Diagnosing Plant Disorders Introduction to Plant Science J.G. Mexal

“a condition of the plant body or of one of its parts that impairs normal functioning.” Webster’s Dictionary Definition of ‘Disease’

Pest Outbreak Triangle/ PNW,2000

Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human

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

Diagnosing P lant Disorders Diagnostic Procedures: Examine leaves Examine trunk and branches Examine roots

Diagnosing P lant Disorders Resources: SWAT Lab CES county agent CES specialists: pathologists, entomologists

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

Diagnosing P lant Disorders Non-infectious or abiotic disorders: Mechanical injury Chemical –herbicides –salt –soil sterilants Thermal Nutrient

Diagnosing P lant Disorders Non-infectious or abiotic disorders: Mechanical injury Chemical Thermal –ice –lo T (spring, fall, winter) –hi T (water, wind) Nutrient

Diagnosing P lant Disorders Non-infectious or abiotic disorders: Mechanical injury Chemical Thermal Nutrient –N, Fe, micros –O 2, H 2 O

Diagnosing P lant Disorders Infectious or biotic disorders: Leaf diseases Cankers Root rots Nematodes Mistletoe

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)

Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human

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

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

What’s Killing Your Trees Cold - Hardiness of Apple Blooms Approximate Calendar Date LT 50 ( o C)

What’s Killing Your Trees Freeze Injury E. Shannon

What’s Killing Your Trees SW Injury Ash Pine Willow E. Shannon Pecan

What’s Killing Your Trees SW Injury Protection E. Shannon

What’s Killing Your Trees Water Stress Increases Winter Injury - Leucaena leucocephala Distance from runoff water (m) Dieback (% of maximum)

What’s Killing Your Trees Fertilize Your Trees

What’s Killing Your Trees J. Mexal

Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human

What’s Killing Your Plant Cliff Notes® Water your darn trees!!!

Piñon is moving up the hill/ after Ryerson 2006 Elevation (ft) Piñon Mortality (%)Stocking (% Piñon ) ■, ♦ = Northern □, ◊ = Southwest (wh) □, ◊ = Southcentral (gr)

J. Mexal What’s Killing Your Trees What is wrong with this picture?

Dr. Death’s Tree Care Guide Las Cruces’ Tree Water Requirements

Dr. Death’s Tree Care Guide Pecan Irrigation Requirements Water (in/mo)

Dr. Death’s Tree Care Guide Afghan Pine Irrigation Requirements Water (inmo)

Dr. Death’s Tree Care Guide Las Cruces’ Tree Water Requirements Water Use (in/yr) After Sammis & Jerigan 1992

Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human

What’s Killing Your Trees Chlorosis Iron Freeze? Herbicide E. Shannon

What’s Killing Your Trees Chlorosis to the point of Albinism! Herbicide damage J. Mexal

E. Shannon What’s Killing Your Trees Zinc Deficiency

Abaxial Adaxial What’s Killing Your Trees Phosphorus Deficiency? Or Fall? Chinese Pistache

Types of ‘Disease’ Abiotic - Physcial Factors –Temperature –Moisture –Nutrients Biotic - Biological –Insect –Disease (Fungi, Bacteria, Virus) –DPD- human

What’s Killing Your Trees Cytospora on Poplar E. Shannon

What’s Killing Your Trees Powdery Mildew Pecan Apple Cherry Lilac w/ fruiting bodies E. Shannon

What’s Killing Your Trees Anthracnose on Sycamore

What’s Killing Your Trees Fruiting Structure (conk) of Heart Rot

aka Texas Root Rot Attacks: pine, pecan, fruit trees What’s Killing Your Trees Cotton Root Rot