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Diagnosing Plant Disorders Introduction to Plant Science J.G. Mexal
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“a condition of the plant body or of one of its parts that impairs normal functioning.” Webster’s Dictionary Definition of ‘Disease’
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Pest Outbreak Triangle/ PNW,2000
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Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human
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Diagnosing Plant Disorders Steps: Make careful observations Use good judgment Understand the plant Understand the causes of plant problems Ask questions Know the plant’s environment
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Diagnosing P lant Disorders Diagnostic Procedures: Examine leaves Examine trunk and branches Examine roots
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Diagnosing P lant Disorders Resources: SWAT Lab CES county agent CES specialists: pathologists, entomologists
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Diagnosing P lant Disorders Non-infectious or abiotic disorders: Mechanical injury –soil compaction –change of grade –DPD –animals (other than human) moles & voles, sapsuckers, dogs, tipmoth, gall insects, spider mites, eriophyid mites, borers, aphids, bark beetles ash, chilopsis, creosote, pine
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Diagnosing P lant Disorders Non-infectious or abiotic disorders: Mechanical injury Chemical –herbicides –salt –soil sterilants Thermal Nutrient
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Diagnosing P lant Disorders Non-infectious or abiotic disorders: Mechanical injury Chemical Thermal –ice –lo T (spring, fall, winter) –hi T (water, wind) Nutrient
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Diagnosing P lant Disorders Non-infectious or abiotic disorders: Mechanical injury Chemical Thermal Nutrient –N, Fe, micros –O 2, H 2 O
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Diagnosing P lant Disorders Infectious or biotic disorders: Leaf diseases Cankers Root rots Nematodes Mistletoe
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Diagnosing P lant Disorders Common diseases of the SW: Crown gall (locust, plum, AZ cypress) Wetwood (willow, mulberry, cottonwood) Cotton Root Rot (acacia, vitex, golden raintree) Mistletoe (ash, cottonwood) Verticillium wilt (chitalpa, golden raintree)
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Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human
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What’s Killing Your Trees Factors Affecting Acclimation-Tissue Tolerant Pinus pinea –Shoots = - 40 o C –Roots = -10 o C Intolerant Eucalyptus camaldulensis –Shoots = -10 o C –Roots = - 3 o C
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What’s Killing Your Trees Factors Affecting Acclimation-Size Spring Buds = -3 o Cambium = -4 o Roots = -4 o Seedling = -3 o Germinant = -2 o Winter Buds = -25 o Cambium = -50 o Roots = -10 o Seedling = -30 o
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What’s Killing Your Trees Cold - Hardiness of Apple Blooms Approximate Calendar Date LT 50 ( o C)
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What’s Killing Your Trees Freeze Injury E. Shannon
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What’s Killing Your Trees SW Injury Ash Pine Willow E. Shannon Pecan
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What’s Killing Your Trees SW Injury Protection E. Shannon
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What’s Killing Your Trees Water Stress Increases Winter Injury - Leucaena leucocephala Distance from runoff water (m) Dieback (% of maximum)
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What’s Killing Your Trees Fertilize Your Trees
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What’s Killing Your Trees J. Mexal
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Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human
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What’s Killing Your Plant Cliff Notes® Water your darn trees!!!
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Piñon is moving up the hill/ after Ryerson 2006 Elevation (ft) Piñon Mortality (%)Stocking (% Piñon ) ■, ♦ = Northern □, ◊ = Southwest (wh) □, ◊ = Southcentral (gr)
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J. Mexal What’s Killing Your Trees What is wrong with this picture?
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Dr. Death’s Tree Care Guide Las Cruces’ Tree Water Requirements
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Dr. Death’s Tree Care Guide Pecan Irrigation Requirements Water (in/mo)
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Dr. Death’s Tree Care Guide Afghan Pine Irrigation Requirements Water (inmo)
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Dr. Death’s Tree Care Guide Las Cruces’ Tree Water Requirements Water Use (in/yr) After Sammis & Jerigan 1992
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Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human
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What’s Killing Your Trees Chlorosis Iron Freeze? Herbicide E. Shannon
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What’s Killing Your Trees Chlorosis to the point of Albinism! Herbicide damage J. Mexal
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E. Shannon What’s Killing Your Trees Zinc Deficiency
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Abaxial Adaxial What’s Killing Your Trees Phosphorus Deficiency? Or Fall? Chinese Pistache
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Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human
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What’s Killing Your Trees Cytospora on Poplar E. Shannon
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What’s Killing Your Trees Powdery Mildew Pecan Apple Cherry Lilac w/ fruiting bodies E. Shannon
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What’s Killing Your Trees Anthracnose on Sycamore
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What’s Killing Your Trees Fruiting Structure (conk) of Heart Rot
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aka Texas Root Rot Attacks: pine, pecan, fruit trees What’s Killing Your Trees Cotton Root Rot
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