Chapter 22: General recommendations for the use of
Contents
1. end marker 2 Drying of samples It is important that samples are dried to absolute dry weight DW i e 0 moisture The DW refers to the sample weight reached after drying in a well ventilated forced draft oven Figure 22 1A at 60 75 C until constant weight typically for at least 48h see Table 22 1 When drying samples e Do not mix fresh samples with dry samples e Organize sampling to optimize use of the oven and of oven space e Use anon draft oven for drying open container samples e g soil moisture samples Figure 22 1B 126 Physiological Breeding II A Field Guide to Wheat Phenotyping for specific information modes measurement data download etc further details and clarification Do not use an instrument before it has equilibrated with ambient temperature and relative humidity RH as this may affect the calibration and data Take the instrument out of its protective case and turn on at least 10 minutes before Starting use Do not leave an instrument in direct sunlight heat before use as this can affect calibration and may cause incorrect readings especially for instruments with black cases When reading air temperature and RH stand with your back to the sun so as not to expose the instrument to direct sun during measurements Do not operate an instrument outside specified temperature and RH range for the instrument as measurements taken may be incorrect check the user guide for speci2. It is essential to select the type of balance according to the capacity and resolution demanded Table 22 2 Figure 22 2 It is often observed that samples are weighed on inappropriate balances e g weighing stems from the partitioning of 20 culms on a large precision balance rather than a small precision balance When weighing samples e Do not weigh hot samples direct from the oven allow time for sample to cool to room temperature before weighing to avoid incorrect readings and or causing damage to the balance Table 22 2 Recommendations for the type of balance and minimum resolution required for the determination of sample weight of various sample types Typical Minimum Sample weight g Type of balance resolution g 2 m plot grain weight FW gt 1000 Industrial retail bench 5 2 m plot biomass FW gt 1000 Industrial retail bench 5 100 culm sub sample FW 500 Large precision 1 100 culm sub sample DW 200 Medium precision 1 Sub sample grain weight 50 Small precision 0 1 Soil moisture of 100 g 30 Small precision 0 1 20 culm stem biomass DW 20 Small precision 0 01 200 grain FW and DW 10 Small precision 0 01 Leaf samples for RWC lt 2 Semi analytical 0 001 Root biomass of 100g lt 2 Semi analytical 0 001 Where FW fresh weight DW dry weight RWC relative water content General recommendations 127 e Do not allow time for samples to absorb moisture e Note that individual container weights may vary after oven
3. as a guideline and will vary according to accessories functionalities taxes and customs fees Table 22 5 provides details of suggested models of instruments Reference to specific instruments is made in most chapters The mention of trade names and commercial products are for information purposes only and do not Table 22 5 Suggested models of instruments websites accessed August 2011 Instrument Brand Model s Measurement level Website Ceptometer Delta T Devices SunScan System and SS1 Canopy htto www delta t co uk Decagon Devices AccuPAR LP 80 Canopy http www decagon com Chlorophyll Opti Sciences OS1 FL and OS 30p Leaf htto www optisci com fluorometer Qubit Systems Z990 FluorPen Leaf http www qubitsystems com WALZ PAM 2500 MINI PAM Leaf http www walz com Hansatech Intruments FMS 2 Pocket PEA Leaf http www hansatech instruments com Chlorophyll meter Minolta SPAD 502 Plus Leaf http www specmeters com Field Scout CM 1000 Canopy http www specmeters com Opti Sciences CCM 200 Leaf http www optisci com Hansatech Intruments CL 01 Leaf http www hansatech instruments com Apogee CCM 200 Leaf http www apogeeinstruments com FT Green LLC At Leaf Leaf http www atleaf com Qubit Systems Z955 Nitrogen Pen Leaf http www qubitsystems com Infrared Sixth Sense LT300 Canopy htto www instrumart com thermometer Mikron MI N14 Canopy htto www mikroninfrared com
4. Chapter 22 General recommendations for the use of instruments Julian Pietragalla and Alistair Pask 1 Correct use of instruments Instructions may vary according to the make and model of your instrument Refer the instrument user manual Do ensure that the operator is familiar with each instrument functionality correct approach to take data and expected readings before going into the field it is worth receiving advice and training from an experienced user and reading the user guide Do take measurements consistently this is very important In particular ensure that the instrument is calibrated correctly before and sometimes again during use Keep a careful eye on the data during measurement to guard against erroneous data and large variations within a plot Do maintain batteries of correct type size and polarity Recharge batteries fully before use note that this may require overnight charging Take spare batteries to the field to ensure that measurements are not interrupted Do ensure to take the whole repetition with the same instrument If more than one instrument is available cross compare between instruments to check that they are giving similar data Do always make data easy to interpret process at a later date For example when taking readings with a data logger which records only basic information at the end of each section take two blank readings without a sample in the sensor chamber as an
5. Extech 42540 Canopy htto www extech com instruments Leaf area meter Licor LI 3100C and LI 3000C Leaf http www licor com CID Bio Science Cl 202 and Cl 203 Leaf http www cid inc com Delta T Devices WinDIAS 3 Leaf htto www delta t co uk Leaf porometer Delta T Devices AP4 Leaf htto www delta t co uk Decagon Devices SC 1 Leaf htto www decagon com Normalized difference NTech Industries GreenSeeker Hand Held Canopy htto www greenseeker com vegetation index Holland Scientific Crop Circle Handheld Canopy http www hollandscientific com NDVI Sensor Field Scout CM 1000 NDVI Canopy http www specmeters com Qubit Systems Z950 NDVI Leaf http www qubitsystems com Photosynthesis LI COR 6400 XT Leaf plant http www licor com system PP Systems CIRAS 2 Leaf plant http www ppsystems com CID Bio Science Cl 340 Leaf http www cid inc com WALZ GFS 3000 Leaf htto www walz com ADC LCpro SD Leaf htto www adc co uk Plot combine Wintersteiger Classic Plot htto www wintersteiger com Almaco PMC 20 SPC 20 Plot htto www almaco com Sample mill Grinder UDY Corporation Cyclone Grain biomass http www udyone com IKA MF 10 1 Grain biomass htto www ika net FOSS Cyclotec 1093 Grain biomass htto www foss dk Thomas Wiley Model 4 and Mini Grain biomass http www thomassci com Scholander pressure Soil moisture 3000 Series and 3005 Series Leaf htto www soilmoisture com chamber Equipment Corp Skye SKPM 1405 50 Leaf htto www
6. cted from the 1 000 Kilogram kg gross weight to give the sample weight This is typically il Meter m m Gram g appropriate for samples gt 20 g 0 01 Centimeter cm To do this 0 001 Millimeter mm Milligram mg e Select an empty container which is otherwise identical to that of the samples i e from the same box packet vai Table 22 4 Typical units of data expression with the same ventilation holes staples if any etc l l Sample Measured as Expressed as e Dry the empty container in the oven next to samples cinviei and aplot sorta for the same drying time biomass weights e Before weighing samples place this empty container Dry weight of culms and crop g per 20 culm g m or g culmi on the balance and press RE ZERO TARE components e g leaf sub sample e The balance should show zero with the empty lamina leaf sheath stem container on the balance plate or a negative value Root biomass g g soil g cm soil when the empty container is removed and the plate is empty 0 000 e B p B small precision 2 d p WwW ___ ao o ame Figure 22 2 Types of balances for physiological measurements showing A semi analytical C medium large precision 1 d p and D Industrial retail bench balances 0 d p 128 Physiological Breeding Il A Field Guide to Wheat Phenotyping 5 Suggestions on models of instruments imply endorsement by CIMMYT Prices quoted serve
7. drying Once dried samples tend towards slightly Ensure to select a good representative ambient humidity over time this may be from hours TARE container to days depending on the RH and type of sample An alternative to using a TARE container is to i e Samples for precision weighing may be kept ina subtract the average DW weight of the containers desiccator after drying only appropriate for use 10 empty containers to do this or ii to weigh small quantities individual containers as for the aluminum pots in the e Distribute the weight of the sample evenly across the determination of soil moisture content this volume balance plate Chapter 17 e For small samples lt 20 g carefully empty the sample from the container i e the bag envelope etc into 4 Typical ranges and units a specific weighing container and remember to It is recommended to keep all measurements in the subtract the container weight from the total weight same unit system typically on the decimal scale e For samples gt 20 g keep the sample in its container to REAA ane a avoid losses and remember to TARE the container weight Table 22 3 Useful units of measurement Removing the container weight by using a TARE Multiple Area length Weight When weighing samples in containers e g a bag 1 000 000 s Ton t envelope tube etc remember to first TARE this weight 10 000 Hectare ha so that the weight of this container is dedu
8. fications Excess heat and moisture RH may cause permanent damage note that instruments are typically not water resistant Do not discard instruments after use Remember to clean the instrument return it to its protective case and to the equipment store room It is important that each instrument is stored clean dry dust free and in the correct protective case Do not discard malfunctioning instruments when anomalies or problems have been noted during equipment use Repairs and or recalibrations to instruments may be required which may involve returning the instrument to the factory specialist This could take weeks or months Set dryer temperature and time depending on the type of sample estimated moisture content and capacity of the dryer Table 22 1 General drying temperatures and times for dry weight determination Note that drying time may differ according oven drying capacity Material Temperature C Time hours Relative leaf water content 60 75 24 Grain moisture 60 75 24 48 Biomass maturity 60 75 48 Root biomass 60 75 48 Biomass emergence to grain filling 60 75 48 72 Soil moisture gravimetric 105 48 Note that seed which potentially may be used for future trials should not be oven dried as drying seed at temperatures gt 40 C and or for long periods of time reduces their viability Notes for drying samples for nutrient and or metabolite analysis e Dry biomass samples at 60 75 C for N P K and
9. skyeinstruments com PMS Instrument Company Model 600 Leaf http www pmsinstrument com Seed counter Seedburo 801 Count A Pak Grain http www seedburo com automatic Pfeuffer CONTADOR Grain http www pfeuffer com Seed counter manual Seedburo Placement Trays Grain sample htto www seedburo com Soil corer set electric Eijkelkamp Agrisearch Percussion drilling set with Soil root http www eijkelkamp com percussion hammer Equipment light electrical percussion hammer Soil corer tractor Giddings Soil Sampling Co 15 Soil root http www soilsample com mounted Spectrometer Spectral Evolution PSR 2500 Canopy leaf http www spectralevolution com Ocean Optics JAZ Canopy leaf http www oceanoptics com PP Systems UniSpec SC and UniSpec DC Canopy leaf http www ppsystems com CID Bio Science Cl 700 leaf clip ready Leaf http www cid inc com Spectroradiometer ASD Inc FieldSpec 3 AgriSpec and Canopy leaf http www asdi com HandHeld 2 Spectral Evolution PSR 2500 and PSR 1100 Canopy leaf htto www spectralevolution com Thresher Almaco SBT and LPT Plot bundle sample htto www almaco com Vapor pressure EliTech Group Wescor VAPRO 5600 Tissue sap htto www wescor com osmometer General recommendations 129
10. water soluble carbohydrate determination e High drying temperatures gt 90 C for long periods may affect the nutrient content Some specific metabolites analyses e g enzymes proteins etc require freeze drying of samples or heat drying at a precise temperature and duration Ensure to check the specific procedural requirements of the laboratory Figure 22 1 Drying ovens A large capacity forced draft oven and B small capacity non draft oven suitable for drying open container samples e g soil moisture samples 3 Accurate weighing of samples It is essential that accurate weights are recorded for sampled material Poor weighing technique and or incorrect use of the balance will cause significant data errors either consistent e g due to not removing the bag TARE weight or random e g due to irregularly cooled oven dried samples Note that all balances are sensitive to changes in the environment and that laboratory balances both precision and analytical are more sensitive than field scales i e battery powered bench balance or spring mechanical scale Follow manufacturer s instructions for installation and e Keep level use inbuilt spirit level e Keep ona stable non vibrating surface e g a concrete plinth e Avoid areas near heaters ovens or air conditioners e Avoid direct sun and air flows e Avoid sharing power circuits with high consumption items e g a Microwave oven
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