31. Plant Disease And Fungicides

Front 1

what is the importance of fungi in causing infectious plant diseases?

Back 1

75% of infectious plant due to fungi, may have 10-50 different fungi on same plant

Front 2

how are fungi classified? what are these classifications?

Back 2

classified to lifestyle
airborn infections, seedborne infection, and soilborne infection

Front 3

why are fungi difficult to control?

Back 3

selectivity between fungi and plant hard to achieve because both plant like and live close to each other

rapid reproduction

regeneration of mycelium

develop resistant strain quickly

Front 4

what is most challenging fungi to control

Back 4

hardest fungi to control are those below ground

Front 5

what elements were used in early fungal control?

Back 5

slfur, copper, mercury
work by retarinding growth, but mercury is toxic so not allowed to be used

Front 6

how do fungicides kill or stop development of fungi? (what is the purpose)

Back 6

purpose is to kill or halt development of fungi

most prevent spore germination or kill spore immediately following germination

inhibit subsequent fungal penetration of plant tissues and growth after infectious stage has developed

Front 7

which types of fungicides readily enter fungi?

Back 7

non cationic fungicides

Front 8

what serves as main barrier of penetration of fungi?

Back 8

lipoprotein menbrane (plasmalemma) within cel wall

Front 9

are spores easy to penetrate?

Back 9

no, but become susceptible at time of emergence of germ tube

Front 10

how are fungicides transported through the cell or syncytium?

Back 10

protoplasmic streaming

Front 11

what are different types of fungicides? how do they used?

Back 11

chemotherpeutants - apply aat plant stages vulnerable to inoculation (before symptom occur)

protectants - repeated treatments due to plant growth dilution with full coverage, apply in advance of pathogens to prevent disease

eradicants- apply directly to pathogen during overwhelming stage, long before disease and symptoms

seed treatments- for grain crops

systemics - seed and soil treatments for slow absorption and prolonged disease control

Front 12

advantage to using systemic fungicides?

Back 12

eradicant properties to stop the progression of existing nfetion- attack internal mycelium and penetrating haustoria

therapeutic- cure plant disease

reduce level of environmental contamination by frquent broadcast application of nonsystemic fungicides

Front 13

disadvantage to using systemic fungicides?

Back 13

resistance and cross resistance serious problems due to specificity, single gene mutation gives resistance

very persistent even when use halted

Front 14

what are fungicides class by mode of action?

Back 14

p.245