Mineral Nutrition of Fruit & Nut Trees R. Scott Johnson Extension Pomologist UC Kearney Ag Center Fruit & Nut Tree Nutrition 1. Basic Principles 2. Sampling for Nutrients 3. Environmental Issues 4. BMPs 5. Individual Nutrients Johnson Nutrition 1
Essential Nutrients Photosynthesis Carbon Oxygen Hydrogen Macro Nutrients Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur Micro Nutrients Zinc Iron Boron Manganese Copper Chlorine Nickel Molybdenum Average concentrations of mineral nutrients in plant shoot dry matter. Element ppm Relative number of atoms Molybdenum 0.1 1 Nickel ~0.1 1 Copper 6 100 Zinc 20 300 Manganese 50 1 000 Iron 100 2 000 Boron 20 2 000 Chlorine 100 3 000 Sulfur 0.1 30 000 Phosphorus 0.2 60 000 Magnesium 0.2 80 000 Calcium 0.5 125 000 Potassium 1.0 250 000 Nitrogen 1.5 1 000 000 Johnson Nutrition 2
Nutrient Mobility Phloem mobility, Marschner 1997 Mobile Sodium Potassium Phosphorus Chlorine Sulfur Nitrogen Magnesium Partially Mobile Zinc Copper Boron Iron Molybdenum Immobile Calcium Manganese Boron Mobility Mobile Apple Peach Plum Cherry Olive Immobile Walnut Pistachio Most other plants Johnson Nutrition 3
Carbon Boron Hydrogen Oxygen a b Role of Zinc in Plants Has a role in 80 processes Auxin synthesis Cell division Protein synthesis Zinc fingers DNA replication & transcription Not involved in photosynthesis Schematic Diagram of the Causes of Zinc Deficiency in Crops Low total zinc content in soil (e.g., sandy soils) High soil ph (e.g., calcareous soils, heavily limed soils) Zinc inefficient crop varieties High soil organic matter content (e.g., histosols) ZINC DEFICIENT CROP reduced yield impaired quality High phosphate applications High salt concentrations (salinity) Waterlogging / flooding of soil (e.g., rice paddy) Johnson Nutrition 4
Fruit & Nut Tree Nutrition 1. Basic Principles 2. Sampling for Nutrients 3. Environmental Issues 4. BMPs 5. Individual Nutrients ph Effects on Nutrient Availability Johnson Nutrition 5
Nutrient Elements in Stone Fruit Level in leaves PEACHES AND NECTARINES Deficient below Optimum range Toxic over Deficient below PLUMS Optimum range Toxic over N P K Ca Mg Cl S Fe Mn Zn B Cu Mo 2.3 1.0 0.25 60 20 15 18 2.6 3.0 0.1 0.3 Over 1.2 Over 1.0 Over 0.25 Over 60 Over 20 Over 20 20 80 Over 4 0.3 100 1.0 0.25 p p m 20 18 25 4 2.3 2.8 0.1 0.3 Over 1.1 Over 1.0 Over 0.25 Over 20 Over 18 30 60 Over 4 0.3 80 Johnson Nutrition 6
Nutrient Elements in Stone Fruit Level in leaves PEACHES AND NECTARINES Deficient below Optimum range Toxic over Deficient below PLUMS Optimum range Toxic over N P K Ca Mg Cl S Fe Mn Zn B Cu Mo 2.3 1.0 0.25 60 20 15 18 2.6 3.0 0.1 0.3 Over 1.2 Over 1.0 Over 0.25 Over 60 Over 20 Over 20 20 80 Over 4 0.3 100 1.0 0.25 p p m 20 18 25 4 2.3 2.8 0.1 0.3 Over 1.1 Over 1.0 Over 0.25 Over 20 Over 18 30 60 Over 4 0.3 80 Johnson Nutrition 7
Nutrient Elements in Stone Fruit Level in leaves PEACHES AND NECTARINES Deficient below Optimum range Toxic over Deficient below PLUMS Optimum range Toxic over N P K Ca Mg Cl S Fe Mn Zn B Cu Mo 2.3 1.0 0.25 60 20 15 18 2.6 3.0 0.1 0.3 Over 1.2 Over 1.0 Over 0.25 Over 60 Over 20 Over 20 20 80 Over 4 0.3 100 1.0 0.25 p p m 20 18 25 4 2.3 2.8 0.1 0.3 Over 1.1 Over 1.0 Over 0.25 Over 20 Over 18 30 60 Over 4 0.3 80 Johnson Nutrition 8
Fruit & Nut Tree Nutrition 1. Basic Principles 2. Sampling for Nutrients 3. Environmental Issues 4. BMPs 5. Individual Nutrients Orchard Nutrition Main environmental issue: Nitrate N escaping into water systems & Gaseous N escaping into the atmosphere Johnson Nutrition 9
Johnson Nutrition 10
Nitrogen Fertilization in the San Joaquin Valley (#N/ac or KgN/ha) Crop Almonds Pistachios Peaches Grapes 2030 yrs ago 250300+ 250 150 50100 Now 200250 150175 075 3060 Fruit & Nut Tree Nutrition 1. Basic Principles 2. Sampling for Nutrients 3. Environmental Issues 4. BMPs 5. Individual Nutrients Nitrogen (N) Found in amino acids, proteins, enzymes, nucleic acids (DNA), chlorophyll etc. N can easily be lost from the orchard by leaching of nitrate and from denitrification or volatilization 50 recycled in senescing leaves Johnson Nutrition 11
Nitrogen Deficiency Johnson Nutrition 12
Apply 25 to 50 lbs/acre Apply before leaf senescence (Oct) OK to apply with zinc sulfate Doesn t need to be low biuret Foliar Urea Johnson Nutrition 13
Nitrogen Management Low N High N Johnson Nutrition 14
Occurrence of Nutrient Deficiencies in California Common Nitrogen Zinc Iron Occasional Potassium Magnesium Manganese Rare Phosphorus Boron Copper Unknown Calcium Sulfur Molybdenum Zinc Deficiency Little Leaf Disorder Johnson Nutrition 15
Zinc Deficiency in Plums Zinc Deficiency in Plums February 22, 2005 Zn Deficient Zn Sufficient Johnson Nutrition 16
Peach Rootstocks and Zn Uptake December 2006 Shoot Zn 100 a Shoot Zn (ppm) 80 60 40 b 20 c c 0 Nemaguard Controller 5 Controller 9 Hiawatha Comparing Zinc Formulations Ranking Formulation Anion Size Solubility (g/100 H 2 O) Phytotoxicity Most Effective Zinc Chloride 35 432 High (58*) Almost As Good Next Best Less Effective Least Effective Zinc Nitrate 62 324 High (54) Zinc Nitrate Mix 62 & 96 324 High (59) Zinc Sulfate 96 50 Moderate (12) Zinc Carbohydrate 96 &? High Moderate Zinc Polyamine 96 & 75204 High Moderate Zinc Glycine 96 & 75 Moderate (15) Zinc EDTA 292 High Low Zinc Leonardite 1000+ High Low Zinc Oxysulfate 16 & 96 1.3 None Zinc Phosphite 79? Low (17) Zinc Oxide 16 Insoluble None Suspension Johnson Nutrition 17
Orchard Survey Zinc Number of Orchards 20 18 16 14 12 10 8 6 4 2 0 8 10 12 14 16 18 20 22 24 26 28 30 More July Leaf Zn (ppm) Zinc in Dormant Shoots (ppm) Deficient Sufficient High 6.4 13.7 26.5 8.1 21.6 50.0 10.1 35.6 74.5 Johnson Nutrition 18
Orchard Survey Zinc Number of Orchards 9 8 7 6 5 4 3 2 1 0 5 10 15 20 25 30 35 40 45 50 January Shoot Zn (ppm) Zinc Fertilization Apply if symptoms appear or leaf Zn < 10 to 12 ppm or Sept shoot Zn < 20 ppm If needed in mature trees spray 4 to 8 lbs/acre of zinc sulfate (36 Zn) in early fall can be applied with urea Calcium in Fruit Trees Exists as a Ca ++ cation in the soil Very plentiful in most soils Component of cell walls Many cell breakdown disorders caused by Ca deficiency bitter pit in apples Very immobile in plants high levels in leaves but low levels in fruit Johnson Nutrition 19
Foliar Calcium Formulations Flavorcrest Peach Fruit Calcium at Harvest Fruit Ca (ppm) 500 400 300 200 100 0 a a b Nemaguard K11950 P30135 Rootstock Johnson Nutrition 20
Calcium (Ca) Ca deficiency will not occur until leaf levels are 1.0 Ca or lower in mid summer leaves Deficiency not found in the field Foliar sprays show no benefit Iron Chlorosis Johnson Nutrition 21
Iron Chlorosis Usually caused by high ph soils Major problem in some countries Iron deficiency can: Reduce fruit size Reduce yield Add soil sulfur or sulfuric acid to portion of root zone to decrease ph Rootstocks make a big difference Johnson Nutrition 22
Boron Boron in Fruit Trees Micronutrient only need 30 ppm Sometimes deficient in fruit trees Plays a major role in fruit set Immobile in most plants Mobile in some fruit trees those that use sorbitol as a transport sugar Boron (B) No leaf symptoms or fruit disorders in sand tanks Differences in fruit size and fruit set due to B Easy to correct using solubor Timing more critical in B immobile plants Johnson Nutrition 23
Orchard Survey Boron Number of Orchards 18 16 14 12 10 8 6 4 2 0 15 20 25 30 35 40 45 50 55 60 65 70 75 July Leaf B (ppm) Potassium (K) Very mobile in plants, important in stomatal guard cell opening, cell turgor, translocation of sugars, activation of enzymes, disease resistance etc. Potassium Johnson Nutrition 24
Orchard Survey Potassium Number of Orchards 14 12 10 8 6 4 2 0 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 July Leaf K () Johnson Nutrition 25
Potassium in Fruit Trees Very mobile in plants Occasionally deficient in the field Easy to correct with potassium sulfate Extreme Phosphorus Deficiency Peach Skin Cracking Johnson Nutrition 26
Nectarine Skin Cracking Johnson Nutrition 27
Orchard Survey Phosphorus Number of Orchards 16 14 12 10 8 6 4 2 0 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 July Leaf P () Phosphorus (P) Found in nucleic acids (DNA), energy molecules (ATP) and membranes P is not as easily lost from the orchard as N 50 recycled in senescing leaves Manganese Deficiency Johnson Nutrition 28
Orchard Survey Manganese Number of Orchards 16 14 12 10 8 6 4 2 0 20 30 40 50 60 70 80 90 100 More July Leaf Mn (ppm) Johnson Nutrition 29