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25 Cards in this Set
- Front
- Back
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Its impossible to edadicate plant disease.
so we manage this problem try to keep it to an ... |
acceptable level
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contolling plant disease involves preventing disease incidence or severity. Remember the disease triangle.
Control usually conerns what? |
control involves plant populations rather than individual plants
only are we intrested in just one plant unless its an old ornamental tree. so we don't view this as an individual plant issue like a human. its the entire crop or landscape. But a single plant can serve as a inoculum for the whole planting |
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Plant disease involves app of one or more of the following:
avoidance exclusion eradication protection disease resistance therapy so what? |
avoidance = planting at times pathogens are rare
exclusion = preventing est of pathogens in path free area eradication = reducing destroying pathogen at its source, protection = prevent infection by est a barrier b/t host and pathogen ie chemicals waxes screens filters disease resistance = plant resistance plants or altering gorwth of plants to make them tolerant therapy = reducing severity of infected plant. w/ chemicals |
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Cultural & Plant Mang practices
some planting sites are harder than others. dew and long humudity next to waterways! or b/t hills! so you get leaf flower stem disease there. So sites have histories of water sogged soil or root rot. so? |
so don't plant susceptible plant species in this enviroment unless your prepared to use control strategies
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proper planting time/methods
wet & cool soils favor seed rot / seedling disease. So do what? |
delay planting until soil moisture / temps are good! Also moisture/temps can vary w/ particular plants/pathogen species. Also improper planting depth can lead to poor stands due to seedling diseases.
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proper plant nutrition
plant heath begins w/ proper nutrition. ***************************** many plant disese are ... |
less severe when plant nutrition are properly balanced
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plant & crop rotation / plant sequence
big problems happen in those fields that don't rotate the crops. disease to landscapes also that don't rotate. does plant rotation help control plant pathogens? but what if you plant 3 different species but all 3 species are susceptible to same pathogen, what? |
severe disease can happen to any of them at any time.
EX. don't plant one bean crop after another, or certain annuals after another! Rotating is expecially valuable controlling root diseases that cannot be controlled any other way ****************************** |
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landscape & field sanitation
lots of fungus & bacteria which infect above ground plnat parts or root disease can what? |
survive only in plant debris.
so removing this stuff or deeply incorporating crop residues back in will give partial control. So leaving plant debis remains on the soil surface, helps present further disease. **************************** |
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control plants that are inoculum reservoirs
neaby weeds or volunteer crop plants and other alternate hosts act as inoculum reservoirs. what do we now do? |
remove unwanted vegitation
eliminate alternate hosts eradicate alternate hosts EX getting rid of barberry will eradicate stem rust of wheat |
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clean harvest & tillage equipment
tires can move a pathogen around so ... |
clean the equipment
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proper harvesting methods
improper harvesting methods bruise damage tubers fruit seed and leave huge amts of foreign matter what? |
leave allot of foreign matter mixed in w/ harvest. this leads to storage and affects quality.
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proper storage of harvested plant parts
subjects harvast to... |
several groups of microorganisms. chemical treatments control this in storage for some of this
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Reisitant or Tolerant Varieties
planting disease resistant varieties is what? |
most effective & eco means of controlling plant disease if its there to buy in the first place.
plant varieties have varying degrees of resistance. there are highly resistant, moderately resistant, and mod susceptible to describe a variety to resist infection |
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the term Torerant = what?
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a plant variety that can be infected & still suffer little reduction in yeild or quality
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Use of Disease - Free Seed & Progagation
Planting certified seed is a great way to control plant disease. so it many be necessary to plant seed or plant parts to ... |
eradicate certain pathogens.
Remember! it is easier to prevent the intro of a pest than to control it once it is established. so buy certified disease free seed is the important factor in disease control |
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control of vectors
vector management is only way to control ... |
certain pathogens like viruses and MLOs. from insects, mites, etc.
disease dissemination doesn't occur if the vector can be managed. EX controlling curly top virus is curbing or excluding leafhopper vector |
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Chemical Control
chemicals are used less for disese control than for insect and weed control. BUT some chems can be used for diease mang. & ... |
maybe only way or practicle method avaliable
chems really blast fugus but less effective against bacteria and MLOs. ***************************** not avaliable against viruses ***************************** |
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you will need chemicals to control disease if:
adapted plant varieties are not avaliable cultural controls are sketchy crop rotation isn't possible crop value per acre or landscape $$$$ crop / landscape quality is way down by the disease sudden outburst of disease YOU can decide using chemicals first consider... |
id the disease or pathogens
plant parts that need protection products are registered / avaliable chemical mode of activity against target pathogens/ avaliable formulations method of application number / freq of apps potential for phytotoxity etc weather cultural mang practices safety of product to applicators & enviro |
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FUNGICIDES
its harder to control fungal disease w/ chemicals that to control insects & weeds. ****************************** fungal pathogens live close association w/ its host, making it what? |
extremely hard to control w/o killing the host
most fungicides prevent germination of spores or protect plant plant from fungal penetration. you have to keep putting it on all season long. do it in uniform apps really make sure you get everything BECAUSE inoculum on an untreated place spread disease. get it when it is just starting, don't wait here. |
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Protectant MUST cover ALL
plant tissue to protect the plant old tissue new tissue what is another type of fungicide kills or stops spread of pathogens after its become established? |
ERADICANS
use eradicans once fungus is established use eradications when its too late to use protectants or too expensive. most eradicants are systemic materials absorbed/translocated thru plant. some systemic fungicides are used as protectants. |
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INORGANIC FUNGICIDES
successful for disease for nearly 100 years. sulfur and Bordeaux mix examples of inorganic fungicides. generally broad spectrum, they are low toxic to humans & animals. but what? |
considered to cause lots of damage to plants.
this is why they were replaced by synthetic organic fungicides |
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Synthetic Organic Fungicides
been around 100 years. highly selective, have residual properties, less toxic to crops & less harmful to enviro. what are some ex here? |
ziram
benomyl metalazyl sterol inhibitors |
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BACTERICIDES
chemicals for control largely unsuccessful. But some compounds used for control of fungal disease work. like what? |
copper compounds
Bordeaux mix some control of bacterial leaf spots/ blights |
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New discipline here is
ANTIBIOTICS works for humans / animals so why not plants? antibiotics are chemical compounds produced by bacteria and fungi w/ are ? |
toxic to other organisms!
some of this is in use |
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NEMATICIDES
chemicals used to control nematodes used as a ... |
preventitive measure.
by the time nematode damage is discovered, its too late so doing anything about it is too late. So Nematicides are preventives. Based on preplant apps, usually 10 days to 2 weeks b/f planting ***************************** So chemical treatment of soil is most used practice to control nematodes. soil fumigants nonfumgant nematicides in granular & liquid formulas. |
