Reading Water, Media and Tissue Tests

1. Reading Water, Media and Tissue Tests Bodie V. Pennisi Extension Floriculture Specialist, UGA

2. What Do You Do If Your Pansies Look Like These?

3. Investigate: • Nutritional ? • Which nutrient(s) ? • Deficiency or toxicity ? • Cause(s) ?

4. Macronutrient-Related Problems

5. N Def: lower leaf yellowing (courtesy of Dr. Whipker, NCSU)

6. N Def: Lower leaf yellowing and loss (courtesy of Dr. Whipker, NCSU)

7. P Def: Lower leaf purpling (courtesy of Dr. Whipker, NCSU)

8. N Overdose: Upper leaf roll (courtesy of Dr. Whipker, NCSU)

9. High Nutrient Concentration in the Medium Causes Marginal Leaf Burn Water leaves the leaves via stomates, but the trace elements cannot escape. The effect is most pronounced at leaf margins where air movement causes the greatest evaporation.

10. Micronutrient-Related Problems

11. Mg Def: Lower leaves with interveinal chlorosis

12. Problems Mg Def: Lower leaves with interveinal chlorosis (courtesy of Dr. Whipker, NCSU)

13. Fe Def: Upper leaves with interveinal chlorosis

14. It Is All About the pH… At high pH the micronutrients (Fe, Mn, B, Zn, Cu) become less available. At low pH, they become too available.

15. Media pH is affected by: • lime incorporated • water alkalinity and pH • type of fertilizer used (basic or acidic) • species grown

16. Crops Can Be Placed Into Groups • Geranium Group • Plants that are very efficient in taking up Fe • Ex: seed and zonal geraniums, marygolds, New Guinea impatiens, lisianthus • Petunia Group • Plants that are very inefficient in taking up Fe • Ex: petunias, pansies, snapdragons, calibrachoa, vinca

18. Low pH

19. Geranium with chlorotic lower leaves which quickly turn necrotic (courtesy of Dr. Whipker, NCSU)

20. Lower leaves of pepper with black speckles (courtesy of Dr. Whipker, NCSU)

21. Lower leaves of marigold with yellow speckles (courtesy of Dr. Whipker, NCSU)

22. Lower leaves of cosmos with black speckles (courtesy of Dr. Whipker, NCSU)

23. High pH

24. (courtesy of Dr. Whipker, NCSU) Upper leaves with interveinal chlorosis

25. (courtesy of Dr. Whipker, NCSU) Upper leaves with interveinal chlorosis

26. (courtesy of Dr. Whipker, NCSU) Upper leaves with interveinal chlorosis

27. The Goal Is To Achieve A Stable Medium pH Over Time

28. Basic Tests • Concentration of the fertilizer solution • pH and soluble salts in the growing medium • Leaf tissue analysis • Water Quality

29. Testing the growing medium • EC (SS) and pH of the leachate • In-house tests can be done with the pour-through method • Sending samples to a lab: do not use the top 1/2 to 1 inch of the soil • NO3--N, NH4+-N, P, K, Ca, Mg

31. Different Methods to Measure EC 1:2 SME Indication PourThru 0 to 0.3 0.3 to 0.8 0.8 to 1.3 1.3 to 1.8 1.8 to 2.3 > 2.3 0 to 0.8 0.8 to 2.0 2.0 to 3.5 3.5 to 5.0 5.0 to 6.0 > 6.0 0 to 1.0 1.0 to 2.6 2.6 to 4.6 4.6 to 6.5 6.6 to 7.8 > 7.8 Very Low Low Normal High Very High Extreme

32. Marigold problem

33. Marigold problem

34. Tissue analysis Marigold problem

35. Sending tissue samples for analysis • For routine analysis: young, but full-grown leaves near the top of the canopy • Rinse the leaves gently if fertilizer was applied with an overhead irrigation system • B, Ca, Fe, Mn, Zn (not readily translocated within the plant) • Younger leaves

36. Chrysanthemums • Upper leaves – N, Ca, S, Fe, B • Lower leaves – K, Mg, Zn • Upper or lower leaves – P, Mn • Middle leaves – Cu • Routine analysis – most recent fully mature leaf

37. Tissue Analysis • Concentrations of macro- and micronutrients • These analyses may or may not include recommendations, depending on the lab

38. Testing The Waters…

39. Water Quality Kit

40. Analytical Lab

44. Need test for alkalinity • Need Fluorine (F) and/or Chlorine (Cl) if high levels are suspected.

45. Summary of Basic Tests • Fertilizer solution • Greenhouse medium • Plant tissue • Water