Micronutrient Compatibility with Pesticides and NPK Fertilizers. Brian Haschemeyer Director of Discovery and Innovation

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1 Micronutrient Compatibility with Pesticides and NPK Fertilizers Brian Haschemeyer Director of Discovery and Innovation

2 When you have a tank mix question or issue what do you do? Google it Jar Test If its on the internet it must be fact Call Trusted Advisor 2

3 I like to know Why and How Who else likes to know why and how? 3

4 Name the Structure - Chelates What do they have in common? EDTA chelating metal HO OH OH OH OH OH OH O + Na + O Glucoheptonate complexing agent EDDHA chelating agent Citric Acid chelating agent

5 It Helps if Understand Ammonia Chemistry Basics Yes I as your presenter already know that most of you don t like chemistry and you didn t come here to sit through a chemistry class. NH 4 + NH 3 - ph 9 Equilibrium point 5

% of ligand Ammonia (NH 3 NH 4+ ) ph and concentration dependent Ammonium (NH4+) is deprotinated to ammonia (NH3) in alkaline conditions so solutions need to be sufficiently alkaline (ph s >9) to

6 % of ligand Ammonia (NH 3 NH 4+ ) ph and concentration dependent Ammonium (NH4+) is deprotinated to ammonia (NH3) in alkaline conditions so solutions need to be sufficiently alkaline (ph s >9) to allow ammonia to complex metal. Common for use in polyphosphate solutions. Ammonium is often used to complex metals in conjunction with other organic acids such as citric acid. Ammonia 100 Stepwise Formation Constants 90 ion K n log K n 80 [Cu(NH 3 )(H 2 O) 5 ] 2+ K [Cu(NH 3 ) 2 (H 2 O) 4 ] 2+ K [Cu(NH 3 ) 3 (H 2 O) 3 ] 2+ K [Cu(NH 3 ) 4 (H 2 O) 2 ] 2+ K NH 4 + NH 3 [Cu(NH 3 ) 4 (H 2 O) 2 ] 2+ K f Equilibrium Reaction Log K f 10 Cu NH 3 [Cu(NH 3 ) 4 ] ph Zn NH 3 [Zn(NH 3 ) 4 ]

7 Take Away: Ammonia with Metals Take away concepts: 1. At alkaline phs above 9 ammonia has a partial negative charge and is volatile. 2. The negatively charged ammonia can coordinate with metals such as Zinc, Copper, etc. 3. It takes a high concentration of ammonia to metal to provide any significant amount protection to the metal 7

8 % of Zn++ Citrates Ammoniated Citrates are Common for use with Citric acid is natural biodegradable chelate. Because of its carboxyl groups, citric acid chelates / complexes metals in the acidic environment. Often used for formulation stability and foliar applications Citrate pka Log Kf pk pk pk Zinc Citrate 15mmol Zn : 20mmol Citrate 100 Stability Constants (Log K Values) Free Zn++ [M][H][L] [M][L] Zn(OH) 2 (s) CITRATE [MHL]/[M][H][L] [ML]/[M][L] Al Ca Cu Fe Fe Mg Mn ph Zn R.M Smith; A.E. Martell, Crtical Stability Constants, Plenum Press, New York and London, 3rd Edition.

EDTA pk 1 pk 2 pk 3 pk 4 pk 5 pk 6 0.0 1.5 2.0 2.66 6.16 10.24 Log Kf = 24.06 Log Kf = 22.56 Log Kf = 21.06 Log Kf = 19.06 Log Kf = 16.4 Log Kf = 10.

9 EDTA pk 1 pk 2 pk 3 pk 4 pk 5 pk Log Kf = Log Kf = Log Kf = Log Kf = Log Kf = 16.4 Log Kf = Ion [M][H][L] [M][L] Al Ca Cu Fe Fe Mg Mn Zn O OH O O NH + NH + OH OH O OH

10 Water 10

11 Water 11

12 Take Away: Ammonia with Metals Take away concepts: 1. At alkaline phs above 9 ammonia has a partial negative charge and is volatile. Below ph 9 they have a positive charge and are not coordinating with metal 2. The negatively charged ammonia can coordinate with metals such as Zinc, Copper, etc. 3. It takes a high concentration of ammonia to metal to provide any significant amount protection to the metal 4. Ammoniated metals fail when diluted in water 12

13 Take Away: Zinc Citrates 1. Sufficiently strong enough to be mixed with water 13

14 Take Away: Zinc EDTA 1. Strong enough to be mixed with water 14

17 Take Away: Ammonia with Metals 1. At alkaline phs above 9 ammonia has a partial negative charge and is volatile. Below ph 9 they have a positive charge and are not coordinating with metal 2. The negatively charged ammonia can coordinate with metals such as Zinc, Copper, etc. 3. It takes a high concentration of ammonia to metal to provide any significant amount protection to the metal 4. Ammoniated metals fail when diluted in water 5. Ammoniated Zinc should not be mixed and stored with for long periods of time Presentation title in footer (if desired) Month 00,

18 Take Away: Zinc Citrates 1. Sufficiently strong enough to be mixed with water 2. Sufficiently strong enough to be mixed with Presentation title in footer (if desired) Month 00,

19 Take Away: Zinc EDTA 1. Strong enough to be mixed with water 2. Strong enough to be mixed with Presentation title in footer (if desired) Month 00,

22 Take Away: Ammonia with Metals 1. At alkaline phs above 9 ammonia has a partial negative charge and is volatile. Below ph 9 they have a positive charge and are not coordinating with metal 2. The negatively charged ammonia can coordinate with metals such as Zinc, Copper, etc. 3. It takes a high concentration of ammonia to metal to provide any significant amount protection to the metal 4. Ammoniated metals fail when diluted in water 5. Ammoniated Zinc should not be mixed and stored with for long periods of time 6. Ammoniated Zinc fail in the ortho-phosphate solutions Presentation title in footer (if desired) Month 00,

23 Take Away: Zinc Citrates 1. Sufficiently strong enough to be mixed with water 2. Sufficiently strong enough to be mixed with Not strong enough to be mixed with ortho-phosphates. Reactions are not always immediate Presentation title in footer (if desired) Month 00,

24 Take Away: Zinc EDTA 1. Strong enough to be mixed with water 2. Strong enough to be mixed with Strong enough to be mixed with ortho-phosphates. 24

25 % of Ca++ % of Ca++ % of ligand Phosphate Interactions ph Dependence of Phosphate Binding Dissociation of Phosphoric acid H3PO4 100 Acid Mol. Form pka H 3 PO 4 H 2 PO H 1 PO PO H 3 PO 4 H 2 PO 4 - H 1 PO 4-2 PO 4-3 [M] +n Form Ksp Ca+2 Ca 3 (PO 4 ) 2 1x10-26 Ca 2 (PO 4 ) 2 (OH) 2 1x ph Ca 5 (PO 4 ) 3 (OH) 3 1x10-57 Phosphate Interactions with Calcium vs ph 100 Phosphate interactions wiht Calcium vs ph Ca Ca+2 70 Ca 5 (PO 4 ) 3 (OH) 3 70 Ca 3 (PO 4 ) ph ph 8 10 Graph based on 200mmol phosphate & 20mmol Ca+2 concentrations

26 EDTA Chelates Efficiency Factors EDTA chelating metal EDTA chelates can with stand the harsh conditions of the soil Efficiency Ratios reported in literature vary depending on soil conditions and can go above 6x in harsh conditions Zinc EDTA treatments had concentrations 5 times higher than other zinc treatments (Gangloff, 2004) Up to 5x Zinc EDTA efficiency ratios over other sources (Alloway, 2004) Zn EDTA increased zinc content of the crop twice as much as zinc sulfate in neutral solutions and up to 6 times as much in calcareous soil (Holden, Brown, 1965) Ideal for Liquid Starter Fertilizers Compatible with most all types of NPK solutions including orthophosphates and alkaline solutions

27 Brandt Sequestar Fe - EDDHA For alkaline conditions A high-performance chelating agent used in Agriculture particularly with iron in alkaline soil conditions.

28 Brandt Sequestar Fe EDDHA

29 Phenoxy Herbicides Do you recognize any functional groups? Carboxyl groups 2,4 D pka = 2.7 Fluazipop pka = 3.1 What about the ester formulation? O O R + R 1 R OH O R 1 32

30 Glyphosate Solution Chemistry Interactions between Cations and Glyphosate Stability Constants 1:1 molar physiological ph Cation (LogK m1 ) Ca Mg Cu Fe Fe Mn Zn

31 Carboxyl group key function group of many Ag chemicals Chelates, Complexes and Herbicides R pka - 1 O OH pka pka + 1 O O R + H + R O - O - pka - 1 is the ph value where the carboxyl groups exhibits no charge 100% of the time The pka value is ph value where the functional groups if protonated 50% of the time pka + 1 is the ph value where the carboxyl groups has a negative charge 100% of the time 34

32 Phenoxy herbicides Contain carboxyl groups Active Salt / Ester pka pka + 1 Formul ation Type Chemical Class acid structure Water Solubility Notes 2,4-D SL phenoxy acid R 1 -COOH Acid and ester forms are sparingly soluble, the salts have high solubility. Formulated as both a water salt and oil soluble ester 2,4-DB SL phenoxy acid R 1 -COOH Fenoxapr op-p EC phenoxy acid R 1 -COOH Fluazifop EC phenoxy acid R 1 -COOH Fluazifop- P-Butyl EC phenoxy acid R 1 -COOH Acid and ester forms are sparingly soluble, the salts have high solubility. Formulated as both a water salt and oil soluble ester Sparingly soluble - Products on market are Emulsifiable Concentrates Sparingly soluble - Products on market are Emulsifiable Concentrates Sparingly soluble - Products on market are Emulsifiable Concentrates 35

33 ph precipitation soluble liquid herbicide Reflex Herbicide Active: 2,4-DB SL Formulation pka = 4.8 Acid form is sparingly soluble, the salts have high solubility. Typically sold as a sodium salt Water ph 7.1 MAP ph

3.8 Acid form is sparingly soluble, the salts have high

34 ph precipitation soluble liquid herbicide Reflex Herbicide Active: Sodium Fomesafen SL Formulation pka = 3.8 Acid form is sparingly soluble, the salts have high solubility. Typically sold as a sodium salt Water 7.1 MAP ph

35 Suspension concentrate failure in presence of divalent cations Warrant Herbicide Active: Acetochlor SC Formulation Anionic dispersant fails do to binding divalent cations binding to the negative charged sites of the dispersant. Water Zn 38

Suspension Concentrate failure in 10-34-0 Force Insecticide Active:

formulations are typically SC or EC Dispersant fails do to limited

36 Suspension Concentrate failure in Force Insecticide Active: Tefluthrin SC Formulation Sparingly soluble in water, liquid formulations are typically SC or EC Dispersant fails do to limited water to activate dispersing and emulsifying agents. Water UAN 39

37 Humic Acid in Liquid Fertilizer UAN Calcium Nitrate 40

38 UAN and ATS with Pre-emerge Herbicide Lexar EZ, Bicep II Magnum, etc. SC Formulation Sparingly soluble in water, liquid formulations are typically SC or EC Dispersant fails do to limited water to activate dispersing and emulsifying agents. Hi electrolyte solution, limited free water. Water UAN ATS 41

fertilizers with Dicamba NH 4 + AMS Solutions ATS Solutions UAN

39 Counter Ion Affects Volatility of Dicamba Ammonium can increase volatility Be caution of adding ammonium containing liquid fertilizers with Dicamba NH 4 + AMS Solutions ATS Solutions UAN Solutions MAP Solutions Dicamba, Diglycolomine salt Dicamba, Dimethylamine salt 42

40 Glyphosate Antagonized by Divalent Cations -2 Mn +2 0 Glyphosate Glyphosate bound to Mn 43

41 Thank You

Fluid Compatibility Issues - Pesticides. Brian Haschemeyer December, 2013

Fluid Compatibility Issues - Pesticides Brian Haschemeyer December, 2013 Name the Structure What do they have in common? OH EDTA chelating metal EDDHA chelating agent OH O OH + Na+ O HO OH OH OH Glucoheptonate