Greenhouse Diagnostics Workshop: Symptoms of Cultural and Environmental Challenges

Transcription

1 Greenhouse Diagnostics Workshop: Symptoms of Cultural and Environmental Challenges Thursday morning 9:00 am Where: Gallery Overlook (upper level) Room H There are many factors that can damage greenhouse crops in addition to pathogens and pests, many of which can mimic disease and insect injury: nutritional problems, irrigation issues, chemical burn, and a host of environmental concerns to name a few. Drs. Lopez and Whipker will review symptoms associated with many of these issues and the strategies for identifying and avoiding them in the future. Diagnostics guides and supplies will be provided to each participant and refreshments will be served. Registration limited; $65 fee. MI Recertification credits: 3 (COMM CORE, PRIV CORE) Moderator: Roberto Lopez, Horticulture Dept., MSU 9:00 am Greenhouse Diagnostics Workshop Roberto Lopez, Horticulture Dept., MSU Brian Whipker, Horticultural Science Dept., North Carolina State Univ. 2:00 noon Session Ends

2 Diagnostics: Symptoms of Cultural and Environmental Challenges Outline Introduction Key Diagnostic Questions Problem Diagnostics Distorted Growth Flower Problems Interveinal Chlorosis Wrap up and Questions Roberto Lopez Floriculture Research and Extension Brian Whipker Floriculture Extension and Research Diagnostics: Abiotic Disorders Diagnostics: Abiotic Disorders. Know Your Disorders 2. Key Information 3. Problem Solving. Know Your Disorders 2. Key Information 3. Problem Solving Steps Know your disorders A) Boron Deficiency B) PGR Overdose C) Broad Mites D) 2,4 D Herbicide E) Chemical Phyto A) Boron Deficiency B) PGR Overdose C) Broad Mites D) 2,4 D Herbicide E) Chemical Phyto Copyright Not for Publication

3 A) Boron Deficiency B) PGR Overdose C) Broad Mites D) 2,4 D Herbicide E) Chemical Phyto Grower Submitted Image Can you diagnose problems from only a photo? Diagnostics: Abiotic Disorders Diagnosing of Plant Problems Many problems mimic one another. Probability of incorrect diagnosis increases when one shoots from the hip. Additional information required to improve accuracy.. Know Your Disorders 2. Key Information 3. Problem Solving Steps for diagnosing problems Step : Action: Diagnostics: Abiotic Disorders Describe the crop and potential problem Determine if it is it truly a problem or supposed to look like that (a new cultivar)? Step 2: Action: Diagnostics: Abiotic Disorders Consider the possible agents Look for patterns in the crop and on the plant itself. Are the patterns random, scattered, or localized (likely biotic) or cover a large area (all plants) and uniform (likely abiotic)? Copyright Not for Publication 2

4 Diagnostics: Abiotic Disorders Diagnostics: Abiotic Disorders Step 3: Action: Gather as much information as possible Scout and examine leaves and roots closely for symptoms (reactions or alterations of a plant s normal appearance due to a disease or disorder) or signs (actual pathogen/insect, parts or by products seen on plant) Step 3: Gather information Action: Review crop records Cultural practices Proper planting Fertilizer, PGR, herbicide, and pesticide applications ph and EC Irrigation frequency Environmental conditions Temperature or light extremes Check host specificity many hosts may mean an abiotic disorder Diagnostics: Abiotic Disorders Diagnostics: Abiotic Disorders Symptoms: Alteration of normal appearance Necrosis or death Chlorosis Distorted growth Delay or lack of flowering Flower bud abortion Wilting Step 4: Action: Go into Sherlock Holmes mode Ask questions When was the problem first noticed Was the damage sudden or gradual? How old are affected plants? Percentage of plants affected? What is the degree of injury? Diagnostics: Abiotic Disorders Diagnostics: Abiotic Disorders Step 5: Diagnose Step 6: Corrective measures Action: Consult help (extension, bulletins, e GRO alerts, books, etc.). Consider all the possibilities from sources and others experiences. Eliminate options that aren t likely. Prove or disprove your diagnosis via testing (tissue analysis, water analysis, or substrate nutrient analysis, etc.) Action: Kristen Getter, MSU Correct the problem based on previous experience, extension or diagnostic lab recommendations, book recommendations, etc. Record what you did to fix it, so that you can make sure it worked and for your own future reference if the problem should occur again. Copyright Not for Publication 3

5 Diagnostics: Abiotic Disorders. Know Your Disorders 2. Key Information 3. Problem Solving Distorted Growth Flower Disorders Interveinal Chlorosis Crop & Symptoms Interveinal chlorosis of geranium The lower leaves exhibit interveinal chlorosis. Normal Growth Interveinal Chlorosis Distribution Most geranium plants (70%) of this cultivar exhibiting symptoms. Symptoms also noticeable on other cultivars. No symptoms on other plant species. Information: Plugs purchased. Limited pesticides applied after transplanting ph at 6.3 / EC (SME) at.88 ms/cm Fertilization: 200 N from Cal Mag Water Analysis: Geraniums Source: Well Element () N0 3 N NH 4 N P K Ca Mg Lab Results Interpretation Index Ok Ok Ok Ok Low Low Substrate Analysis: Geraniums Element () N0 3 N NH 4 N P K Ca Mg Lab Results Interpretation Index 69 S 5 S 62 S 68 S 4 L 39 L Element () Fe Mn Zn Cu B Lab Results Interpretation Ok Ok Ok Ok Ok Element () Fe Mn Zn Cu B Lab Results Interpretation Index Ok Ok Ok Ok Ok Parameter ph EC (SME: ms/cm) Bicarbonate (HCO 3 ) Lab Results Interpretation Low Extremely Low Extremely Low Parameter ph EC (SME: ms/cm) Lab Results Interpretation Upper End Mid to Upper End Copyright Not for Publication 4

6 Tissue Analysis: Geraniums Element N % P % K % Ca% Mg % S % Lab Results Interpretation Index 59 S 57 S 6 S 4 L 3 L 50 S Element Fe Mn Zn Cu B Lab Results Interpretation Index 6 S 58 S 57 S 52 S 5 S A) Mg Deficiency B) Iron (Fe) Deficiency C) Antagonism Induced Mg Def. D) Elevated substrate ph E) Root Rot b Corrective Procedures: Mg Deficiency Correction: Apply Epsom salts (Magnesium sulfate) at the rate of 2 # / 00 gallons of water. Preventative: Apply Epsom salts (Magnesium sulfate) at the rate of # / 00 gallons of water on a monthly basis. Crop & Symptoms Interveinal chlorosis of geranium The lower leaves exhibit interveinal chlorosis. Normal Growth (and video) Interveinal Chlorosis b b Distribution Most geranium plants (70%) of this cultivar exhibiting symptoms. Symptoms also noticeable on other cultivars. No symptoms on other plant species. Information: Plugs purchased. Limited pesticides applied after transplanting ph at 6.3 / EC (SME) at.88 ms/cm Fertilization: 200 N from Cal Mag Flowable lime applied twice at the rate of 2 quarts/00 gallons of water (3 &6 wks after transplant) Water Analysis: Geraniums Source: Well Element () N0 3 N NH 4 N P K Ca Mg Lab Results Interpretation Index Ok Ok Ok Ok Low Low Element () Fe Mn Zn Cu B Lab Results Interpretation Ok Ok Ok Ok Ok Parameter ph EC (SME: ms/cm) Bicarbonate (HCO 3 ) Lab Results Interpretation Low Extremely Low Extremely Low Copyright Not for Publication 5

7 b b Substrate Analysis: Geraniums Tissue Analysis: Geraniums Element () N0 3 N NH 4 N P K Ca Mg Lab Results Interpretation Index 69 S 5 S 62 S 68 S 80 E 39 L Element N % P % K % Ca% Mg % S % Lab Results Interpretation Index 59 S 57 S 6 S 0 E 3 L 50 S Element () Fe Mn Zn Cu B Lab Results Interpretation Index Ok Ok Ok Ok Ok Element Fe Mn Zn Cu B Lab Results Interpretation Index 6 S 58 S 57 S 52 S 5 S Parameter ph EC (SME: ms/cm) Lab Results Interpretation Upper End Mid to Upper End b b A) Mg Deficiency B) Iron (Fe) Deficiency C) Antagonism Induced Mg Def. D) Elevated substrate ph E) Root Rot Corrective Procedures: Mg Deficiency When applying Flowable Lime for ph management, follow with an Epsom salts (Magnesium sulfate) at the rate of # / 00 gallons of water. This helps restore the nutrient balance. Correction: Apply Epsom salts (Magnesium sulfate) at the rate of 2 # / 00 gallons of water. Preventative: Apply Epsom salts (Magnesium sulfate) at the rate of # / 00 gallons of water on a monthly basis. 2 2 Crop & Symptoms Interveinal chlorosis of poinsettia The upper leaves exhibit interveinal chlorosis. Lower Leaves: Normal Green Upper Leaves: Interveinal Chlorosis Distribution All plants (00%) have top leaves with interveinal chlorosis. Information: Plugs purchased from a specialty propagator. Standard fungicide drenches and spot treatment for whitefly control. ph at 6.7 / EC (PourThru) at 3.4 ms/cm Fertilization: 200 N from Dark Weather Feed Copyright Not for Publication 6

8 2 2 Substrate Analysis: Poinsettias Element () N0 3 N NH 4 N P K Ca Mg Lab Results Interpretation Index 73 H 4 S 50 S 74 S 54 S 37 L Element () Fe Mn Zn Cu B Lab Results Interpretation Index Ok Ok Ok Ok Ok A) Mg Deficiency B) Iron (Fe) Deficiency C) Elevated P D) Elevated substrate ph E) Root Rot/Over irrigation Parameter ph EC (SME: ms/cm) Lab Results Interpretation Upper End Mid Level 2 2b Corrective Procedures: High Substrate ph Iron Drench (options) Iron-EDDHA: mix 5 oz in 00 gal of water Iron-DTPA: mix 5 oz in 00 gal of water Iron sulfate: mix 4-8 oz in 00 gal of water Notes: Apply as a substrate drench with 0% leaching. Rinse foliage ASAP Avoid use on iron efficient plants (geraniums) Acid Water Drench Acidify the water to ~ph 4 Notes: Apply as a substrate drench with sufficient volume to leach the pot. Rinse foliage ASAP 4 02 Crop & Symptoms Interveinal chlorosis of clerodendrum The upper leaves exhibit interveinal chlorosis. Upper Leaves: Interveinal Chlorosis 2b 2b Distribution Scattered plants affected (2%), with upper leaf interveinal chlorosis. Most plants have normal growth Information: Plugs purchased from a specialty propagator. Limited pesticides applied after transplanting ph at 6.0 / EC (SME) at.3 ms/cm Fertilization: 00 N Roots white, but limited. Substrate very wet A) Mg Deficiency B) Iron (Fe) Deficiency C) Elevated P D) Elevated substrate ph E) Root Rot/Over irrigation Copyright Not for Publication 7

9 2b 2c Corrective Procedures: Emitter Flow Determine if irrigation flow can be made more even to avoid waterlogged conditions. Crop & Symptoms Interveinal chlorosis of scaevola The upper leaves exhibit interveinal chlorosis. Upper Leaves: Interveinal Chlorosis 2c 2c Distribution All scaevola plants (00%) with interveinal chlorosis Information: Plugs purchased from a specialty propagator. No pesticides applied after transplanting ph at 6.0 / EC (SME) at.53 ms/cm Fertilization: 200 N from A) Mg Deficiency B) Iron (Fe) Deficiency C) Elevated P D) Elevated substrate ph E) Root Rot/Over irrigation Corrective Procedures: P Overdose when applied at 200 N provides 42 P. Scaevola, similar to other Australian natives, are sensitive to high levels of P. Elevated levels of P tie up iron and lead to iron deficiency symptoms. Switch to a low P containing fertilizer 2c Keeping ph and EC on Right Track: ID, Monitoring, and Management Brian Whipker Floriculture Extension and Research Copyright Not for Publication 8

10 Keeping ph and EC on the Right Track. Rooting Environment ph 2. & EC Tips for Success What are the optimal substrate ph & EC ranges? Optimal Ranges Symptom ID Monitoring App Principle: Substrate ph Range Substrate ph has a significant affect on nutrient availability NITROGEN POTASSIUM PHOSPHORUS CALCIUM MAGNESIUM Parameter ph Optimal Ranges by Group Low (Petunia) General (General) High (Geranium) ph 5.5 to to to 6.5 Wide Range: 5.5 to 6.5 IRON MANGANESE Although there are species specific ranges BORON ZINC COPPER MOLYBDENUM Goals: Avoiding HIGH ph problems Avoiding LOW ph problems Suggested Greenhouse PourThru ph & EC Categories Substrate EC Categories Categories A. Low (.3 to 2.0 ms/cm) SME: 0.9 to.3 ms/cm :2: 0.4 to 0.6 ms/cm B. Medium (2.0 to 3.0 ms/cm) SME:.3 to 2.0 ms/cm :2: 0.6 to 0.9 ms/cm C. High (3.0 to 4.9 ms/cm) SME: 2.0 to 3.3 ms/cm :2: 0.9 to.5 ms/cm I Substrate ph Categories II III Venus Fly Trap Pansy Marigold New Guinea impatiens Hydrangea, Blue Few species Hydrangea, Pink Petunia Petunia Poinsettia Abutilon Coleus Dahlia Gerbera Geranium Petunia Chrysanthemum, Garden Cleome Dahlia Geranium Hibiscus, Hybrid Mandevilla Petunia Poinsettia IV Echeveria Agastache Alocasia Duranta Geranium Geranium Pentas 2a What are the symptoms of high substrate ph? Copyright Not for Publication 9

11 Problem Location High ph: Snapdragon Upper (High ph) Upper leaves of snapdragons with interveinal chlorosis. Lower (Low ph) Iron Deficiency High ph (Iron Deficiency) Scaevola Plant sensitive to excessive P, no ! Initial: Slight interveinal chlorosis of recently matured leaf Moderate: Interveinal chlorosis more pronounced, spread to other leaves Advanced: Bleached (white) interveinal chlorosis Possible Causes Iron Deficiency Substrate ph too high Root rot (Pythium, etc check roots) Cold growing Waterlogged conditions Corrections High ph 4 02 Copyright Not for Publication 0

12 2b Low ph Type : Bronzing What are the symptoms of low substrate ph? Three Symptom Types Good Low ph Zonal Geranium Healthy Progression of Iron/Manganese Toxicity Symptoms Low ph Type : Bronzing Lower leaves of marigolds with yellow speckles. Photo by Joshua Henry Type : Low ph Induced Fe/Mn Toxicity Type2: Low ph Severity Zinnia Low ph Copyright Not for Publication

13 Type 2: Low ph (Fe/Mn Toxicity) 2-23 Low ph (Fe/Mn Toxicity) Dragon Wing Begonia ph 5. DW Begonia 2 23 Targeted Tissue Sampling Sample lower leaves to capture micro nutrient levels NC STATE Low ph Low ph Type 3: Stunted Growth Lower # Lime/Yard 3 : Resulting ph: Dry weight Reduction: 59% 29% NC STATE Low ph Type 3: Stunted Growth Corrections Low ph Low ph 4 02 ph: Copyright Not for Publication 2

14 Sub optimal ph Symptoms High ph symptoms Interveinal chlorosis of the new growth Low ph symptoms vary Bronzing of the lower leaves Black speckles of the lower leaves Lack of growth Thus visual symptoms are not always present Know the optimal ph range for each plant Monitor ph to prevent problems 3 How can you determine the substrate ph? ph Monitoring Methods :2 Dilution In house test of using part substrate to 2 parts water SME (Saturated Media Extract) Utilized by most substrate testing labs PourThru A non destructive in house test ph and EC Monitoring PourThru Monitoring Program PourThru Steps PourThru: Smaller Containers Use 6 or 8 inch saucers Irrigate the crop HR prior to PourThru Place a plastic saucer under container Pour enough water over top of substrate to displace ~50 ml of solution Collect and analyze the leachate Copyright Not for Publication 3

15 4 How do you evaluate substrate ph and EC values and correct problems? Parameter ph Optimal Ranges by Group Low (Petunia) General (General) High (Geranium) ph 5.5 to to to 6.5 Goals: Avoiding HIGH ph problems Avoiding LOW ph problems ph Zones: Geranium GRO Zone Tracker App ph Range Target Range Free app for Android or Apple phones, pads, computer Computer based app. Available: Lower Decision Zone Upper Decision Zone Thanks for Attending Questions? Copyright Not for Publication 4

16 Crop & Symptoms Sporadic flowering of Bacopa Four rooted cuttings transplanted in 0 baskets. Prior to shipping buds aborted and flowers senesced Flower and bud abortion Normal buds and flowers Distribution Uniform bud abortion and flower senescence across the crop Information Dark green leaves Flowers appear to be forming, but never fully bloom Fertilization: liquid 200 N ph at 5.8 EC (SME) at.6 ms/cm Hand irrigated No PGRs or pesticides applied after transplant A) Low light B) 2,4 D herbicide C) Drought stress D) Heat stress E) Chemical phytotoxicity Corrective Measures Maintain adequate substrate moisture and do not allow plants to wilt Pinch back the plant will further delay flowering If plants are given adequate water, they should be in full flower within 4 weeks Crop & Symptoms Geranium (interspecific) bud abortion and flower senescence 0 geranium crop with three rooted cuttings Flower and bud abortion Normal buds and flowers Distribution Uniform across the crop, however not all buds are aborting Information Fertilization: liquid 200 N o Additional top dress of CRF ph at 6. EC (SME) at 2.2 ms/cm B nine and Cycocel sprays applied early in production Copyright Not for Publication 5

17 2 2 A) Low light B) Ethephon (Florel/Collate) applications C) Drought stress D) Heat stress E) Chemical phytotoxicity Corrective Measures/Future Remove aborted buds to avoid botrytis Do not apply any other PGRs Plants should be saleable within 5 to 6 weeks Ethephon should only be applied during the first 3 weeks after transplant. All sprays should be applied 6 to 8 weeks prior sale 3 3 Crop & Symptoms Impatiens, geranium, and lily bud abortion and flower senescence Crops grown in a double poly greenhouse on benches and hanging in four layers. Not all crops aborted flowers. Flower and bud abortion Distribution Not uniform across the crop or species Information Geranium leaves turned yellow and white No pesticides applied after transplant Normal buds and flowers 3 3 A) Low light B) 2,4 D herbicide C) Drought stress D) Ethylene from malfunctioning heater E) Chemical phytotoxicity Corrective Measures To avoid ethylene injury, unit heaters need proper ventilation and fresh air from outside Routinely inspect for cracked heat exchanger Routine heater maintenance is essential Tomato plants are good indicator plants to test for ethylene Most plants will recover from ethylene injury Copyright Not for Publication 6

18 4 4 Crop & Symptoms Poinsettia with excessively small bracts Three rooted Prestige poinsettia cuttings transplanted into hanging baskets, pinched and are two weeks from shipping Excessively small bracts Distribution Uniform across the crop Information Fertilization: liquid 250 N ph at 6.0 EC (SME) at.5 ms/cm Early paclobutrazol (Bonzi) drench 4 4 A) High temperatures B) Light pollution C) Low Light D) Early paclobutrazol drench E) Chemical phytotoxicity Corrective Measures/Future Apply BA +GA 4+7 (Fascination or Fresco) at a rate of 3 to 5 20 to 30 days after bract color to increase bract size Always use PGRCalc and check your math when mixing PGRs! 5 5 Crop & Symptoms Calibrachoa baskets with few if any flowers Four rooted cuttings transplanted into each basket. Photograph taken 9 weeks after transplant Few if any flowers Distribution Uniform across the crop Information Fertilization: acid based liquid 200 N ph at 5.7 EC (SME) at 2.0 ms/cm Air temperature of 68/64 F (day/night) Plants were pinched No PGRs applied Copyright Not for Publication 7

19 5 5 A) Low light B) Ethephon (Florel/Collate) application C) Low temperature D) Ethylene from malfunctioning heater E) Drought stress Corrective Measures Remove the excessive shading and give plants 800 to 200 µmol (4000 to 6000 foot candles) Pinch plants back to 3 rd node Do not apply PGRs Plants should be salable within 4 to 5 weeks Michigan Greenhouse Water Sources Well Water Groundwater is made up of rain, springs, and other water applied to soils. The water drains through the soil profile until it reaches a depth where all soil pore spaces are filled. This saturated zone is called the water table or aquifer. Groundwater quality varies because of the parent material, usually rock, that makes up the saturated zone. Well Water After time and with pressure Calcium carbonate becomes limestone Result: Much of the upper Midwest has limestone deposits enters the water supply Measured as alkalinity: essentially watering with lime (increases ph) Copyright Not for Publication 8

20 Well Water In other parts of country, groundwater is drawn from other types of aquifers. SE and NE United States: granite aquifers. Florida: coral aquifers. Depth of well will also affect water quality. Growers have experienced a difference in water quality within a few miles of each other. Factor or element Soluble Salts ph Alkalinity Nitrate NO 3 N Ammonium NH 4 N Total Nitrogen N Phosphorus P Potassium K Calcium Ca Magnesium Mg Sodium Na Chloride Cl Boron B Fluoride F Iron Fe Manganese Mn Sulfur S Copper Cu Zinc Zn Molybdenum Mo Aluminum Al Unit mmhos/cm Michigan Water Actual North Carolina Water Actual NA NA NA NA NA Target 0.2 to to to 60 < 75 < 0 < 30 < to 75 0 to 30 0 to 20 0 to 20 < 0. < < < 0 to 40 < 0. < 0.5 < 0. MSU Water Factor or element Unit Actual Target Soluble Salts mmhos/cm to 0.8 ph to 7.0 Alkalinity** 388* 40 to 60 Nitrate - NO3-N 0 < 75 Ammonium - NH4-N 0 < 0 Total Nitrogen N 0 - Phosphorus - P 0.26 < 30 Potassium - K.59 < 00 Calcium - Ca 95.3* 25 to 75 Magnesium - Mg to 30 Sodium - Na to 20 Chloride - Cl to 20 Boron - B < 0. Fluoride - F.02* < Iron - Fe 0.07 < Manganese - Mn < Sulfur - S to 40 Copper - Cu < 0. Zinc - Zn < 0.5 Molybdenum - Mo 0 < 0. Aluminum - Al 0 - Michigan Water (MSU) Calcium and magnesium are associated with limestone aquifers. 95 Ca. Hardness is often used to describe the level of Ca and Mg in the water. Fluorine is added to water by the city/ water company. Michigan Water (MSU) Concerns: Excess Ca Excess Mg High alkalinity Slightly high Fluoride Yet relatively neutral ph 7.08 This is typical of water when there is a limestone aquifer. Growers in Michigan are essentially watering with liquid lime. Sphagnum Peat Substrates Availability of iron, manganese, zinc, copper, and boron adversely affected by high substrate ph. The generally accepted ph range is 5.8 to 6.2 for the substrate solution. Copyright Not for Publication 9

21 Iron Deficiency due to high substrate ph Rise in Substrate ph What is the major factor influencing the rise of substrate ph? Irrigation water alkalininty Not the irrigation water ph Alkalinity Measure of water s capacity to neutralize acids. buffering capacity of water. Dissolved bicarbonates (HCO 3 ): calcium bicarbonate (Ca(HCO 3 ) 2 ) sodium bicarbonate (NaHCO 3 ) magnesium bicarbonate Mg(HCO 3 ) 2 ) Carbonates (CO 3 ): calcium carbonate (CaCO 3 ) Also can be carbonate ion (CO 3 2 ) Alkalinity Reported as concentration (mg/l = ) or expressed as equivalents of alkalinity (meq/l) Calcium carbonate: meq/l = 50 mg/l Bicarbonate: meq/l HCO 3 = 6 mg/l HCO 3 Water with a high alkalinity will be able to neutralize more acids in the soil than a water with a low alkalinity. Range 0to.5meq <80 (mg/l) HCO 3 Alkalinity.5 to 4 meq 00 to 200 (mg/l) HCO 3 >4meq > 200 (mg/l) HCO 3 Classification Low Marginal High Alkalinity Sometimes water alkalinity can be too low. The water has no buffering capacity and is too pure. Low levels of calcium (Ca), magnesium (Mg), and sodium (Na) may signal low alkalinity. If the alkalinity is too low, then the substrate ph will fluctuate more widely, depending on whether acid or basic fertilizers are used. When substrate ph falls below 6.0 for some crops and 5.5 for most crops, micronutrient toxicities can occur, along with calcium deficiency. Copyright Not for Publication 20

22 Alkalinity Water alkalinity can be determined by titration, which is very easy to do with a commercially available kit. A measured sample of water is treated with a dye that changes color around a ph of 4.5. Acid is added until the dye changes color and the amount of acid is related to the alkalinity. Since titration kits are inexpensive and easy to use, every greenhouse should consider having one. Measuring Alkalinity Effect of Water Alkalinity on Substrate ph Alkalinity If we continually water our plants with high ph water and a high alkalinity the ph of the substrate will increase. Hydrogen ions will be neutralized. What can be done? Acidification of water supply Blend with pond water Acidic fertilizers Alkalinity Acidic Fertilizers Can be used to neutralize < 3 meq of alkalinity High ammoniacal nitrogen may not be appropriate for all crops during in the entire year. Prefer ammoniacal N to be <33% of the total N. Alkalinity Injection of inorganic (mineral) acids is one option for treating high alkalinity irrigation water. Sulfuric, phosphoric, citric, and nitric acids. Recently organic acids, such as Seplex L from GreenCare, have been used to neutralize alkalinity. These organic acids provide safety; but are weaker and may not be as effective when alkalinity is very high. Copyright Not for Publication 2

23 Alkalinity Acids are available in various strengths and degrees of purity. Wear protective clothing and eye guards. Sulfuric acid is commonly available in fairly pure form, 93 % by weight. It produces substantial heat when added to water. Phosphoric acid, usually available at 75 or 85 %, is the least corrosive of the three acids. Nitric acid, available in some areas at 6 %, is quite corrosive and must be handled with great care. Alkalinity When selecting an acid, consider: Ease of use Safety Cost Nutrients (nitrogen, phosphorous, and sulfur) the acid provides Alkalinity How to calculate acid addition rate? You need a customized acid addition rate for YOUR water sample! Acid Addition Calculator (ALK CALC): MSU water modified Fertilizer Target/ Factor or element Unit Actual Target solution acceptable Soluble Salts mmhos/cm to ph to Alkalinity** 388* 40 to Nitrate - NO3-N 0 < Ammonium - NH4-N 0 < Total Nitrogen N Phosphorus - P 0.26 < Potassium - K.59 < Calcium - Ca 95.3* 25 to 75 6 < 50 Magnesium - Mg to < 50 Sodium - Na to < 50 Chloride - Cl to < 40 Boron - B < Fluoride - F.02* <.08 Iron - Fe 0.07 < Manganese - Mn < Sulfur - S to < 00 Copper - Cu < Zinc - Zn < Molybdenum - Mo 0 < Aluminum - Al 0-0 With acidification Alkalinity is reduced Calcium is unchanged Crop & Symptoms Gloxinia with stunted growth Apical meristem death, flower death. Along with a profusion of axillary shoots produced. Top most leaves thick and distorted. Apical Meristem / Flower Death Profusion of Axillary Shoots Copyright Not for Publication 22

24 Distribution Single plant stunted (%), while remainder of the crop has normal growth Information: Plugs purchased from a specialty propagator. No pesticides applied after transplanting ph at 6.5 / EC (PourThru) at 0.67 ms/cm Fertilization: 200 N Upper most fully developed leaf is strap shaped, thick and brittle Tissue Analysis Tissue Analysis Element N % P % K % Ca% Mg % S % Lab Results Interpretation Index 44 L 48 L 5 S 20 E 8 H 53 S Element N % P % K % Ca% Mg % S % Lab Results Interpretation Index 44 L 48 L 5 S 20 E 8 H 53 S Element Fe Mn Zn Cu B Lab Results Interpretation Index 46 L 50 S 53 S 42 L 6 S Element Fe Mn Zn Cu B Lab Results Interpretation Index 46 L 50 S 53 S 42 L 6 S A) Boron Deficiency B) PGR Overdose C) Broad Mites D) 2,4 D Herbicide E) Chemical Phyto Tissue Analysis Element N % P % K % Ca% Mg % S % Lab Results Interpretation Index 44 L 48 L 5 S 20 E 8 H 53 S Element Fe Mn Zn Cu B Lab Results Interpretation Index 46 L 50 S 53 S 42 L 6 S Copyright Not for Publication 23

25 2 Corrective Procedures: Boron Deficiency Discarding plant is the best option. Severe distorted growth can not be reversed. Not economically feasible to cut back plant and regrow. Crop & Symptoms Tomato with distorted growth New growth (top most leaves) thick and distorted (curling). Older Growth Normal Distorted New Growth 2 2 Distribution Most plants stunted (>95%), with distorted new growth. Symptoms more severe closer to the air intake side Information: Plants growing normally for 4 weeks Symptoms appeared over a few days as new growth elongated ph at 5.8 / EC (SME) at.29 ms/cm Fertilization: 50 N Distorted growth and a proliferation of secondary shoots occurring too. 2 2 Leaf curling, thickening of the new growth also observed. A) Boron Deficiency B) PGR Overdose C) Broad Mites D) 2,4 D Herbicide E) Chemical Phyto Copyright Not for Publication 24

26 2 3 Corrective Procedures: 2,4 D Herbicide Discarding plant is the best option. Severe distorted growth can not be reversed. Not economically feasible to cut back plant and regrow. Crop & Symptoms Ivy with distorted new growth New growth is distorted and smaller is size. Oldest growth is normal, but there is a clear transition between good and distorted growth. Normal Growth Stunted Growth 3 3 Distribution Most plants (~00%) exhibit a degree of distortion. All cuttings came from the same stock plant and were propagated on site. Other plants in the greenhouse do not exhibit any symptoms. Information: Plants growing on the same irrigation row for 4+ months No pesticides applied after transplanting ph at 5.8 / EC (PourThru) at 0.78 ms/cm Periodic fertilization: 00 N Clear transition between normal growth and distorted growth is visible. 3 3 A) Boron Deficiency B) PGR Overdose C) Broad Mites D) 2,4 D Herbicide E) Chemical Phyto Broad Mites Can use a 00X microscope to look for eggs for identification Eggs Female Adult Matt Bertone Insect ibook Copyright Not for Publication 25

27 3 4 Corrective Procedures: Broad Mites Apply pesticide to control mites early in production. Severe distorted growth can not be reversed. Not economically feasible to cut back plant and regrow. Discarding plant is the best option. Crop & Symptoms Stunted growth of ageratum After plugs transplanted, some plants grew normally, while others were stunted and darker green in color. Normal Growth Stunted Growth Distribution Most plants stunted (80%), with dark green, crinkled leaves Some plants have normal growth Extra plugs from the same plug tray transplanted into 203 cell packs (and grown in another greenhouse 3 miles away) same symptoms occurred. Information: Plugs purchased from a specialty propagator. No pesticides applied after transplanting ph at 6. / EC (SME) at.43 ms/cm Fertilization: 50 N A) Boron Deficiency B) PGR Overdose C) Broad Mites D) 2,4 D Herbicide E) Chemical Phyto 4 5 Corrective Procedures: PGR Overdose Fascination / Fresco foliar sprays may help overcome an anti GA type PGR overdose, if applied early. With severe cases of PGR overdose, the only option is to discard plants Crop & Symptoms Lobularia Snow Princess with shoot dieback and distorted growth. Over the course of 2 weeks, tip dieback occurred. New growth which develops from the plant base is stunted. Tip Dieback Research Reports #205 02v # Distorted Growth Copyright Not for Publication 26

28 5 5 Distribution All lobularia plants (00%) exhibit dieback. Other species in greenhouse do not exhibit symptoms. Information: Plugs purchased from a specialty propagator. Plants appear normal for the first 4 weeks of growth. Conserve and Judo applied for thrips control. ph at 6.0 / EC (PourThru) at.07 ms/cm Fertilization: 50 N (3 2 3 Cal Mag) New growth that develops is distorted and stunted. 5 5 A) Boron Deficiency B) PGR Overdose C) Broad Mites D) 2,4 D Herbicide E) Chemical Phyto Chemical Phyto Judo Lobularia Kontos Geraniums Ethephon Geraniums Distance Poinsettia 5 Corrective Procedures: Chemical Phyto No options available. The time required to regrow normal leaves is too long. Note label cautions of plants to avoid before applying pesticides. SUBMITTING SAMPLES TO DIAGNOSTIC LABS Copyright Not for Publication 27

29 SUBMITTING SAMPLES TO DIAGNOSTIC LABS SUBMITTING SAMPLES TO DIAGNOSTIC LABS Early Communication Contact the diagnostic lab and let them know that you are sending a sample and the tracking number of the package, if appropriate. This will help the diagnostic lab to know when to expect the package and also how to handle it appropriately. How to Collect Specimens Send entire plants or generous amount of material, if available. Including roots and some substrate. Plants with root and crown rot diseases cannot be properly diagnosed unless root and crown tissue is submitted. Submit plants with symptoms that are in varying stages of decline. Avoid sending only dead plants. SUBMITTING SAMPLES TO DIAGNOSTIC LABS SUBMITTING SAMPLES TO DIAGNOSTIC LABS How to Ship Specimens Plugs/Seedlings: It is tricky to get plugs submitted to the lab in good condition. Leave the plugs in the tray for shipping purposes. Entire trays are not required; a section of the tray can be cut and shipped. Submit a minimum of 2 plugs. Wrap the plug tray in newspaper or add packing material that will prevent plugs from being dislodged from the tray. This plant material degrades fairly quickly; as a result plants should be dropped off in person or sent overnight shipping. How to Collect Specimens Do not add wet paper towel or other sources of moisture when packaging. Plant material should be wrapped in dry newspaper and then placed in a plastic bag to preserve the integrity of the sample. When root tissue is included, wrap the root balls in plastic to prevent the soil from coming in contact with the foliage. Place insects samples in vials. SUBMITTING SAMPLES TO DIAGNOSTIC LABS SUBMITTING SAMPLES TO DIAGNOSTIC LABS How to Submit Specimens Almost all samples should be shipped in a crush proof container (ie. box), rather than an envelope immediately after collecting. Leaves and stems that are pressed and mailed in envelopes do not arrive in good condition. Include a completed copy of the submittal form, put the form in a separate re sealable bag to prevent it from getting damp or soiled. How to Ship Specimens If holdover periods are encountered, keep specimen cool. Mail packages to arrive on weekdays. Do not mail or ship samples on Friday, as most labs are not open on weekends. Send samples with priority or express delivery so they are received in the best condition possible. Shipping containers/materials are not returned to clients unless previous special arrangements are made. Copyright Not for Publication 28

30 SUBMITTING SAMPLES TO DIAGNOSTIC LABS SUBMITTING SAMPLES TO DIAGNOSTIC LABS How to Ship Specimens Incomplete information or poorly selected specimens may result in an inaccurate diagnosis or inappropriate control recommendations. Badly damaged specimens are often unidentifiable and additional sample requests can cause delays. Please double bag out of state samples to prevent escape of pathogens/pests during shipping. (ex. two zip lock freezer bags). MSU and Purdue labs have USDA APHIS permits in place to accept samples from the continental U.S. How to Ship Specimens Incomplete information or poorly selected specimens may result in an inaccurate diagnosis or inappropriate control recommendations. Badly damaged specimens are often unidentifiable and additional sample requests can cause delays. Please double bag out of state samples to prevent escape of pathogens/pests during shipping. (ex. two zip lock freezer bags). MSU and Purdue labs have USDA APHIS permits in place to accept samples from the continental U.S. SUBMITTING SAMPLES TO DIAGNOSTIC LABS Fill out form completely!! Michigan State University Diagnostic Services 578 Wilson Rd. East Lansing, MI Office: Fax: d.msu.edu Purdue Plant and Pest Diagnostic Laboratory LSPS Room 6, Purdue University 95 W. State Street West Lafayette, Indiana Office: Fax: Summary Problem Diagnostics Observe Gather information Use references Base conclusions on available facts Know how to identify and correct them. e GRO Alerts available for additional information e-gro Alert Problem Updates Thanks for Attending Questions? Copyright Not for Publication 29