Key points of using Canopy Sensors

Transcription

1 SWIM - Sustainable Water Integrated Management Demonstration Project Key points of using Canopy Sensors Greenseeker 505 Handheld (NTech Industries, Inc.) NDVI SPAD-502Plus (Konica Minolta) Chlorophyll content Infrared Thermometer INF151 (UEI) Canopy temperature Visual Senescence Scoring Stay-green 1

2 (Zadoks scale) Chlorophyll Content F v /F m Canopy Temperature NDVI Senescence Greenseeker 505 HandHeld 1. When to measure? 2. Equipment a) Mechanical Specifications b) Components & Accessories 3. Measurements a) Preparation b) Trial Measurements 4. Data Download & Processing 5. Common Problems & Solutions 2

3 GreenSeeker - NDVI Any time of the day. Plant surfaces must be dry and not wet from dew. Avoid windy days. Wind can modify canopy structure. Early vigor: 5, 10 and 15 days after emergence. Biotic and abiotic stress detection: measurements before, during and after stress. Biomass and crop growth rate: periodic measurements from emergence to end of anthesis. Senescence: weekly or every 3 to 4 days measurements from anthesis to maturity. a) Mechanical Specifications - Weight Unit 6 kg. - Weight of Unit, case and accessories 17 kg. - Case dimensions 35.5 x 35.5 x cm. - Over long distances should be transported in its box b) Components & Accessories - GreenSeeker V AC battery charger Charging Keeping the unit plugged when not in use will extend Charged the battery life. - Control Box Battery, circuit board to interface power and switches to the sensor and external connectors. Power Switch/ Indicator External Data port (RS232 Collection of data) Power connector 3

4 b) Components & Accessories Pocket PC displays and stores the data from the sensor. Should always be charged if not the collected data will be erased. NTech Capture pre-loaded software to capture the readings from GreenSeeker Handheld Sensor, display the current reading, and store for later data analysis or to make fertilizer recommendations. Pocket PC Pocket PC Cradle Trigger Switch (small buzzer) Extension pole DB9 (RS232) serial cable b) Components & Accessories - Sensor head Takes the reflectance readings Active - Internal illumination Shoulder Strap Sensor Head Sensor mount Pocket PC Extension pole Control box Pask A, Pietragalla J, Mullan D, Reynolds M (2012) Physiological breeding II: A field guide to wheat phenotyping. CIMMYT, Mexico 12 pin connector 4

5 a) Preparation 1. Fully charge batteries of Pocket PC & Sensor Unit - Usually > 6h (over-night). 2. Check connections - Sensor head, control box, extension pole and Pocket PC. 3. Check sensor head position to the crop - Horizontally positioned in relation to the ground - Adjust the distance to the canopy (string with a weight helps), by adjusting the sensor head angle and the extension pole. 4. Adjust shoulder straps - Place the strap diagonally across the body. b) Trial measurements 1. Turn on the Control Box and the Pocket PC. Allow 10 min to equilibrate with ambient temperature. If Unidentified USB Device error message appears on the Pocket PC display write: ftdi_ser.dll and press OK. 2. On the Pocket PC: 2.1. Go to Start > Programs and run NTechCapture software; 2.2. Select Sensor > Start GreenSeeker and select Logging Plots. 3. Position the Sensor at the start of the plot. Press and hold the trigger and traverse the region (speed 1 m s -1 ). Release the trigger. Data is recorded to the file. 4. When completed the data collection, go to File > Save assign file name. Display NDVI: last NDVI point recorded for the plot AVG NDVI: average NDVI of all points measured for the plot Sample: number of measured plots 5

6 Problem: Unidentified USB Device error message appears on the Pocket PC display after turning it on: Solution: write ftdi_ser.dll : 6

7 When data is saved three comma-delimited ASCII text files are created in the Pocket PC internal memory or removable memory card in My Device\My Documents\NtechCapture: - filename.txt all data collected. NDVI, Vegetation Index (VI = Red/NIR) values for each plot ( 10 values/ sec); - filenameavg.txt average NDVI and VI for each plot; - filenamediag.txt diagnostic information for the sensor. Note: Once the software is closed you cannot open a created file. After saving a data file, a new file can be created by tapping File > New. This will clear the data cells and allow the collection of new readings. Download files to the computer: Connect PDF to the USB-port and copy files from My Computer/ Mobile device to the computer (ActiveSync must be installed in the computer). Open files in MS Excel: 1. Launch Excel and select Open from the File menu. 2. Change File Types to All Files and select the.txt data file. 3. Select Delimited Text, delimited by commas and spaces. This will import data into separate columns in the spreadsheet file. 7

8 Problem Unidentified USB Device error message appears on the Pocket PC display after turning it on. Large variance in data. Variable reflectance values and/or with high error variance. Unintentional value recorded. Solution Write: ftdi_ser.dll and press OK. GreenSeeker sensor not held centrally over plot and/ or small plots large border effect. Low battery causing decreasing light source intensity affecting reflectance value. Charge unit. Take note of plot number and delete value during processing. GreenSeeker does not log data. Pocket PC errors or hangs. Not all counts are recorded. Battery does not charge. Check connections and cable between Pocket PC and Control Box. If connections and cable are fine, reset Pocket PC (press & hold power button select reset). (e.g. gate not available ). Reset Pocket PC. General file without all counts. Usually a problem with the cable. Battery charger light does not come on. Unit battery not charging. Probably broken fuse. Open Control Box and replace fuse. SPAD-502Plus 1. When to measure? 2. Equipment 3. Measurements a) Preparation b) Trial Measurements 4. Common Problems & Solutions 5. Maintenance (Reading Checker) 8

9 SPAD Chlorophyll Content No restrictions on time of the day and environmental conditions. Leaf surface should be dry. Biotic and abiotic stress detection: measurements before, during and after stress. Peak chlorophyll: measurements should be done early in the season, heading and mid-grain filling. Senescence: weekly or every 3 to 4 days measurements from anthesis to maturity. SPAD-502Plus (Konica Minolta) Chlorophyll meter Measuring Head Measurement Centre Line Receptor Window Sliding Depth Stop Display Average Button Finger rest Power Switch Data Recall Button All Data Clear Button 1 Data Delete Button Battery Chamber Cover (2 AA batteries) 9

10 a) Preparation 1. Measuring chamber should be clean and the rubber seal intact. 2. Turn SPAD on and allow 10 min to equilibrate with the ambient temperature. b) Trial Measurements 1. Calibration (always after turning on) - With no sample close measuring head until beep. - SPAD is calibrated. Battery indicator b) Trial Measurements 2. Calibration Errors - Series of beeps measuring head was not completed closed during calibration or was opened before calibration was finished. Repeat calibration keeping measuring head completely closed until calibration is finished. - Series of beeps measuring head emitting and/ or receiving windows may be dirty. Clean and repeat calibration. 10

11 b) Trial Measurements 3. Measurement 3.1. Adjust siding Depth Stop Place the leaf in the sensor: - Measuring area 2 mm x 3 mm up to 1.2 mm thick; - 1/3 to 1/2 of the way to the leaf base; - Adaxial surface facing upwards; - Avoid midrib, major veins & thick parts of the leaf Close measuring head until beep Reading displays in the screen. b) Trial Measurements 3. Measurement 3.5. Repeat 3.1. to 3.4 up to N=5 (SPAD can store up to 4096 values or 1488 with GPS) Review readings (and graphic trend): - Press Data Recall button; - Remove outliers and retake measurements if needed Press Average button and record average value Press All Data Clear button twice (go to next plot start from 1.). 3. Measurement Errors Series of beeps and ERROR message while measuring: - Measured head was not closed completely or was opened before the measurement was completed. - Sample is too thick or thin. - Repeat measurement with head completely closed. 11

12 Problem Solution SPAD not giving readings but emitting beeps when closed. Large variation in SPAD values within a plot. Damage to the surface of the crop (e.g. frost, disease, etc.). Chamber and/ or chamber seal is dirty or leaf not positioned correctly. Retake reading. Maintain consistent point of measurement along the leaf. Lower values might be associated with the leaf being: damaged, diseased or leaf tip has been inserted. Healthy and clean leaves should be used. Do not use SPAD in dead material and avoid damaged areas of the crop. 1. Turn ON while pressing 1 DATA DELETE and DATA RECAL. 2. Calibrate 5. Check Average Average value should be within the range of the Reading Checker. If not clean emitting and receiving windows and repeat. If it is still not within the range, there is a possible malfunctioning contact service centre. Turn Off and On to resume normal operation. 4. Insert Reading Checker & Measure up to N=5 3. Remove Depth Stop 12

13 Infrared Thermometer INF151 (UEI) 1. When to measure? 2. Equipment 3. Measurements a) Preparation b) Trial Measurements 4. Common Problems & Solutions IRT Canopy Temperature Clear sky with little or no wind - measurements should be taken between 11:00am to 2:00pm. Days with high temperatures (> 25 C) and VPD work preferably. Leaf surface should be dry. Biotic and abiotic stress detection: measurements before, during and after stress. Senescence: weekly or every 3 to 4 days measurements from anthesis to maturity. 13

14 Infrared Thermometer INF151 (UEI) Canopy temperature IR Sensor Laser Pointer Bean Trigger (ON/ Measurement Button) Handle Battery (9V) compartment LCD Display Units Button ( F and C) Emissivity Button (0.95, 0.90, 0.85) Back Light Button (ON/ OFF) Laser Button (ON/ OFF) Infrared Thermometer INF151 (UEI) Canopy temperature Wrong Right Distance to scanned area ratio 8:1 14

15 Pen Type Hygrometer DTH10 (UEI) Temperature and Humidity meter Hold Button ON/ OFF Button MIN/ MAX Button Sensor Temp (F/C) (Change unit from F to C) Reset Button (CR2032 battery) a) Preparation 1. Turn on the temperature/ humidity meter. Allow the instrument to equilibrate with the ambient temperature (± 3 min), not exposing directly to sun. Record air temperature and relative humidity (RH). 2. Turn on infrared thermometer by pressing the trigger and check if emissivity is set to If not press Emissivity Button while pressing the trigger until 0.95 emissivity is chosen. Allow IRT to equilibrate with the ambient temperature for 10 min. b) Trial Measurements 1. Point the IRT to the plot and press the trigger - record reading (releasing the trigger activates the 7 second auto-hold). A minimum of 3 measurements per 6 m 2 plots is advised, for 1 m 2 plots one measurement is sufficient. Record the ambient temperature and RH at the start of each plot measurement. 2. Advises: - Take measurements of the part of the plot most exposed to the Sun; - Avoid the shadow of the operator; - The thermometer distance and angle should be constant; - If readings of the same plot differ > 1 C, repeat measurements. 15

16 a) Trial Measurements 3. Angle and position of the thermometer determines the Spot. Pask A, Pietragalla J, Mullan D, Reynolds M (2012) Physiological breeding II: A field guide to wheat phenotyping. CIMMYT, Mexico Problem Initial canopy temperature values higher/ lower than on the rest of the trial. Readings in the same plot differ by > 1 C. Solution IRT did not sufficient equilibrate with ambient temperature. Let IRT to equilibrate for at least 10 min with the ambient temperature. Check that IRT is being held correctly and consistently throughout measurements. Avoid borders, damaged/ senesced leaves, soil, etc.. 16

17 1. Methods/ Equipment 2. Calculations Visual Senescence Scoring Methods/ Equipment: To be performed on flag-leaves and repeated weekly or 3 to 4 days from anthesis to physiological maturity. 1. Make a general observation by standing at 45 angle to plot. 2. Randomly select and mark 5 (or more) shoots and attribute scores to each individual flag-leaf. Visual Senescence Scoring Stay-green 17

18 Fitting the senescence data score = p0 + p1 x (1 exp(( -p2 x STA/ p1)) + (10 p1 p0/ (1 + exp(-4 x p3 (STA p4)/ (10 p1 p0))) Score: visual senescence score STA: thermal time after anthesis ( C days) p0: score at anthesis p1: score at the end of the slow phase p2: maximum rate of the slow phase p3: maximum rate at rapid phase (Sen Rate ) p4: date at which p3 is reached Sen Onset : onset of senescing phase date. Stay-green associated with Sen Onset and Sen Rate