Checking the leaves Dry leaf tissue and plant sap analysis compared Jan Hardeman Account Manager Horticulture
Eurofins Agro The Netherlands Wageningen Lab facility +/- 250 employees +/- 600.000 samples/year Naaldwijk Office in World Horti Center 4 employees PlantDoctor + Fertilization specialists
Greenhouse growing system 1. Water source 2. Fertilisers 3. Drip water 4. Plant material 5. Growing media 6. Drain water 7. Water purification 8. Disinfector
Composition of plants o Plants o 90% water o 10% others 90% C and O 10% Macro and micro elements Water Other Organic (C, O) o So 99% of a crop is C, O und H 2 O o And 1% macro and micro elements BUT too less: deficiency problems Macro and micro elements
Amount of nutrients in leaf tissue
Why leaf analysis? o Substrate, soil and drain water analysis will show: Availability of nutrients around the roots! But does not guarantee the uptake by the crop!
Stemphylium and K in onion leaves Stemphylium (% infection 10th August) 16 14 12 10 8 6 4 2 0 R² = 0,8796 0 kg K2O/ha 100 kg K2O/ha 200 kg K2O/ha 400 kg K2O/ha 0 5 10 15 20 25 30 35 40 K in leaves (g/kg dry matter)
Nutrient uptake by the crop o Depends on: Mulder s Chart ph EC Climate conditions (temperature, light, humidity) Physical composition of the substrate/soil Presence of micro organisms Antagonism and synergism between elements
ph and nutrient availability
Example substrate analysis raspberry o High: o K o Low: o Mg o Fe o Mn o Zn
Example Crop Check analysis raspberry o High: o K o Low: o Mg o Fe o Mn o Zn
2 types of leaf analysis 1) Dry leaf tissue analysis (analysis of total nutrients: dissolved nutrients + nutrients in organic compounds (like cell walls, proteins, chlorophyll, enzymes etc.)) 2) Plant sap analysis (analysis of dissolved nutrients in sap flow and cellular fluid)
Sap flow and cellular fluid o Xylem: from roots to leaves (water and nutrients with ph +/- 5.5) o Phloem: from leaves to roots (assimilates and nutrients with ph +/- 8.0) o Cellular fluid
Forces to transport nutrients o In xylem by: o Root pressure, transpiration and capillary action o In phloem by: o Osmotic flow by differences in sucrose concentration (from source (leaves) to sink (shoot tops, fruits, roots))
1) Dry leaf tissue analysis (Crop Check) o Washing materials (Teepol) o Drying at 70 ºC (dry matter 105 ºC) o Extracted using HNO 3 method o International method (a lot of literature) o Used for > 25 years o Dry matter, N-total, K, Na, Cl, Ca, Mg, P, S Fe, Zn, Mn, Cu, B, Mo + Al o Analyse time: 3 days o A large database with targets at Eurofins Agro! N-total with NIR
2) Plant sap analysis (Plant sap Check) o Freeze plant material o Defreeze o Squeeze/press o Filter o Analyse o ph, EC, NH₄, K, Na, Ca, Mg, NO₃, Cl, S, P, Fe, Mn, Zn, B, Cu, Mo, Si + Al o Analyse time: 2 days Will also destroy plant cells so soluble nutrients in vacuole are analysed too
Ca in strawberry leaves Dry leaf tissue (Crop check) Plant sap check Sap in phloem and xylem 482 mmol/kg DM 22 mmol/l sap = 120 mmol/kg DM? (sampling very difficult)
Elements in dry matter vs sap o For easily soluble nutrients like K, Na, Cl and NO₃: more or less linear correlation between 2 analysis methods o Big differences between the 2 methods for Ca, Mg, P, N-total and some micro nutrients (elements which are part of plant tissue structures)
K in dry matter and sap K laminea y=0.918x + 62.0 K petioles y=1.057x + 19.1 K concentration of tomato tissues (Plant nutrition of greenhouse crops, 2009)
Ca in dry matter and sap o A lot of Ca in cell walls this part not possible to analyze in plant sap Ca concentration of carnation leaves (Plant nutrition of greenhouse crops, 2009)
Calcium o Distribution of Ca within the plant strongly effected by transpiration (so via xylem). o Plant parts with large evaporation surface (leaves) mainly supplied by xylem more Ca o Plant parts with low evaporation surface (fruits) mainly supplied by phloem less Ca Old leaves with a long evaporation time will have higher Ca level than young leaves
Mobility of nutrients in the phloem o Very less Ca translocation via phloem (Marschner s Mineral Nutrition of Higher Plants, 2012)
K and Ca in blueberry in mmol/kg DM Leaves Fruits Calcium (Ca) 130 10 Potassium (K) 160 120 Enough to get good quality fruits with a long shelf life?
Sampling o Nutrient composition of plant material depends on: o Plant species o Plant age o Growing stage (vegetative, generative) o Time of day o Time of season o Plant part
Sampling Decide the aim of analyzing: 1. Monitoring a healthy crop a) Fruit bearing crops: take young full grown leaves (for complete overview check also older leaves). For sap analysis: take a sample at full turgor (early in the morning) b) Take a representative sample from different places (>20 spots) c) Around 200 grams fresh material (fruits around 500 grams) d) Use plant parts without dew or rain on the surface e) Avoid evaporation during transport (closed plastic bags)
Sampling 2. Checking nutrient disorders: a) Take plant parts with deficiency or excess symptoms (if present: take also a sample from a crop without symptoms) b) Follow same procedure b) to d) from monitoring a healthy crop c) Choose always the dry leaf tissue analysis (Crop Check)
Summary o Dry leaf tissue analysis: Shows all nutrients accumulated during the lifetime of a leaf (more robust method) o Plant sap analysis: Shows the dynamics of nutrient uptake in the sap flow and cellular fluid (snapshot in time)
Conclusion o Get certainty by checking also plant material! Check what you give (Drip water check) Check the availability around the roots (Soil check and Drain water check) Check the leaves (Crop check and Plant sap check) + fruits!!!
o Nutrient uptake by combination of dry leaf tissue + plant sap analysis o Cell wall analysis in plant material (lignin, cellulose, hemicellulose) will show lignin amount in the leaves a correlation with insect o Developments Eurofins Agro infestation or shelf life of the fruits? Soil life analyses (PLFA technique) o Quality organic matter Score insects 10 8 6 4 2 0 0 200 400 Lignine
Sending samples made simple o Coming soon: website www.sending-samples.com
Thank you for your attention! Jan Hardeman Account Manager Horticulture Email: JanHardeman@eurofins.com Telephone: +31 (0) 6 52002168