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Biostimulants and Ballfields

Biostimulants and Ballfields. Erik Ervin, Professor Turfgrass Culture & Physiology Virginia Tech. Two main biostimulant ingredients. Humics = humic and fulvic acids A natural source of rooting hormone = AUXIN Seaweed extracts A natural source of chlorophyll-stabilizing hormone = CYTOKININS.

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Biostimulants and Ballfields

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  1. Biostimulants and Ballfields Erik Ervin, Professor Turfgrass Culture & Physiology Virginia Tech

  2. Two main biostimulant ingredients • Humics = humic and fulvic acids • A natural source of rooting hormone = AUXIN • Seaweed extracts • A natural source of chlorophyll-stabilizing hormone = CYTOKININS

  3. Humic Substances Derive from the decomposition (or humification) of carbon containing compounds (plant or animal) Source: Brady & Weil, Soil Science

  4. Humic Substances defined • Humic substances comprise 60-80% of soil OM and are the components of OM most resistant to microbial decomposition • Classified into: • Fulvic acid: smallest & soluble in acid & alkali • Humic acid: medium & soluble in alkali • Humin: largest, most persistent, dark, insoluble • Sources • Leonardite (mined soft coal, lignite): 30-80% HA, 150 CEC • Peats: 5-25% HA, • Biosolids/Compost: 3-15% HA

  5. Humic Acid has been shown to increase photosynthesis and root growth • In a greenhouse experiment, Crenshaw bent was grown in solution culture supplied with non-limiting nutrients (no stress) and 3 concentrations of HA. • Photosynthesis and root growth was increased significantly from 1 to 4 weeks after treatment by HA at 400 ppm (0.0004%) • VT foliar spray rate ~5000 ppm Liu, Cooper, Bowman. 1998. HortScience 33:1023-1025

  6. Auxin or IAA: a component of humics • Produced in new leaves • Cell division & Stem elongation • Induction of rooting • In combination with cytokinins they regulate ratio of tillering to root initiation and growth • Bending of shoots toward light, roots towards gravity • IAA overproducing mutants of Arabidopsis are known as “rooty” and “superroot” Rogg & Bartel. 2001. Developmental Cell. 1(5):595

  7. KBG sod establishment on sand • Two humic substances sources compared against fertilizer only; fertilizer inputs equalized • Peat based versus leonardite, both applied at 3 oz/M every 2 wks for 6 applications 34 and 73% transplant rooting increase

  8. KBG sod establishment on sand Ervin et al., 2005. Acta Hort

  9. Kelp or Seaweed Extracts (SWE) • Why do they tend to be in every biostimulant? • Where do they come from and what’s in them? • N. Atlantic rockweed=brown algae=Ascophyllum nodosum • Contain carbos, aminos, minor nutrients, CYTOKININS, Auxin, GA betaines (dehydration avoiders)

  10. Stay-green mutant of corn due to maintenance of high leaf cytokinin levels Loss of ACC oxidase expression stops ethylene’s effects on cytokinin degradation and senescence is delayed under drought (above) and light deprivation (below) From: D. R. Gallie, Biochemistry, UC-Riverside

  11. Root-injection of synthetic cytokinin improved bentgrass heat stress tolerance Means are from 56 d of heat treatments and 56 d after Zeatin Riboside (ZR) injection into the root zone; All mean comparisons are diff. at P=0.05 Adapted from Liu et al., 2002. Cytokinin effects on creeping bentgrass responses to heat stress. Crop Sci. 42:457-472.

  12. Root-injection of synthetic cytokinin improved bentgrass heat stress tolerance Means are from 56 d of heat treatments and 56 d after Zeatin Riboside (ZR) injection into the root zone; All means are sig diff. at P=0.05 Adapted from Liu et al., 2002. Cytokinin effects on creeping bentgrass responses to heat stress. Crop Sci. 42:457-472.

  13. Seaweed extract (SWE) contains cytokinins (75-100 ppm) and improved bentgrass drought resistance Data taken at end of 28-d dry-down where Θv = 5%; All mean comparisons are diff. at P=0.05 Adapted from Zhang and Ervin, 2004. Crop Science, 44:1737-1745

  14. SWE + HA improve creeping bentgrass drought resistance 5.4 b 5.5 b 6.3 a 4.4 c Av. Quality for Penncross, L-93, G-2 1.12 b 1.45 a 1.60 a 0.95 c Av. root mass for Penncross, L-93, G-2 Source:Zhang and Ervin, 2004. Crop Science, 44:1737-45

  15. HA+SWE had no effect under optimum temperature and moisture conditions Ervin &Zhang Turf kept at FC = 34% H20

  16. Check Aca SWE OO SWE CK-check ashed-SWE End of 2006 trial, 49 days of heat stress

  17. Biostimulant Testing on Virginia Tech’s Soccer Game Field Erik Ervin Josh McPherson and X. Zhang Virginia Polytechnic Institute and State University

  18. Field Details • Rootzone is a modified soil, Cambridge sand-slit system installed in summer 03. • Big-roll Kentucky bluegrass sod installed July 28, 2003 over a 1” sand cap and played on 3 weeks later • Getting adequate rooting through 1” layer was a problem

  19. Soccer Field Experiment Objective: determine the effects of various season-long biostimulant programs on field performance under regular season play (women’s soccer and lacrosse; men’s soccer) Measured: • Color and Percent Cover • Divot (or Shear) strength • Root strength • Antioxidant activity and Photochemical Efficiency

  20. Products Tested Soluble potash . . . . . . . . . . . . . . . 6% 1% Iron . . . . . . . . . . . . . . . . . . . . . . . . 1.4% 0.36% Humic and Fulvic acid extract . . . 35.4% 9% Kelp Extract . . . . . . . . . . . . . . . . . 4.8% 1.2% Siloxane surfactant . . . . . . . . . . . . 1.4% 0.36% Manure extract . . . . . . . . . . . . . . . . 0% 74.3%

  21. Products TestedIronRoots2 Guaranteed nutrient analysisAvailable Phosphate (P2O5) .................2.0%Soluble Potash (K2O) .........................4.0%Iron(Fe) ..........................................4.0%4.0% Chelated Iron (Fe)Derived from: Potassium Orlhophosphale andIron Citrate ComplexNon-plant food ingredientsHumic Substances.............................2.6%Cold Water Kelp Extracts....................2.0%Vitamin C (Ascorbic Acid)....................2.7%Vitamin B-| (Thiamine)........................0.3%Vitamin E (Alpha-tocopherol)...............0.1%Myo-lnositol.....................................0.4%Glycine............................................0.9% IronRoots2

  22. Products Tested Lebanon/Emerald Isle Phosphoric acid . . . . . . . . . . . . . . . 2% Soluble Potash. . . . . . . . . . . . . . . . 2% Kelp Extract . . . . . . . . . . . . . . . . . .100% + Convert (a humic acid product)

  23. Experiment Details Treatments: applied monthly at labeled rates from May to November • Focus • Launch • Focus + Launch • Roots program • PanaSea Plus + Convert • Untreated Control 4 replications in blocks around center circle; mowed at 2” (May-July) and 1.5” (Aug-Nov); 4.75 lb N/M with complete fertilizer applied May to November; diseases controlled preventively

  24. Events August: 12 September: 29 October: 24 November: 8 Total: 73

  25. Results: Turf Color (9 = darkest) (no differences)

  26. Results: Percent Turf Cover (no differences)

  27. 5/27/2004 Convert + PanaSea Plus Control Launch + Focus Roots Focus Launch

  28. 6/11/2004 Focus Launch Roots Launch + Focus Control Convert + PanaSea Plus

  29. 9/21/2004 Focus Launch Roots Launch + Focus Control Convert + PanaSea Plus

  30. Results: Physiological Health

  31. Results: Root and Shear Strength

  32. Summary • Under adequate fertilization, irrigation, and mild environmental conditions biostimulant programs had minor effects on Kentucky bluegrass field performance When to consider using: • Cool-season: During sod or seed establishment, especially in summer; in hot, dry years and on high profile fields with inadequate irrigation. Most likely not going to increase wear tolerance or recovery. • Bermudagrass: justification of use is most likely questionable; no effect on overwintering seen; perhaps kick-start spring re-rooting?

  33. Can monthly granular humate (2 lb/M) reduce summer N needs on bermuda? • Soil CEC increased from 4.3 (control) to 5.8 • Leaf N increased from 3.0% (control) to 3.5% (Sept) • No other nutrient increases; no strong visual color differences over the season; no roots measured Silt loam soil with 2.5% OM at VT

  34. 4. Amino Acids

  35. 20 essential amino acidsNitrogen is stored and transported in amino formsProteins are chains of 100’s of amino acids, usually containing all 20 in their chains

  36. What about foliar amino acid effects? • Why might a benefit be expected? • They most likely can be absorbed by leaves = smaller than sucrose • They may conserve carbohydrate during summer stress as carbohydrates are broken down in respiration to produce chemical energy (ATP and NADPH) to make amino acids…then proteins • Good candidates for formulations? Glutamine: initial product in AA production cycle; its level controls need for more or less N-assimilation Tryptophan:auxin precursor = root initiation Proline: primary osmoregulator for drought protection

  37. What are the barriers to nutrient absorption through the leaves ? • Primary ports of nutrient entry are: • Stomates(20,000/cm2 leaf) • Tiny pores in cuticular wax (10 billion/cm2 leaf) • Nutrient absorption occurs by: • Diffusion • Active transport

  38. Absorption is at its peak when stomates are fully open Stomate openings are about 10 µm wide Cuticle pores are 1 nm or less = 1000 times smaller than stomate openings, but there are 106 more Urea (COH4N2) is 0.44 nm in size; small enough to move through culticle pores Factors such as salinity, heat, and water stress will cause stomates to close

  39. Sizes of molecules to go through pores • Sucrose = 1 nm, mol. wt. = 342 • Glucose = 0.6 nm • Various inorganic ions 0.5 to 1 nm in their hydrated forms • Amino acids have mol. wt. of 75 to 204; they should pass through cuticular pores

  40. Bentgrass foliar uptake of N sources Stiegler & Richardson, UArk, 2008

  41. L93 bentgrass with complete nutrient solution: 0.25 lb N/M/month 75 F on mist bench, 3 month trial Tryptophan (3 mM/month) Glutamine (3 mM/month) Control Glutamine: initial product in AA production cycle; its level controls need for more or less N-assimilation = less root energy needed for nitrate uptake Tryptophan:auxin precursor = root initiation Amino acid dosing trial

  42. Results: Leaf Color

  43. Photochemical Efficiency

  44. Leaf Protein content (mg/g FW)

  45. Questions and Discussion

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