Key Steps. Problem(Loca,on! Nutritional Disorders: Part 2 Mobile Elements. Mobile (older leaves) 3/20/13& Problem(Loca,on! -H 2 0. Immobile. !9Mo!

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1 Key Steps Nutritional Disorders: Part 2 Mobile Elements Brian Whipker Successful growing of greenhouse crops require managing the ph and fertility levels. If nutritional problems occur, knowing the location of leaf symptoms is the key for determining the cause. Focus on the Mobile Elements Problem(Loca,on! Problem(Loca,on!!"!Ca!!!9B! -H 2 0!YOUNG! BOTH OLD Immobile!Par,ally( Mobile! Mobile! -Fe -Mn!9S!!9N(((9P!!9Mg!!Young!!Old!!9Zn(((9Cu!!9Mo!!9K!!+Mn/+Fe! +EC(((+B! Mobile Elements (lower leaves) Nitrogen Phosphorus Magnesium Potassium Other Elements Low ph High EC Boron Toxicity Mobile (older leaves) Chlorosis is main early symptom Uniform chlorosis N P Interveinal chlorosis Mg Spotting purplish-black Low ph induced Mn/Fe toxicity Necrosis rapid High EC K Excessive B 1&

2 Mobile (older leaves) Chlorosis is main early symptom Uniform chlorosis N P Interveinal chlorosis Mg Spotting purplish-black Low ph induced Mn/Fe toxicity Necrosis - rapid High EC K Excessive B Nitrogen!(N)!/!Low!EC& Lower!leaves:!total!leaf!yellowing,!which! turns!necro=c!over!=me!! Recently!transplanted!plug!with!N!deficiency.& Lower!Leaf!Yellowing!and!Loss& Total&leaf& yellowing& Total&leaf& yellowing& Nitrogen!Deficiency! Nitrogen!Deficiency! 2&

3 Complete& leaf&necrosis& Complete& leaf&necrosis& Low!EC! Low!EC! Nitrogen (N) Uniform chlorosis, then necrosis on older leaves Stunting Early flowering Possible red coloration Leaf abscission Lower!Leaf!Yellowing!and!Loss& Gerbera Response to N Rates Gerbera Response to N Rates!!!!!!!50!!!!!!!!75!!!!!!!!!!100!!!!!!!!200!!!!!!!!!!300!!!!!!!400&!!!!!!50!!!!!!!!!75!!!!!!!!!!100!!!!!!!!200!!!!!!!!!!300!!!!!!!400& Too!Low& Optimal Too!High& Brian Whipker, Ka Yeon Jeong, and Ingram McCall, NC State University, Jonathan Frantz, USDA-ARS Toledo! 3&

4 SME & 1:2 3/20/13& N&is&supplied&in&the& greatest&quan.ty& It&is&the&primary& contributor&to&ec& Nitrogen&/&EC& High!EC! Hunger!Groups! Light Moderate Heavy Azalea Calceolaria Cineraria Begonia Pansy Primula Alstroemaria Bougainvillea Cleome Clerodendrum Dahlia Lilies Sunflower Calibrachoa Petunias (veg) Geraniums Mums Poinsettias Nitrogen!Deficiency! Low!EC! Target&Nutri.onal&Ranges& Drip or Sub Overhead SME & 1:2 PourThru Increasing&Fer.lizer&Conc.! 0 &increasing!ec! Petunia&Target&EC& by& Tes.ng&Methods& N - Corrective Procedures Too High Decrease N fertilization rate Increase clear water irrigations Leach with clear water twice within a few hours Too Low Increase N fertilization rate Limit clear water irrigations Reduce leaching Consider adding slow release fertilizer Parameter (SME) Gerberas NO - 3 (ppm) 100 to 200 NH + 4 (ppm) 5 to 10 4&

5 Phosphorus!(P)& "P! Lower!leaves:!purple!colora=on.! Overall!plant!color!darker!green! P!Deficiency:!Lower!leaves!with!purple!colora=on! "P! Low P Severe deficiency symptoms Purpling& Roots&are& normal& Phosphorous!Deficiency! Purpling& Roots&are&normal& Purpling& Roots&are&dark& & #1&purple& discolora.on& #2&stun.ng& #3&wil.ng& Root&rot&(Pythium&/&Phytophthora)& Phosphorous!Deficiency! Black!Root!Rot! 5&

6 P!Deficiency& "P! Phosphorus!(P)& Lower!and!upper!leaves!with!purple!colora=on! "P! Lower!leaves:!yellow!with!gray!spoVng! "P! "P! Nitrogen (N) Uniform chlorosis, then necrosis on older leaves Stunting Early flowering Possible red coloration Leaf abscission Phosphorus (P) Deep green foliage Severe stunting Chlorosis then necrosis of older leaves Possible purpling Roots longer and fewer Check for root problems P!Deficiency:!Leaf!spoVng! "P! P - Corrective Procedures Too High Decrease P fertilization rate (avoid or ) Increase clear water irrigations Leach with clear water twice within a few hours Too Low Increase P fertilization rate (use or ) Limit clear water irrigations Reduce leaching Consider adding slow release fertilizer ( ) Parameter (SME) Gerbera P (ppm) 5 to 20 Notes Check roots for rot or water soaked conditions Nitrogen (N) Uniform chlorosis, then necrosis on older leaves Stunting Early flowering Possible red coloration Leaf abscission Phosphorus (P) Deep green foliage Severe stunting Chlorosis then necrosis of older leaves Possible purpling Roots longer and fewer Check for root problems 6&

7 Mobile (older leaves) Chlorosis is main early symptom Uniform chlorosis N P Interveinal chlorosis Mg Spotting purplish-black Low ph induced Mn/Fe toxicity Necrosis - rapid High EC K Excessive B Loca=on!of!Interveinal!Chlorosis& Upper! "Fe! "Mg! Lower! Iron!(Fe)!or!Magnesium!(Mg)!Deficiency?& Iron!(Fe)!or!Magnesium!(Mg)!Deficiency?& Interveinal!yellowing!(chlorosis)! Interveinal!yellowing!(chlorosis)! Iron!(Fe)!or!Magnesium!(Mg)!Deficiency?& Loca=on!of!Interveinal!Chlorosis& RoseUe&leaf& arrangement& make&visual& diagnosis& difficult.& Over&.me& symptoms&can& cover&en.re& plant.& Interveinal!yellowing!(chlorosis)! Upper! "Fe! Confirma,on(Step:( Test(pH((~>6.4)( "Mg! Lower! Confirma,on(Step:( Soil(+(,ssue(sample( 7&

8 Magnesium!(Mg)& Magnesium!(Mg)& Ini=ally!lower!leaves!with!interveinal!yellowing! More!pronounced!interveinal!yellowing! Magnesium!(Mg)& Magnesium!(Mg)& Lower!leaves:!interveinal!yellowing! Over!=me,!necrosis!occurs! Interveinal& chlorosis& Interveinal& chlorosis& Magnesium!Deficiency! Magnesium!Deficiency! 8&

9 Interveinal&chlorosis,&then&necrosis& Magnesium!(Mg)& Lower!leaves:!interveinal! yellowing,!which! over!=me!turn!necro=c.! Advanced!Magnesium!Deficiency! Mg - Corrective Procedures Too High Decrease Mg fertilization rate (decrease MgSO 4 applications) Notes Test water for Mg levels Maintain K:Ca:Mg balance of 4:2:1. Too Low Increase Mg fertilization rate (use MgSO 4 at 1 to 2# / 100 gal water) Notes has insufficient Mg Test water for Mg levels Maintain K:Ca:Mg balance of 4:2:1. Magnesium (Mg) Older leaves with an interveinal chlorosis then necrosis Necrosis follows, typically beginning along the midrib Iron (Fe) Parameter (SME) Gerbera Mg (ppm) 50 to 75 Loca=on!of!Interveinal!Chlorosis& Hi!pH!(Iron!Deficiency)& "Fe! "Mg! Upper! Lower! Upper!leaves:!with!interveinal!chlorosis! 9&

10 Hi ph (Iron Deficiency) High!pH!(Iron!Deficiency)& Ini,al:( Slight(interveinal( chlorosis(of(recently( matured(leaf( Moderate:( Interveinal(chlorosis( more(pronounced,( spread(to(other( leaves( Advanced:( Bleached((white)( interveinal((chlorosis(( Ini,al:( Slight(interveinal( chlorosis(of(recently( matured(leaf( Moderate:( Interveinal(chlorosis( more(pronounced,( spread(to(other( leaves( Advanced:( Bleached((white)( interveinal((chlorosis(( Leaves& &Upper& Interveinal& chlorosis&leads& to&bleaching& and&necrosis& with&advanced& symptoms& Magnesium!(Mg)! Iron (Fe) Younger leaves with interveinal chlorosis Yellow color becomes white over time Necrosis follows Substrate ph typically >6.4 High&pH&induced&Fe&deficiency& High ph or??? Root rot and overwaterin g can also induce iron problems. Random pattern Check the roots. 5.2& Gerbera Target ph Zone 5.4& 5.6& 5.8& 6.0& 6.2& 6.4& 6.6& 6.8& 10&

11 Gerbera Substrate ph Range Optimal range is between 5.8 and & 4.5& 5.0& 5.5& 6.0& 6.5& 7.0& 7.5& 8.0& NITROGEN& POTASSIUM& PHOSPHORUS& CALCIUM& MAGNESIUM& IRON& MANGANESE& Correc.ve&Procedures& &High&pH& Lowering&the&pH&to&acceptable&levels&corrects&problems.& Op.ons& Acidic&fer.lizers& Acid&water&drench& Iron&applica.ons& BORON& ZINC& COPPER& High ph Correction Use an Acidic Fertilizer , etc Extremely acidic: Acid Water Drench Use sulfuric acid to acidify your irrigation water to ph 4.0 to 4.5. Apply as a substrate drench Rinse foliage ASAP High&pH&Correc.on& Acid&Water&Drench& Use&sulfuric&acid&to&acidify&your&irriga.on&water&to& ph&4.0&to&4.5.& Apply&as&a&substrate&drench& Rinse&foliage&ASAP& High ph Correction Iron Drench (options) Iron-EDDHA: mix 5 oz in 100 gal of water Iron-DTPA: mix 5 oz in 100 gal of water Iron sulfate: mix 4-8 oz in 100 gal of water Apply as a substrate drench with sufficient volume to leach the pot. Rinse foliage ASAP Use with caution on iron efficient plants (geraniums) ph Problem Prevention Monitoring( with(the( PourThru( method(helps( prevent(ph( problems.!!!!!((( 11&

12 Loca=on!of!Interveinal!Chlorosis& "Fe! "Mg! Magnesium (Mg) Iron (Fe) Upper! Lower! Older leaves with an interveinal chlorosis then necrosis Necrosis follows, typically beginning along the midrib Younger leaves with interveinal chlorosis Yellow color becomes white over time Necrosis follows Substrate ph typically >6.4 Confirma,on(Step:( Test(pH((~>6.4)( Confirma,on(Step:( Soil(+(,ssue(sample( Key Points Target the ph between 5.8 and 6.3 Target Mg at 50 to 75 ppm Maintain a K to Ca to Mg ratio of 4:2:1 to avoid antagonisms. Mobile (older leaves) Chlorosis is main early symptom Uniform chlorosis N P Interveinal chlorosis Mg Spotting purplish-black Low ph induced Mn/Fe toxicity Necrosis - rapid High EC K Excessive B Low!pH!(Iron/Manganese!Toxicity)& Manganese (Mn)/ Iron (Fe) Toxicity Older leaves with purplish-black spotting Overall chlorosis can occur Necrosis follows Substrate ph typically <5.5 Lower!leaves!with!purplish"black!spoVng! 12&

13 Low ph (Iron/Manganese Toxicity) Low ph (Iron/Manganese Toxicity) Low ph (Iron/Manganese Toxicity) Low ph (<5.5) problems occur as iron/ manganese toxicity. Lower leaves develop black spotting. Total&leaf& yellowing,& necrosis& Top&growth& discolored& Substrate!mix!without!lime,!pH!3.0! Pa`ern!clearly!seen!between!mixes! Total&leaf& yellowing,& necrosis& Top&growth& discolored& Lower&leaf&yellowing,&followed&by& necro.c&spoang& Low!pH! Substrate!mix!without!lime,!pH!3.0! Appears!the!low!pH!situa0on!is!manifes0ng!itself!as!low!pH!induced!lower!leaf!loss!and! maybe!calcium!deficiency!of!the!new!growth.! 13&

14 Growth&stunted&with&low&pH& Low!pH! Low&pH& #!Lime/Yard 3 :!!!!!!!!0!!!!!!!!!!!!!!!!!!!5!!!!!!!!!!!!!!!!!!!!!!!10! Resul=ng!pH:!!!!!!!3.3!!!!!!!!!!!!!!!!4.8!!!!!!!!!!!!!!!!!!!!!!5.1! Dry(weight( Reduc,on:(!!!!!59%((((((((((((((29%((((((((((((((((((((((99( Manganese (Mn)/ Iron (Fe) Toxicity Older leaves with purplish-black spotting Overall chlorosis can occur Necrosis follows Substrate ph typically <5.5 Gerbera Target ph Zone ph&c&op.mal&ranges&by&group& Parameter Low (Petunia) General (General) High (Geranium) ph 5.3 to to to & 5.4& 5.6& 5.8& 6.0& 6.2& 6.4& 6.6& 6.8& Goals:( Avoiding!HIGH!pH! problems! Avoiding!LOW!pH! problems! Correc.ve&Procedures& &Low&pH& Increasing&the&pH&to&acceptable&levels&corrects&problems.& Op.ons& Flowable&lime& Hydrated&lime& Potassium&bicarbonate& Low&pH&Correc.on& Flowable&Lime& Use&1&to&2&quarts& per&100&gallons&of& water.& Rinse&foliage.& 14&

15 Low&pH&Correc.on& Hydrated&Lime& Mix&1#&in&3&to&5&gal&of&WARM&water.&& Mix&twice.&Let&seUle.&Decant&liquid& and&apply&thru&injector&at&1:15.& Caus.c&(rinse&foliage&ASAP&and&avoid& skin&contact)& Low&pH&Correc.on& Potassium&Bicarbonate&(KHCO 3 )& Use&2&#&per&100&gal&of&water& Rinse&foliage&ASAP& Provides!933!ppm!K& Leach&heavily&the&following&day&with&a& complete&fer.lizer&to&reduce&ec&levels& and&restore&nutrient&balance.& Low&pH&Correc.on& Warning!!!!& Flowable&Lime& Avoid&damage&to&your&injector&by&using&rates&of& 2&qts&per&100&gal&of&water,&or&less& Can&split&applica.ons& Potassium&Bicarbonate&(KHCO 3 )& Rates&greater&than&2&#&per&100&gal&of&water&can& cause&phytotoxicity!& Key Points Target the ph for optimal growth Varies by species This helps to avoid both low and high ph problems. Mobile (older leaves) Chlorosis is main early symptom Uniform chlorosis N P Interveinal chlorosis Mg Spotting purplish-black Low ph induced Mn/Fe toxicity Necrosis - rapid High EC K Excessive B High EC Marginal leaf necrosis Stunting Check substrate EC Potassium (K) Stunted growth Marginal leaf necrosis Boron!Toxicity! (B)! Marginal&leaf& necrosis& Appears&aier&a& B&applica.on& 15&

16 High EC Marginal leaf necrosis Stunting Check substrate EC Potassium (K) Stunted growth Marginal leaf necrosis Boron!Toxicity! (B)! Marginal&leaf& necrosis& Appears&aier&a& B&applica.on& Electrical!Conduc=vity!(EC)!"!High! Lower!leaves:!crinkled! Marginal!leaf!burn! Less!growth!likely! Sub"irrigated!plants:!Less!upper!root!growth! High EC High EC Marginal leaf burn from high EC and water stress. Advanced lower leaf burn due to high EC. High!EC& High!EC& Moderate! marginal!bract! burn!from!a! slow!release! fer=lizer! dump! Severe! marginal!bract! burn!from!a! slow!release! fer=lizer! dump! 16&

17 Leaf&margin& necrosis& Leaf&necrosis& PHOTO& High&EC& Fer.lizer&Burn& Leaf&necrosis& EC Testing Procedures In-House Testing A substrate EC test (1:2 or PourThru) Lab Testing SME test to determine actual EC levels in the substrate. Fer.lizer&Burn& EC - Corrective Procedures Too High Decrease fertilization rate Increase clear water irrigations Leach with clear water twice within a few hours Too Low Increase fertilization rate Limit clear water irrigations Reduce leaching Consider adding slow release fertilizers Potassium!(K)& Moderate! Advanced! Parameter (SME) Gerbera EC (ms/cm) 1.0 to 2.0 Lower!leaves:!interveinal!white!or!yellow!! spovng,!which!over!=me!turn!necro=c! 17&

18 K - Corrective Procedures Too High Decrease use of K based fertilizer (KNO 3 ) until balance restored. Notes Maintain K:Ca:Mg balance of 4:2:1. Maintain N:K balance between 1:1 or 2:1.5. Too Low Apply KNO 3 at 200 to 300 ppm K Notes Plants with extensive stalks have higher K requirements Check to determine if tissue Na levels are excessive K : Ca : Mg Ratio Use a K : Ca : Mg ratio of 4:2:1 to limit any antagonisms. Example (ppm): 200 K:100 Ca:50 Mg Tissue& %& 3.5& 3.0& 2.5& 2.0& 1.5& 1.0& 0.5& Ca& Mg& K& Parameter Poinsettias K (ppm) 150 to 300 K&Fer.liza.on&Rate& Boron!Toxicity!(B)& Key Points Customize the ph for the crop. Optimal plant growth achieved with between 100 to 300 ppm N being applied, from a complete fertilizer. Lower!leaves:!marginal!necrosis! 25!Bedding! Plant! Chapters& Available from Amazon.com& Partnering Universities 18&