 through interface 451. The temperature, humidity and light intensity data are stored in the 24C64 EEPROM, and a data is recorded every 3 hours. The stored data can be communicated with the computer through the USART2 port of the STM32F103C6T6A; the ventilation control module 47 uses PWM to control the air volume generated by the fan, and is connected to the exhaust fan 5 through interface 471 to maintain the stability of the temperature and humidity of the controlled environment.

[0068] The following combination Figure 6-7 The software design of the control system 4 in this embodiment is described.

[0069] Since the equipment needs to operate continuously in the field for more than 3 months, relevant operation control is required to be carried out based on time.

[0070] First, we need to implement date and time functions, including light source operating time control, equipment timed ventilation, data storage, test result display, and external interface control at a specified date and time. The display program displays the current operating status of the environmental control and detection instruments in real time, and regularly saves the current device's temperature, humidity, and light intensity data for later data processing.

[0071] The control program for the environmental control and detection equipment was designed based on KEIL MDK and C language. After starting the device, the CPU will start the system clock, initialize the GPIO port, sensor interface driver, fan PWM driver, and start the calendar clock to start timing.

[0072] The system works in a cyclic mode. First, the high and low levels of the 4-bit GPIO port are read to determine the preset LED working time, which is divided into multiple working modes of constant light, 16h, 12h, and 8h. The plants in the environment are illuminated by light, and the fan is started and stopped every 30 seconds to ensure that the temperature and humidity in the environment are consistent with the outside world. Secondly, the data storage interval is determined by converting the system's daily running time into minutes, which is 1440, and dividing it by the number of minutes in 3 hours, which is 180. When the remainder is 179, data is stored. It is not set to 0 because the data defaults to 0 when the system is turned on, which will cause the data to be stored when it is turned on. Finally, the ambient temperature, humidity and light intensity data are read and displayed on the OLED screen. The cycle is repeated.

[0073] This environmental control and temperature, humidity, and light intensity monitoring instrument communicates with a computer via USART1 on the CPU. The CPU uses TTL logic and the computer uses a USB interface. The CPU is connected to the computer via a CH341 TTL-to-USB module. To acquire data, we use AccessPort serial port monitoring software to send a receive command to the CPU. Upon receiving the string, the CPU interprets the command as a pre-defined command, reads the data from the 24C64, and sends it to the computer via DMA. For post-processing, the data can be directly copied to Excel.

[0074] Example 2

[0075] The blue-black grape variety 'Nan Taihu Te Zao' was treated using the device of Example 1. The treatment was completed in a simple plastic greenhouse using an H-shaped trellis cultivation mode.

[0076] Specifically, a 220V to 12V transformer is installed in the greenhouse to power the processing device, which is fixed on the iron wire on the frame surface. Each device processes one bunch of fruit. Figure 8 shown.

[0077] The device was installed on June 3, 2023, and two treatments were established. The light strips were installed as white and blue, respectively. Three devices were installed in each treatment, treating three fruit bunches. Each treatment served as a biological replicate. The photoperiod for all treatments was 16 h of light and 8 h of darkness. Treatments lasted until July 15.

[0078] After the treatment, the temperature and humidity records in the memory were read, and grape samples were taken to measure single fruit weight, firmness, TSS and anthocyanin content in the fruit skin.

[0079] Result analysis:

[0080] After the samples were collected, the temperature and humidity data in the memory were read respectively, and the data of the two devices were selected for plotting. The results are as follows: Figure 9 and Figure 10 As shown in the figure, the temperature and humidity in the treatment device show periodic changes, with higher temperatures during the day and lower temperatures at night. However, there are no obvious differences in temperature and humidity between different treatments / repetitions, indicating that the consistency of this device is good.

[0081] The single fruit weight of grape samples was measured, and the results showed that there was no significant difference in the single fruit weight between the white light treatment and the blue light treatment. The results of the soluble solids TSS measurement showed that the TSS content of the white light treatment fruit was significantly higher than that of the blue light treatment fruit. The results of the anthocyanin content measurement showed that the anthocyanin content of the white light treatment fruit was significantly higher than that of the blue light treatment fruit. The results of the fruit firmness measurement showed that there was no significant difference between the white light treatment and the blue light treatment ( Figure 11 ).

[0082] The research results showed that the TSS and anthocyanin contents of the fruits in the white light treatment group were higher than those in the blue light treatment group. This may be because the red light in white light can be used by chloroplasts to synthesize sugar, thereby significantly increasing the sugar content of the fruit. Sugar is an important precursor substance for the accumulation of anthocyanins, so the anthocyanin content is also higher.

[0083] This device, for the first time, achieves independent light treatment of fruit without affecting the surrounding vegetative organs. Under these treatment conditions, differences in fruit quality are due to the effects of light on the fruit itself, rather than the vegetative organs. This distinguishes between light regulation of fruit quality through vegetative organs and direct light regulation, providing technical support for further research on the effects of light regulation on fruit quality.

Claims

1. A method for irradiating pre-harvest grape berries using an illumination device to explore the relationship between light regulation and fruit quality formation, characterized in that: The lighting device includes a darkroom, a light source, and an environmental sensor located on the inner wall of the darkroom. The darkroom includes a frame that fits around the grape bunches and a light shield mounted on the frame. The frame is cylindrical and made of wire mesh. The light shield is made of black cloth with a light transmittance of less than 5% while ensuring air circulation. Its shape matches the frame and surrounds it to form a darkroom. The inner wall of the frame is provided with an LED light strip arranged in a spiral from top to bottom. The device operates in a cyclic mode, with the light source providing five optional light / dark cycles: 16h / 8h, 12h / 12h, 8h / 12h, and constant light and constant dark. An exhaust fan is located at the bottom of the frame, and a through hole for the grape bunches to enter and a fixing member for fixing to the grape cultivation trellis is located at the top. The lighting device further includes a control system, which includes: The environmental detection module is used to receive signals collected by environmental sensors and send them to the processor module; the environmental sensors include light intensity sensors and temperature and humidity sensors; The light control module is used to receive and execute instructions sent by the processor module to control the operation of the light source; the light control module is connected to the light strip through an interface and uses a relay to control the working time of the light source; The ventilation control module is used to receive and execute instructions sent by the processor module to control the operation of the exhaust fan; the ventilation control module is connected to the exhaust fan through an interface and uses PWM to control the air volume of the exhaust fan; The processor module is used to receive and process the data transmitted by the environment detection module and send work instructions to the light control module and the ventilation control module; A display module, electrically connected to the processor module, for displaying the operating status of the device; The power module is connected to the 220V to 12V switching power supply to supply power to various components and modules; The method comprises the following steps: (1) Setting up the control program in the device control system based on computer language. The program content includes the control of the light source working time at the specified date and time, the ventilation processing of the equipment at a fixed time, the exhaust fan starting and stopping every 30 seconds, data storage, detection result display and external interface control; (2) During the grape fruit development period, the grape bunch is inserted into the frame through the through hole at the top of the device, the device is hung and fixed on the steel wire of the grape cultivation trellis using a fixing piece, and then the light shield is sealed to form a dark room; (3) Turn on the power to start the device, the control system starts the system clock and begins timing, and each component starts working according to the preset program.

2. The method according to claim 1, wherein A cylindrical opening section protruding upward is provided at the top of the light shield corresponding to the through hole of the frame, and a tightening rope is provided at the opening end; when the tightening rope is tightened, a dark room is formed inside the light shield.

3. The method according to claim 1, wherein The fixing member comprises a plurality of fixing ropes which are arranged on the top edge and are evenly distributed along the circumferential direction, and the free ends of the fixing ropes pass through the sunshade.

4. The method according to claim 1, wherein The device operates continuously for more than 3 months, and the data storage interval is 3 hours.

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