Certified Arborist. Diagnosis and Plant Disorders. What is a healthy plant?

Transcription

1 Certified Arborist Diagnosis and Plant Disorders What is a healthy plant? Vitality Ability to deal with stress Vigor Genetic ability to deal with stress 1

2 Many things combine to cause decline! Plant Health Care Matches plants to the environment 2

3 Plant health problems Biotic (living) insects, mites, mammals, birds, fungi, bacteria, viruses, nematodes infectious Abiotic (non living) temperature, moisture, mechanical, injury, chemical, mineral deficiency Non infectious Step 1 Diagnosis 3

4 Step 2 Appropriate recommendation Ask questions How long has problem been going on? What were early symptoms Has there been construction excavation chemical treatments 4

5 Be aware that the homeowner often thinks- My tree died overnight! Diagnosis is Systematic Information gathering Observation Logical analysis SOMETIMES ITS EASIER TO ELIMINATE POSSIBILITIES 5

6 Step 1 Accurately identify the plant Can limit causes of problem Many biotic factors are host specific Certain species are sensitive to certain abiotic disorders Important to know whats normal for that species Step 2 Look for abnormal pattern Biotic often non uniform Abiotic uniform pattern 6

7 Step 3 Carefully examine site Grade changes Herbicides Gas leaks Shade change Overcrowding New structures Chemicals Step 4 Examine Foliage Note color, size and thickness Crown root and trunk damage Distorted insects, 2,4 D, viral Early fall color roots 7

8 Step 5 Check the trunk and branches Wounds Holes Lightning Water sprouts Step 6 Examine root collar Color Rot ph Moisture 8

9 70-90% of all plant problems are cultural or environmental! Most problems are complex Rarely a single cause IE. SOOTY MOLD Sooty Mold Culprits 9

10 Results Symptoms vs signs 10

11 Signs vs. Symptoms Signs Direct indications of a particular problem Fruiting bodies Insect frass Emergence holes Bark injury Symptoms Effects of a disease or other disorder Leaf wilting Leaf spots Leaf scorch Dieback Leaf Spot Symptoms Dead tissue on foliage Varied appearance Small areas 11

12 Leaf Blotch Symptoms Dead areas on foliage Irregular Larger than spot Scorch Symptoms Browning around margins and between veins 12

13 Blight Dieback of leaves and twigs Especially New Growth Wilt Drooping Often lack of water Soil borne fungi 13

14 Cankers Localized dead stem tissue Shrunken and discolored Gummosis Sap (gum) from wounds 14

15 Rust Orange pustlues on leaves, galls etc. Gall Swollen plant tissue Irregular plant growth 15

16 Chlorosis Yellowing due to lack of chlorophyll Necrosis Death of tissue 16

17 Dieback Dead portions of tree Powdery mildew White to grayish fungal growth on leaves Looks like powder 17

18 Vascular discoloration Darkening of wood s vascular elements Witch s Broom Abnormal development of multiple secondary shoots 18

19 Acute is sudden Tree Stress Acute vs Chronic Causes: freezing, pesticide, etc. Chronic is long term Causes: site, environment, poor site choice, water, temperature, soil, mechanical Can be treated by changing the conditions Abiotic Disorders 19

20 Soil and Site Problems Don t fall into trap of looking at only trunk and banches ROOTS! Remember upper can be due to lower Physical and Mechanical Injury 20

21 Competition Sunlight Soil nutrients Water Growing Space Allelopathy 21

22 Pollution Damage (air, soil, water) Chemical Injury Herbicides mainly Curl and cupping Wilt Parallel veination Yellowing Defoliate Death, HOWEVER, trees rarely die Nonselective hrbs/soil sterilants casue gretest damage 22

23 Minimize damage Separate herbicide sprayer Cool, calm days Low pressure Target spray Read label Beware of the root zone Biotic Disorders Living Insects and cousins, Nematodes, Diseases 23

24 General vs Specific Pests LIFE CYCLE is IMPORTANT Know ID Damaging stage Plant tolerance Egg-laying Cicada 24

25 Feeding Damage THINK MOUTHPARTS Chewing Mouthparts Put holes in things 25

26 Caterpillars eat leaves Gypsy moth Eastern Tent Caterpillar Cankerworms Black vine weevils eats leaf margins Also cresent shaped notches 26

27 Beetles Japanese Beetle Elm Leaf Beetle Leafminers 27

28 Borers Eat in phloem, cambium or xylem Notice crown thinning first Piercing sucking Mouthparts 28

29 Aphids Scales 29

30 Leafhoppers Adelgids Actually aphids with wooly hair 30

31 True bugs Mites Spider Eriophyid (galls) 31

32 Insects as vectors Dutch Elm Disease (DED) Fireblight Viruses Nematodes Microscopic roundworms Most are not parasitic Vectors Swelling, deformity or blockage Enter thru roots, stomata, wounds, etc. 32

33 Four requiremetns for disease Diseases

34 Managing Tree Health Prevention Treatment Learning to live with it Getting Help ASK-UGA1 34