Term
|
Definition
|
|
Term
|
Definition
|
|
Term
Crown Gall
Bacterial tumor |
|
Definition
| Agrobacterium tumefaciens |
|
|
Term
| Scorch Disease of Orange or Landscape hardwood |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
Bacterial Canker
(Tomato Canker) |
|
Definition
| Corynebacterium michiganense |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
Black Scurf on Potato
Land of Tubers |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| Colletotrichium (Glomerella cingulata) |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Southern Blight of Herbaceous Plants |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Powdery Mildew of Cereals and Grasses |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
Witchweed
(Parasitic Plant) |
|
Definition
|
|
Term
|
Definition
| Collectotrichum gaminicola |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| What is Damping off? What causes it? |
|
Definition
Infection of the seed or seedling caused by pythium, fusarium, or rhizoctonia.
Mostly caused by fungi. |
|
|
Term
| How can one manage damping off? |
|
Definition
The best strategy is avoidance by clean seed and soil. Pythium is attracted thru chemotactics due to the nutrient rich seed.
Do not use chemicals, just remove plant and be sure to plant new seeds in optimal plant growth conditions. |
|
|
Term
| What are necrotic spots (plus blight, blotch, needlecast, scab)? What are the optimal growth conditions? |
|
Definition
Dead tissue in leaves caused by fungi (round) or bacteria and nematodes (angular).
They like warm and humid environments, and foliar nematodes need water to move. |
|
|
Term
| This pathogen has sticky conidia that are spread by mowers to wounded plants. It is a concern to golf courses. |
|
Definition
| Anthracnose of turfgrass. It's a concern to golf courses because they put stress on the grass. |
|
|
Term
| What can plants do to prevent spread of necrosis? |
|
Definition
| Plants may shed infected parts. For example, necrosis of needles results in the eventual casting away of needles. |
|
|
Term
| Can the same pathogen have different effects depending on which part of the plant it infects? |
|
Definition
| Yes, Guignardia bidwellii on grapes causes severe black rot of grapes. However, on the leaves it causes minor necrosis. |
|
|
Term
| Anthracnose: what are the structures and what are the symptoms? |
|
Definition
| They have acervulus (black setae) and they caused scabby depressions in fruit. |
|
|
Term
|
Definition
Abnormal color or form
-mosaic
-mottle
-ring spots
-rugosity
-vein banding
-flower break |
|
|
Term
| What are some important viral diseases in Hawaii? |
|
Definition
| Papaya ring spot and banana bunchy top virus |
|
|
Term
| What are some diagnostic signs of powdery mildew? |
|
Definition
| white powder on top of leaf. They are host specific. they are able to germinate in high humidity instead of free water. |
|
|
Term
|
Definition
| the overwintering fruiting bodies of powdery mildew. Ascospores are released from asci. |
|
|
Term
| What are symptoms of downy mildew? |
|
Definition
| powdery substance is on the bottom of leaves and they are caused by oomycetes. It is usually host specific. |
|
|
Term
| What are the two types of rust? |
|
Definition
| Heteroecious and Autoecious |
|
|
Term
| define macrocyclic, demicyclic, and microcyclic |
|
Definition
Macrocyclic has all 5 stages
demicyclic has all but uredenial spores (repeating), it only produces primary innoculum.
microcyclic has only teliospores and basidiospores. |
|
|
Term
| How can you manage heteroecious demicyclic rust? |
|
Definition
Remove one of the hosts.
Apple = juniper
White pines = gooseberry
|
|
|
Term
| What is the Puccinia pathway, and why was the program to control it successful? |
|
Definition
| the travel of puccinia from the south towards the north. it was successful because the removal of barberry reduces genetic recombination. The main host was wheat. |
|
|
Term
| What are other ways to manage rusts? |
|
Definition
genetic resistance, minimizing leaf wetness, removal of infested debris, and fungicides.
(they like high nitrogen, so maybe the proper fertilization) |
|
|
Term
| How are vascular wilts spread? |
|
Definition
| via insects and soil transmission |
|
|
Term
| Name some important vascular wilt pathogens (ascomycetes and bacteria) |
|
Definition
| stewart's wilt, miko disease, verticillium wilt, fusarium wilt, duch elm disease, and oak wilt. |
|
|
Term
| How is Dutch Elm Disease spread? |
|
Definition
| European elm bark beetle. it killed all the elm that lines the streets. |
|
|
Term
| What are the symptoms of xylem-limited fastidious bacteria and how is it managed? |
|
Definition
| It is spread by insects ONLY. Management is difficult and it is best to remove infected plants to reduce spread. An example is Pierce's disease of grape vines. |
|
|
Term
| What are symptoms of phloem-limited fastidous bacteria and viruses? How is it managed? |
|
Definition
| symptoms include stunting, yellowing, and witch's broom. antibiotics can manage bacteria, and insecticides and prevent spread of viruses. |
|
|
Term
| What causes cankers and how is it transmitted? |
|
Definition
| Cankers are caused by fungi or bacteria and is transmitted by sap. |
|
|
Term
| What is an example of canker and what is its significance? |
|
Definition
| Chestnut blight (cryphonectria parasitica). It used to be a dominat tree in the appalacian mountain, but after the pathogen was introduced from Asia, they all died. It was a source of timber, nuts, and tannins. |
|
|
Term
|
Definition
| galls are caused by bacteria, fungi, insects, nematodes, or viruses. |
|
|
Term
| What are examples of galls? |
|
Definition
| corn smut, black knot, root knot nematode, clubroot brassicas, crown gall (agrobacterium tumefaciens). |
|
|
Term
| What is hypertrophy and hyperplasia |
|
Definition
| Hypertrophy is the increase in size. Hyperplasia is the increase in number. |
|
|
Term
| What are root rots? How is it managed? |
|
Definition
Roots are damaged from the environment (drought, freezing, poor drainage, nematodes), and then saphrophytes infect.
The best way to manage it is thru chemical treatment or heating before a new crop. |
|
|
Term
|
Definition
| Nope, not really, and they spread through root contact. No chemical treatments. |
|
|
Term
| What are post harvest diseases? |
|
Definition
| the produce can have latent pathogens prior to harvesting. they can be controlled by dipping in chemicals, keeping the area clean and dry, and stored in cool conditions. The fruit should be kept wound free. The fruits become more susceptible upon ripening. |
|
|
