• Journal of the Korean Society for Nondestructive Testing
• /
• v.23 no.3
• /
• pp.198-204
• /
• 2003

A basic experiment was performed to control tile plant growth using acoustic emission technique considering the environmental conditions for plant. At a dry soil condition, the signals due to the cavitation from xylem of angiosperm and gymnosperm were mainly detected. The strong signal from xylem and the weak signal from plasmodesmata and casparian strip were detected at the same time after distilled water was provided. Two signals after providing tile acid and distilled water were contrary to each other. The wind, number of leaf, music, temperature and humidity affected the acoustic emission count from plants but the frequency ranges of the detected signals were the same.

• Journal of Bio-Environment Control
• /
• v.29 no.1
• /
• pp.28-35
• /
• 2020

This study is to compare irrigation efficiency between sap flow sensor automated system (SF) and conventional irrigation system based on integrated solar radiation automated system (ISR) in tomato rockwool hydroponics. Total irrigated volumes was higher in the ISR system by 5.0L per plant, a lower drainage rate was found in the SF system, compared to the ISR system. There was no difference in shoot and fruit fresh weights, water use efficiency (WUE) and water amount consumed for producing 200g of tomato fruit. The daily average sap flow density (SFD) was closer to the change of solar irradiance (SI) in the plant grown under the SF system, compared to the ISR system. The correlation coefficient (r²) between the fruit diameter and the volumetric water content during the 56 and 82 days after transplant showed the SF treatment was higher than the ISR at night and daytime, and the correlation was higher at night time. The sap flow density and humidity deficit (HD) of SF treatment was related as closely as the solar irradiance. Further studies should demonstrate that SF irrigation system is a convenient method for hydroponic farmers with advantages, such as growth, higher yield, WUE, and accuracy.

• Journal of Bio-Environment Control
• /
• v.28 no.4
• /
• pp.366-375
• /
• 2019

This experiment aims to determine the proper irrigation scheduling based on a whole-substrate capacitance using a newly developed device (SCMD) by comparing with the integrated solar radiation automated irrigation system (ISR) and sap flow sensor automated irrigation system (SF) for the cultivation of tomato (Solanum lycopersicum L. 'Hoyong' 'Super Doterang') during spring to winter season. For the SCMD system, irrigation was conducted every 10 minutes after the first irrigation was started until the first run-off was occurred, of which the substrate capacitance was considered to be 100%. When the capacitance threshold (CT) was reached to the target point, irrigation was re-conducted. After that, when the target drain volume (TDV) was occurred, the irrigation stopped. The irrigation volume per event for the SCMD was set to 50, 75, or 100 mL at CT 0.9 and TDV 100 mL during the spring to summer cultivation, and the CT was set to 0.65, 0.75, 0.80, or 0.90 in the winter cultivation. When the irrigation volume per event was set to 50, 75, or 100 mL, the irrigation frequency in a day was 39, 29, and 19, respectively, and the drain rate was 3.04, 9.25, and 20.18%, respectively. When the CT was set to 0.65, 0.75, or 0.90 in winter, the irrigation frequency was about 6, 7, 15 times, respectively and the drain rate was 9.9, 10.8, 35.3% respectively. The signal of stem sap flow at the beginning of irrigation starting time did not correspond to that of solar irradiance when the irrigation volume per event was set to 50 or 75 mL, compared to that of 100 mL. In winter cultivation, the stem sap flow rate and substrate volumetric water content at the CT 0.65 treatment were very low, while they were very high at CT 0.90 was high. All the integrated data suggest that the proper range of irrigation volume per event is from 75 to 100 mL under at CT 0.9 and TDV 100 mL during the spring to summer cultivation, and the proper CT seems to be higher than 0.75 and lower than 0.90 under at 75 mL of the irrigation volume per event and TDV 70 mL during the winter cultivation. It is going to be necessary to investigate the relationship between capacitance value and substrate volumetric water content by determining the correction coefficient.

• 한국가시화정보학회:학술대회논문집
• /
• 2003.11a
• /
• pp.83-86
• /
• 2003

Synchrotron X-ray micro imaging technique was employed to non-invasively monitor the water flow inside xylem vessels in a bamboo leaf. The phase contrast X-ray images clearly visualized plant anatomy and the rise of a water front inside the vessels. Consecutive X-ray images taken for 60 seconds revealed water rise kinetics against gravity in the xylem of a cut dry leaf taken from a bamboo tree. For the first time, traces of water rise, variation of contact angle between water and xylem wall as well as the internal structure of xylem were obtained. In xylem vessels, a repeating flow pattern has a typical flow velocity of $30.7{\mu}m/s$ and faster flow is established intermittently. It is concluded that the transmission type of X-ray micro imaging can be used as a powerful tool to investigate the ascent of sap in the xylem vessels at a resolution higher than that of MRI.

• Journal of the Korean Society of Visualization
• /
• v.8 no.4
• /
• pp.48-53
• /
• 2010

Water-uptake through roots, is an essential process of the water flow in plants. Its visualization is very useful for understanding sap flow dynamics at whole plant level. In this study, the tips of Arabidopsis' root hairs were excised and exposed to repeated dehydration and rehydration processes. The water-refilling through individual xylem vessels was visualized using the synchrotron X-ray micro-imaging technique. The high temporal resolution ($2\;{\mu}m$) and beam intensity of the X-ray source allowed to acquisition of consecutive X-ray images of the water-refilling process up to 10 frames/sec. Various flow patterns were observed and the ascending speed of the water-air interfaces was analyzed. The relation between the water-rising height and ascending speed was also analyzed. The present results would provide better alternative for investigating sap flows in roots.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.1693-1696
• /
• 2004

Synchrotron X-ray micro-imaging technique was employed to monitor non-invasively the refilling process of water inside the xylem vessels in bamboo leaves. The consecutive phase-contrast X-ray images clearly show both plant anatomy and the transport of water inside the xylem vessels. Traces of water-rise, vapor bubbles and variations of contact angle between the water front and the xylem wall were measured in real time. During the refilling process, air bubbles are removed when the rising water front halts at a vessel end for a while. Subsequently, it starts rising again at a higher velocity than the normal refilling speed. Repeated cavitation seems to deteriorate the refilling ability in xylem vessels. In dark environment, the water refilling process in xylem vessels is facilitated more effectively than in bright illuminated conditions. Finally, X-ray micro-imaging was famed to be a powerful, high resolution, real time imaging tool to investigate the water refilling process in xylem vessels.

• Korean journal of applied entomology
• /
• v.47 no.4
• /
• pp.369-378
• /
• 2008

After treatment with imidacloprid, there were clear differences in the time to the first reaction of Myzus persicae among the concentrations treated. The time taken for the proboscis of the aphids to penetrate, during the recording plants increased as the imidacloprid concentration increased. Imidacloprid concentration inflow into a leaf was investigated using high-performance liquid chromatography, and the residues of the imidacloprid varied slightly with the different concentrations treated. However, the inflow rates of this insecticide into a leaf increased as the dipping times increased. Furthermore, it was shown that there was no relationship in inflow concentration between the concentrations and times of treatment. However, the concentration in the leaf differed according to the dipping time. Judging from the fact that the first reaction behavior against imidacloprid displayed at an inflow concentration of 0.32-0.35 mg/L, we concluded that inflow concentrations causing the first reaction of the aphids to the insecticide were much lower than the concentration treated. The general feeding characteristics of the aphids indicated that xylem and/or phloem feeding behavior continued after a series of probing behaviors and stylet activity during the first 3 h from the start of EPG recording. After 90 min treatment with imidacloprid, feeding behavior over the next 30 min indicated a significant increase in the withdrawal of the stylet from the plant at all treated concentrations. Xylem and/or phloem feeding patterns were significantly decreased during this time. In particular, the proportion of xylem feeding differed according to the concentration of imidacloprid.

• Korean journal of applied entomology
• /
• v.55 no.4
• /
• pp.351-358
• /
• 2016

Consistent with a previous study on the brown planthopper Nilaparvata lugens (BPH) (Seo et al., 2009), we identified seven distinct EPG waveforms (np, L1, L2, L3, L4-a, L4-b, and L5) in adult female Laodelphax striatellus (SBPH) that fed on rice plants, by using the direct current electrical penetration graph (DC-EPG) system. The shape of waveforms and the pattern of occurrence of each waveform of SBPH were very similar to those of BPH. L3 and L4-a always occurred prior to L4-b. Periodical honeydew excretion was observed in L4-b only. Microsection observation following laser stylectomy revealed that the tips of SBPH stylets severed in L3, L4-a, and L4-b were commonly located in or near the phloem region of rice plants, but were located in the xylem in L5. Plant sap flowed from the stylets severed in L4-b only, and its main carbohydrate component was detected as sucrose by HPLC analysis. These results and the patterns of EPG waveform progress in SBPH suggested that feeding activities on rice plant tissue were relevant to each EPG waveform. L1 and L2 corresponded to the initiation of stylet penetration and stylet movement with salivation on the outside of the vascular bundle. L3 and L4-a were related to feeding activities within the phloem region in preparation for phloem sap ingestion. L4-b was closely associated with phloem sap ingestion, and L5 corresponded to xylem feeding behavior.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.11
• /
• pp.1612-1617
• /
• 2003

Synchrotron X-ray micro imaging technique was employed to non-invasively monitor the water flow inside xylem vessels in a bamboo leaf. The phase contrast X-ray images clearly visualized plant anatomy and the rise of a water front inside the vessels. Consecutive X-ray images taken for 60 seconds revealed water rise kinetics against gravity in the xylem of a cut dry leaf taken from a bamboo tree. For the first time, traces of water rise, variation of contact angle between water and xylem wall as well as the internal structure of xylem were obtained. In xylem vessels, a repeating flow pattern has a typical flow velocity of 30.7$\mu\textrm{m}$/s and faster flow is established intermittently. It is concluded that the transmission type of X-ray micro imaging can be used as a powerful tool to investigate the ascent of sap in the xylem vessels at a resolution higher than that of MRI.

• Korean journal of applied entomology
• /
• v.32 no.2
• /
• pp.208-217
• /
• 1993

Feeding behavior fo female brown planthoppers, Nilaparvata lugens Stal, was examined with an electrical recording technique using DC amplifier and through anatomical observation of stylet ovement in the rice plat with electrical recordings. There was six feeding patterns, type P, S, SB, O, X and Ph with the brown planthopper. Type P was a probing pattern during searching the proper feeding site. Type S appeared to be associated with the initial penetration and changing direction through the tissues, and from this type type SB pattern could be distinguished by the regularity of the large potential drops seen, and might be associated with penetration of the phloem sheath and/or salivation in the phloem sheath. The type O pattern shows none of the large voltage drops which were believed to occur when cell walls were being broken down and passes through a relatively thin layer of cells into an air space. The very constant waveform of the type X pattern could be seen during ingestion within the xylem bundle sheath area. The Ph pattern always followed an SB pattern and was associated with a marked negative voltage drop. When this pattern was seen, the brown planthopper might be ingested plant sap from phloem sheath area.