Relationship Between Mineral Nutrition of Plants and Disease Incidence Don M. Huber

Similar documents
Potassium and Phosphorus as Plant Nutrients. Secondary Nutrients and Micronutrients. Potassium is required in large amounts by many crops

Managing Fusarium Diseases of Vegetables

Soil acidity. Kiyoshi Tsutsuki

MICRO NUTRIENTS AND SECONDARY NUTRIENTS

Essential Soil Nutrients for Plant Growth and Development

BOTANY AND PLANT GROWTH Lesson 9: PLANT NUTRITION. MACRONUTRIENTS Found in air and water carbon C oxygen hydrogen

Role of Phosphorus, Potassium, Calcium and Magnesium on Disease Resistance. Overview. - Introduction. - Conclusions / prospects

Terry Richmond s Fertilizer Package mentioned in the panel discussion March 14, 2013.

Mineral Nutrition Contributes to Plant Disease and Pest Resistance 1

SOIL AND PLANT NUTRITION

Plant Food. Nitrogen (N)

Plants, soil, and nutrients. Created in partnership with Alex Lindsey, Ph.D., The Ohio State University

LECTURE 12 NUTRIENT DEFICIENCY AND TOXICITY. Causes and Symptoms. Nitrogen

Chapter 7: Micronutrient Management

Soils and Soil Fertility Management

Interpreting Soils Report. Beyond N P K

Plant Nutrients in Mineral Soils

Animal, Plant & Soil Science. D3-7 Characteristics and Sources of Secondary Nutrients and Micronutrients

Mineral Nutrition of Fruit & Nut Trees. Fruit & Nut Tree Nutrition 3/1/2013. Johnson - Nutrition 1

Soil Composition. Air

INTRODUCTION TO VISCOFOL. Revolutionary high viscosity foliar feeds

How to Develop a Balanced Program for Pecan and Chili. Robert R Smith

Early Detection of Nutrient Deficiencies and Toxicities

Botany & Plant PathologyPurdue University, West Lafayette, IN, USA 2. Institute of Plant Nutrition and Soil Science, Braunschweig, Germany

Multi-K. Potassium Nitrate Products For Healthy Crops

Unit B: Seed Germination, Growth, and Development. Lesson 4: Determining Nutrient Functions and Utilization

Soil Nutrients and Fertilizers. Essential Standard Explain the role of nutrients and fertilizers.

1

Fetrilon Combi 1/ Fetrilon Combi 2/ Hortrilon

Interpreting Plant Tissue and Soil Sample Analysis

Fertilization Programming

MEASURE AND MANAGE. Zinc. By Dale Cowan Agri-Food Laboratories CCA.On

Basafer Plus/Fetrilon / Zitrilon /Mantrilon

Potash Phosphate Nitrogen

Preventing, diagnosing and understanding nutrient deficiencies in plants

Greenhouse Horticulture

Foliar Micronutrients for Broad Acre Crops Higher yield and better quality Balanced trace element supply for healthy crops Insurance against

Nutrients & Diagnosing Nutrient Needs. Carrie Laboski Dept. of Soil Science UW-Madison

Sulphur Fertilizer Effect on Crop Development & Quality

DOMOGRAN 45 ACTIVATING YOUR NUTRIENT POTENTIAL THE NITROGEN-SULFUR FERTILIZER FROM LEUNA

Nutrient Deficiencies and Application Injuries in Field Crops

Understanding a Soil Report

Plant, Soil, and Nutrients

Supplying Nutrients to Crops

SOIL MICRONUTRIENTS: FROM B to Z. Scott J. Sturgul 1. Introduction

and biocontrol activity of microorganisms for sustainable agriculture

Recommended Resources: The following resources may be useful in teaching this lesson:

AGVISE Laboratories Established 1976

REMEMBER as we go through this exercise: Science is the art of making simple things complicated!

What is NUTRIO? Product Line for Biologically Active Products. Biologically Derived Products. Microbial Inoculants

Micronutrient Management. Dorivar Ruiz Diaz Soil Fertility and Nutrient Management

Essential Elements. Original research don by Julius von Sachs 1860 using hydroponics

Interpretation of Soil Tests for Environmental Considerations

Nutrient Recommendations Agronomic Crops Last Updated 12/1/16. Grain Corn. Crop Highlights Target ph: 6.0

Managing Micronutrients with Soil (Plant) Testing and Fertilizer

Fertilizer. Fertilizers. (FAO press release, April 1990): Nutrient Depletion. Nutrient Depletion 4/16/2012

Monica Ozores-Hampton University of Florida/IFAS/SWFREC Spring 2013

DAFFODILS ARE WHAT THEY EAT: NUTRITIONAL ASPECTS OF SOILS

BIOZYME is a product in use by Latin American farmers in a wide range of crops to provide outstanding results for more than 18 years.

Micronutrient Requirements of Crops

Nutrition of Horticultural Crops. Monica Ozores-Hampton University of Florida/IFAS/SWFREC Spring 2013

Management of Fusarium and other Soil Borne Diseases in Tomatoes and Vegetables

Soil fertility & fertilizers. Soil Nutrients. Soil Nutrients. by Jeff Choate

12. ZINC - The Major Minor

Limitations to Plant Analysis. John Peters & Carrie Laboski Department of Soil Science University of Wisconsin-Madison

Minerals, Trace Elements and Enzymes. Dan Kittredge

Nutrient management irrigated corn. Jim Camberato

Barley and Sugarbeet Symposium

Raymond C. Ward Ward Laboratories, Inc Kearney, NE

Visit For All NCERT solutions, CBSE sample papers, Question papers, Notes for Class 6 to 12. Chapter-12 MINERAL NUTRITION

IRON. AGRITOPIC August INTRODUCTION 2. IRON IN THE SOIL

SOILS AND PLANT NUTRITION

SILICON FERTILIZERS 2019

FACTORS AFFECTING WATER QUALITY

Role of Micronutrients in Plant Resistance to Diseases. by Ismail Cakmak Sabanci University-Istanbul

Specialists In Soil Fertility, Plant Nutrition and Irrigation Water Quality Management.

Nitrophoska. Cereals, fodder beet, horticulture, maize and vegetables. Precise nutrition for superior plant performance

Technical Guide on Nutritional recommendations for SWEETPEPPER For Open-field, Nethouse, Tunnels and Polyhouse

Mineral Nutrition. Criteria for Essentiality

Use of Soil and Tissue Testing for Sustainable Crop Nutrient Programs

Soil organic matter composition, decomposition, mineralization and immobilization

Bioavailability of Cd to Food Crops in

XI CLASS BIOLOGY CHAPTER 12: MINERAL NUTRITION

Teff Compendium Nutrient deficiency symptoms SINCE

Plants Essential Elements. Macro and Micronutrients

Effect of Macro & Micro Nutrients on Occurrences of Fusarium Wilt (Fusarium oxysporum) in Tomato (Lycopersicon esculentum Mill.)

Dry Bean Fertility Dave Franzen NDSU Soil Science Specialist

Vegetable Update 2013

Nutrient level (EC) in a pot is like a bank

Mineral Nutrients and their functions in plants

Water Soluble Fertilizer for Foliar Application

Chapter 1: Overview of soil fertility, plant nutrition, and nutrient management

INTERPRETATION GUIDE TO SOIL TEST REPORTS

Nutrient Management. Ontario Certified Crop Adviser Pre-Exam Workshop Woodstock, Ontario 20 January 2014

Soybean Soil Fertility

PRIMARY (MACRO) NUTRIENTS

Amelia Agrochemical Products Available for Licensing PRODUCT LIST

ABOUT TURF FORMULA. 36% Decrease in Brown Patch 35% Increase in Root Mass 33% Nematode Reduction 73% Salt Reduction in 90 Days

Essential plant nutrients. Classification of essential plant nutrients

Product Name : Fish s Amino Nutrients

Transcription:

Relationship Between Mineral Nutrition of Plants and Disease Incidence Don M. Huber Botany & Plant Pathology Department Purdue University, West Lafayette, IN USA E-mail: huber@btny.purdue.edu

Disease can alter plant nutrition Availability Impaired utilization Mobilization Frenching of Tobacco caused by Bacillus cereus (Mn toxicity) Nutrition can alter Disease severity - zinc + zinc Effect of Zn sufficiency on Rhizoctonia winter-kill of wheat

Effects of Disease on Plant Nutrition Disease Type Root rots, damping-off, insects, nematodes Maceration (rot) diseases Vascular wilts, leaf spots Galls, brooms, over-growth Viruses Fruit & storage rots Effect on Plant Nutrition Immobilization, absorption and distribution Distribution ( sinks ), depletion, change metabolism Translocation, distribution, efficiency Distribution ( sinks ) metabolic efficiency Sinks, depletion, metabolic efficiency Sinks, distribution, nutrient reserves

Reports of Vegetable Diseases Influenced by Nutrients Effect on Diseases Disease Increase Reduce Total Bacterial 22 34 56 Fungal 79 191 270 Virus 19 19 38 Nematode 10 12 22 Total 130 256 386* *About 4% are reported to both increase or decrease depending on the situation

Reported* Effects of Nutrients on Disease Disease is: Mineral element Decreased Increased Variable Nitrogen (N/NH 4 /NO 3 ) 168 233 17 Phosphorus (P) 82 42 2 Potassium (K) 144 52 12 Calcium (Ca) 66 17 4 Magnesium (Mg) 18 12 2 Manganese (Mn) 68 13 2 Copper (Cu) 49 3 0 Zinc (Zn) 23 10 3 Boron (B) 25 4 0 Iron (Fe) 17 7 0 Sulfer (S) 11 3 0 Other (Si, Cl, etc.) 71 6 8 *Based on 1,200 reports in the literature.

Effect of the form of Nitrogen on Potato Diseases Disease Source Rhizoctonia Verticillium Yield Percent of N Canker Wilt (kg/ha) No. 1 (NH 4 ) 2 SO 4 6.2 a 3.9 b 32,670 69 a Ca (NO 3 ) 2 4.8 b 9.4 a 21,340 57 b

EACH ELEMENT FUNCTIONS AS PART OF A DELICATELY BALANCED INTERDEPENDENT SYSTEM WITH THE PLANT S GENETICS AND THE ENVIRONMENT Ca, Mg, S, Fe, Mn P N Cu, Zn, B, Mo, I K Nutrient Balance is Important

INTERACTING FACTORS DETERMINING DISEASE SEVERITY Vigor, Stage of Growth, Root Exudates Resistance PLANT Susceptibility PATHOGEN Population Virulence Activity TIME BIOTIC ENVIRONMENT Antagonists, Synergists Oxidizers, Reducers Competitors, Mineralizers ABIOTIC ENVIRONMENT Nutrients Moisture Temperature ph (redox potential) Density, gases

Implications of Nutrition in Disease Verticillium wilt of potato Ammonium Observed effects of mineral amendment on disease severity Comparison of plant tissue levels of resistant and susceptible plants Nitrate Comparison of plant tissue levels of diseased and non-diseased plants Association of conditions affecting a specific nutrient with differences in disease Manured Not manured Rhizoctonia winter-kill of wheat A combination of the above

EFFECT OF MINOR ELEMENTS ON YIELD OF TAKE-ALL INFECTED WINTER WHEAT Minor Element Wheat Variety AUBURN BEAU ---------kg/ha------- None 2,950 2,750 Cu 2,750 2,880 Fe 2,950 2,880 Mg 3,250 2,880 Mn 3,750 3,350 Zn 2,950 2,880 Minor elements co-injected with NH3 + nitrapyrin; sandy loam soil

Correlation of Tissue Zn with Rhizoctonia "winter-kill * Tissue Zinc % Plant Kill Condition Without With(in) Without With(in) ---------------------------------------------------------------------------------------- Barnyard Manure 20 41 80 15 Sediment Area 17 27 100 45 Tree Leaf-drop Area 19 34 65 20 ----------------------------------------------------------------------------------------- Sufficiency Level: 20-150 mg/kg ----------------------------------------------------------------------------------------- *Caused by Rhizoctonia cerealis

EFFECT OF AN OAT PRECROP Tissue Disease Yield CROP SEQUENCE Mn Index* (kg/ha) Wheat-Wheat-Wheat 20 4.2 1,450 Wheat-Oats-Wheat 55 1.8 3,900 Oats-Oats-Wheat 76 1.0 4,160 *Take-all root & crown rot: 0 = no infection, 5 = dead (white heads)

Factors Affecting Mn Availability and Severity of Some Diseases* Soil Factor or Effect on: Cultural Practice Mn Availability Disease Severity Low Soil ph Increase Decrease Green Manures Increase Decrease Ammonium Fertilizers Increase Decrease Irrigation Increase Decrease Firm Seed bed Increase Decrease Nitrification Inhibitors Increase Decrease Soil Fumigation Increase Decrease Metal Sulfides Increase Decrease High Soil ph Decrease Increase Lime Decrease Increase Nitrate Fertilizers Decrease Increase Manure Decrease Increase Low Soil Moisture Decrease Increase Loose Seed bed Decrease Increase *Potato scab, Rice blast, Take-all, Phymatotrichum root rot, Corn stalk rot

EFFECT OF SOME CULTURAL PRACTICES ON TISSUE Mn & TAKE-ALL CULTURAL CONDITION Mn* Take-all** Loose Seedbed 11.2 3.5 Firm Seedbed 19.3 2.8 Wheat Precrop 21.0 4.3 Oat Precrop 45.0 1.8 Nitrification 8.9 3.5 Inhibiting Nitrification 17.2 2.4 *Mn Sufficiency Range is 20-150 mg/g **Disease index: 1 = no infection; 5 = dead (white-head)

ENVIRONMENTAL GROUPINGS LOW-HIGH ph High ph Diseases - Increased by Oxidizing Conditions Low ph Diseases - Increased by Reducing Conditions FORM OF NITROGEN Diseases Favored by Nitrate - Increased by Oxidizing Diseases Favored by Ammonium - Increased by Reducing MICRONUTRIENT Diseases Reduced by Mn, Fe, S - Increased by Oxidizing Diseases Reduced by Ca, Zn, Mg - Increased by Reducing

Relationship of Nutrition with Disease 1. Genetics of the Plant 2. Nutrient Form or Availability 3. Rate Applied or Available 4. Method and Time Applied 5. Source of Element & Associated Ions 6. Integration with other practices

Relationship of Nutrition with Disease 1. Genetics of the Plant Immunity<-->Resistance<-->Tolerance<-->Susceptibility [Nutrient uptake efficiency, nutrient availability] Normal corn Glyphosate resistant corn Normal soybean Glyphosate resistant soybean Difference in Mn Uptake efficiency: Rye is more efficient than wheat Take-all of: Wheat after wheat (front) versus Wheat after oats (back) Effect of the glyphosate resistance gene on Mn uptake efficiency

NUTRIENT UPTAKE EFFICIENCY Root Uptake Kinetics Root Morphology Siderophore Production Microbial Activity in rhizosphere

Transcient foliage chlorosis of soybeans after applying glyphosate on a low Mn soil [banded to show effect]

Relationship of Nutrition with Disease 2. Nutrient Form or Availability Oxidized <--> Reduced, Soluble <--> Non-soluble Inhibition of Nitrification Organic Nitrogen Nitrous oxides Denitrification Ammonium Nitrite Nitrate Urea Leaching Nitrogen, Iron, Manganese, Sulfur

INFLUENCE OF THE FORM OF NITROGEN PHOTOSYNTHESIS CHO + H + NO3 = Amino Acids CHO + NH4 = Amino Acids Acid Rhizosphere NO3 Alkaline

Some Diseases Reduced by N03, High ph Crop Disease Pathogen Asparagus Wilt Fusarium Bean Chocolate Spot Botrytis Root Rot Fusarium Root Rot Rhizoctonia Beet Damping Off Pythium Cabbage Club Root Plasmodiophora Yellows Fusarium Celery Yellows Fusarium Corn Ear rot F. moniliforme Cucumber Wilt Fusarium Pea Damping-Off Rhizoctonia Pepper Wilt Fusarium Potato Stem Canker Rhizoctonia Tomato Gray Mold Botrytis White Mold Sclerotinia S. Blight Sclerotium Wilt Fusarium

Diseases Reduced by NH4, Low ph Crop Disease Pathogen Bean Root Rot Thielaviopsis Root Knot Meloidogyne Carrot Root Rot Sclerotium Corn Stalk rot Gibberella Egg Plant Wilt Verticillium Many Root rot Phymatotrichum Onion White Rot Sclerotium Pea Root Rot Pythium Potato Scab Streptomyces Wilt Verticillium Virus Potato Virus X Rice Blast Magnaporthe Tomato S. Wilt Pseudomonas Anthracnose Colletotrichum Wilt Verticillium Virus Potato Virus X Wheat Take-all Gaeumannomyces

Effect of N Form on Yield of Verticillium Infected Potato Metric Ton per Hectare Potatoes 0 30.00 32.50 35.00 37.50 40.00 42.50 45.00 Yield Non-Treated Control Telone Fumigated Telone + NH 4 -N Telone + NO 3 -N 33.55 40.15 43.45 36.41

90 kg/ha N applied 90 kg/ha N + a nitrification Inhibitor applied Effect of inhibiting nitrification of ammonia on take-all of wheat

Effect of Inhibiting Nitrification on Scab of Potato Disease scale: 0 = no surface scab, 2 = 10% surface scab, 6 = 30% scab. Ammonium N with a nitrification inhibitor Ammonium N without inhibiting nitrification Nitrate nitrogen

Relationship of Nutrition with Disease 3. Rate Applied or Available Amount available Deficiency to sufficiency versus Sufficiency to excess for the particular plant Time available Nutrient balance Deficient Sufficient Excess

Effect of Nitrogen Rate on Take-all Root and Crown Rot of Wheat Soil Type Sand Sandy Loam N rate Yield %White heads Yield % White heads None 1,270 30 938 50 45 1,540 26 2,350 23 90 1,680 18 3,150 19 135 2,550 12 3,220 20

Relationship of Nutrition with Disease 4. Method and Time Applied Soil <--> Seed <--> Foliage, Side-dress <--> Band <--> Broadcast Spring <--> Fall <--> Split Susceptibility of Plant, Favorable Environment, Virulence of Pathogen Effect of nitrogen source on Rhizoctonia winter-kill of winter wheat Nitrogen Treatment Time Percent Kill NH 3 + N-Serve September 14 Urea Granuals February 40 28% N Solution February 60 Urea April 14

Late winter top-dress Fall preplant + nitrification inhibitor Effect of Time of Nitrogen Application on Rhizoctonia Winter-Kill of Wheat

Effect of Application Method on Mn Availability & Take-all of Wheat Method Availability Take-all effect Broadcast Poor None (Rapidly oxidized & immobilized) Band Fair Positive (Limited to the Band) Foliar Good Secondary (Not translocated downward) Seed Good Positive (but available only for seedling)

Relationship of Nutrition with Disease 5. Source and Associated Ions Gas <--> Liquid <--> Granule, Anion <--> Cation (K 2 SO 4 /KCl) EFFECT OF NITROGEN SOURCE ON RHIZOCTONIA OF WINTER WHEAT Nitrogen Treatment Time Percent Kill -------------------------------- ------------------- ------------------- NH 3 + N-Serve September 14 Urea Granuals February 40 28% N Solution February 60 Urea April 14

Relationship of Nutrition with Disease 6. Integration with other practices Rotation, Tillage, Seed rate, Herbicide, ph, Moisture No press wheel Press wheel Severe take-all of wheat following glyphosate on soybeans (left), the non-treated control is right. Less take-all of wheat in a firm (right) than loose seed-bed (left)

Mechanisms by which Nutrients Reduce Disease Increased Plant Resistance Physiology - phytoalexin, CHO, phenolic production Defense- callus, lignituber, cicatrix formation Disease Escape Increased growth - roots, leaves Shortened Susceptible stage Increased Plant Tolerance Nutrient sufficiency Compensation Inhibited Pathogen Activity Reduced virulence Survival, multiplication Biological control

Effect of Mn on Root Penetration % of Roots Penetrated to the Steele 100 [Take-all] 80 60 40 20 0 NONE PRECULTURE CULTURE BOTH Time Manganese is Applied

VIRULENCE FACTORS OF PATHOGENS Immobilization/mobilization of nutrients Blast, take-all, frenching Physical wounding Fungi and nematodes Maceration - necrosis Bacterial and fungal enzymes Vascular plugging Bacterial gums and Fungal enzymes Stimulation of physiology & excess growth Hormones, genetic transformation Toxins Pyricularin, alpha picolinic acid, etc. Combination

EFFECT OF NITROGEN FORM ON ENZYMES OF RHIZOCTONIA SOLANI Nitrogen Form Enzyme(s) NH 4 NO 3 Cellulase* Polygalacturonase** Pectin transeliminase** + --.3230.0088.0817.0083 *Cellulose membrane decomposition **Viscosity reduction (V.R./mg protein)

RHIZOSPHERE INTERACTIONS Population of Oxidizers or Reducers Tolerant vrs Susceptible Wheat to Take-all Tolerant vrs Susceptible Tobacco to Frenching Tolerant vrs Susceptible Plants to Crown Gall Biological Control - Plant Growth Promotion Oats Resistant to Take-all Glycocyanide Root Exudates toxic to Oxidizers Siderophore Production Plant (Rye versus Wheat)(Melons vrs Wheat) Fe, Mn, etc. Immobilization or Solubilization Configuration of Root System Susceptible vrs Tolerant Cotton Tap Root vrs heighly branched

MECHANISM OF ACTION PREDISPOSITION Nutrient Stress Physiological Regulation VIRULENCE Over come plant defenses Production of extra-cellular enzymes PATHOGENESIS Compromise plant defenses Membrane permeability Physiologic regulation

USING NUTRIENTS FOR DISEASE CONTROL Modify Availability - Fertilizing (amending) - Changing the environment ph, tillage, seed bed, crop rotation, etc. - Microbial enrichment (PGPR) Modify Uptake - Improve cultivar efficiency Root morphology Siderophore production Rhizosphere influence - Improve Cultivar Tolerance

CHANGING REACTIONS Modify the Environment Organic amendments (manure) Crop sequence Inorganic amendments (Liming vrs Sulfur) Fertilization Moisture control (Flood falowing, etc.) Modify the Plant Insensitivity to microbial metabolites Siderophore production Root exudates Modify the Microflora Biological control - PGPR Inhibit nitrification

Changing the Biological Environment % NO3 Effect of crop residues on nitrification 100-90 - 80-70 - 60-50 - 40-30 - 20-10 - 0 - Soybean Alfalfa Pea Corn 0 1 2 3 4 5 6 7 8 Weeks Incubation Fallow Wheat Oat Trachypogon Barley Conifers

Factors Affecting Mn Availability and Severity of Potato Scab Soil Factor or Cultural Practice Effect on: Mn Availability Scab Severity Low Soil ph Increase Decrease Green Manures Increase Decrease Ammonium Fertilizers Increase Decrease Irrigation Increase Decrease Firm Seed bed Increase Decrease Nitrification Inhibitors Increase Decrease Soil Fumigation Increase Decrease Metal Sulfides Increase Decrease High Soil ph Decrease Increase Lime Decrease Increase Nitrate Fertilizers Decrease Increase Manure Decrease Increase Low Soil Moisture Decrease Increase Loose Seed bed Decrease Increase

Fusarium Root Rot of Bean Caused by F. solani fsp. phaseoli Loss from: Root and hypocotyl rot Control: Crop sequence Nitrate-N

CROP SEQUENCE, FUSARIUM, BEAN ROOT ROT & Yield Maize-Bean Beets-Bean Wheat-Bean Relative Effect 0 10 20 30 40 50 60 70 80 90 100 Fusarium Population Root Rot Index Seed Yield Fusarium Population Root Rot Index Seed Yield Fusarium Population Root Rot Index Seed Yield Barley-Bean Fusarium Population Seed Yield Root Rot Index

EFFECT OF SEED TREATMENT WITH VARIOUS SPECIES OF BACILLUS ON WHEAT YIELDS t/ha 2.5 CONTROL BACILLUS spp. B. CEREUS B. MEGATERIUM B. SUBTILIS B. PUMILUS 2.0 1.5 1.0 After DB Scott, 1995 Isolates of different bacterial species

NUTRIENT MANAGEMENT must: Meet Potential Crop Needs Use Best Management Practices Rate and form of application Time of application Be Economically Feasible Include Essential Pest Control Be Environmentally Sound

Corn Stalk Rot, caused by Gibberella zeae and other fungi Cost farmers $ 8-10 billion a year Stalk rot is one of the most important soilborne diseases of corn

Losses Occur Through Reduced yield Lower grain quality Increased harvest costs Reduced production efficiency

Nitrate or ammonium Nitrogen is the driving force Nitrate, amide, amino acids, proteins Nitrate, amino and amide compounds

EFFECT OF NITROGEN STRESS During grain-fill plants cannibalize: 1. Storage nitrogen (Recycle) 2. Physiological nitrogen (enzymes) Rubisco Pep Carboxylase 3. Structural proteins Glycoprotein (hydroxyproline) in cell walls

EFFECTS of NITROGEN on STALK ROT Nitrogen Rate: Reduces stalk rot up to full sufficiency Excess nitrogen increase stalk rot Nitrogen Form: Ammonium reduces stalk rot through Nitrogen efficiency Physiological interactions

PREDISPOSITION TO STALK ROT: A CARBON OR NITROGEN DEFICIENCY CARBON: Senescence when photosynthesis stops Low carbohydrate reserves increase NITROGEN: Rate response up to sufficiency (Maintains photosynthesis) Excess increases Ammonium reduces (form effect) Stay green hybrids are more tolerant

Effect of Inhibiting Nitrification on Rubisco Activity 120 # N/acre 120 # N/acre + Nitrapyron 30 Days Post Pollination Hybrid: B73xMo17

Rice blast, caused by Pyricularia grisea (Magnaporthe grisea) Costs farmers $ 5 billion a year Blast is one of the most important diseases worldwide because rice is a major source of food for 60% of the world s population

Rice blast, caused by Pyricularia grisea (Magnaporthe grisea)

Effects of Cultural Conditions on Mn Availability & Blast Condition Manganese availability Blast severity Upland rice culture Decrease Increase Alkaline soils Decrease Increase Nitrate nitrogen Decrease Increase Aerobic or dry soils Decrease Increase Low temperatures Decrease (uptake) Increase Sandy soil Decrease Increase Manure Decrease Increase High plant populations Decrease Increase Paddy rice culture Increase Decrease Acid soils Increase Decrease Ammonium nitrogen Increase Decrease Inhibiting nitrification Increase Decrease Anaerobic soils Increase Decrease High temperatures Increase Decrease Silicon fertilization Increase Decrease Clay & loam soils Increase Decrease

A PROPOSED ROLE OF Mn IN BLAST PATHOGENESIS RESISTANCE (Mn oxidation blocked) Spore Germination & Appresorium formed Toxin Formed (chelator) Localized Mn oxidation* Penetration Mn available for pathogen (immobilized for plant) Plant defenses compromised Induced Mn deficiency Pathogenesis AVIRULENCE (Unable to oxidize Mn) * Not seen with mechanical wounding Cell death (necrosis) Mn 4+ accumulates in lesions Sporulation as Mn 2+ depleted by oxidation, ppt. Chlorosis of adjacent tissue Mn depleted in cells adjacent to lesion below threshold for photosynthesis

Take-all Root, Crown, and Stem Rot of Cereals Caused by Gaeumannomyces graminis var tritici

MANGANESE AVAILABILITY AND MICROBIAL ACTIVITY ph: Acid < 5.5 Biological > 7.8 Alkaline Mn Form: Mn++ Activity Availability: Available Mn++++ Not Available

A Gaeumannomyces graminis A. Runner hyphae on wheat root B. Oxidation of Mn in media C. Oxidation of Mn in soil B C

Effect of an Oat Precrop on Take-all Tissue Disease Yield Crop Sequence Mn Index (kg/ha) Wheat-wheat-wheat 20 4.2 1,450 Wheat-oats-wheat 55 1.8 3,900 Oats-oats-wheat 76 1.0 4,160

APPROACHES TO IMPROVE DISEASE CONTROL Mn Seed Content Mn Uptake Efficiency Root Exudate Effects Plant SOIL Mn Amendment Mn Seed Treatment ph Adjustment Cultural Modification Nutrient Balance MICROBES Mn Reducers Inhibit Nitrifiers

Fusarium Wilt/Yellows Disease Disease of fruit, vegetable, fiber Increased with ammonium-n Severe in low (acid) ph soils Control: Adequate liming PLUS nitrate-n (Decreases Mn and Fe availability) and ornamental crops

Wilt/Yellows Diseases Caused by Fusarium oxysporum Plant Disease Pathogen Asparagus Wilt F. oxysporum f. sp. asparagi Bean Yellows F. oxysporum f. sp. phaseoli Beet Yellows F. oxysporum f. sp.betae Broccoli, Cauliflower, Cabbage,Collard Yellows F. oxysporum f. sp. conglutinans Celery Yellows F. oxysporum f. sp. apii Muskmelon Wilt F. oxysporum f. sp. melonis Pea Wilt F. oxysporum f. sp. pisi (race 1) Pea Near Wilt F. oxysporum f. sp. pisi (race 2) Radish Yellows F. oxysporum f. sp. raphani Spinach Wilt F. oxysporum f. sp. spinaciae Tomato Wilt F. oxysporum f. sp. lycopersici Watermelon Wilt F. oxysporum f. sp. niveum

SUMMARY The purpose of nutrition and disease control is to increase crop production efficiency. Plant fertility is an important part of an IPM program. Many cultural practices which reduce disease work by influencing nutrient uptake. Nutrition is most effective with tolerant varieties. Nutrient stressed plants may be more susceptible to disease.

SUMMARY (Continued) Any single element may reduce severity of one disease, but increase another. No nutrient controls all diseases - each disease and environment should be considered within the production system. The form of a nutrient may be as important as the rate. It is important to maintain a balanced nutrition.