PLANT DISEASES: CAUSES AND DIAGNOSIS

Question 1

Disease: Rice Blast

Answer 1

Causal organism: Pyricularia oryzae

Question 2

Disease: Rice Sheath Blight

Answer 2

Causal organism: Rhizoctonia solani

Question 3

Disease: Corn Leaf Spot

Answer 3

Causal organism: Bipolaris maydis

Question 4

Disease: Peanut Leaf Spot

Answer 4

Causal organism: Cercospora arachidicola

Question 5

Disease: Peanut Rust

Answer 5

Causal organism: Puccinia arachidis

Question 6

Disease: Corn Rust

Answer 6

Causal organism: Puccinia polysora

Question 7

Disease: Panama Wilt of Banana

Answer 7

Causal organism: Fusarium oxysporum f. sp. cubense

Question 8

Disease: Black Sigatoka of Banana

Answer 8

Causal organism:
Mycosphaerella fijiensis (teleomorph)
Pseudocercospora fijiensis (anamorph)

Question 9

Disease: Mango Anthracnose

Answer 9

Causal organism: Colletotrichum gloeosporioides

Question 10

Disease: Stem End Rot of Mango

Answer 10

Causal organism: Lasiodiplodia theobromae

Question 11

Disease: Okra Leaf Mold

Answer 11

Causal organism: Cercospora abelmoschi

Question 12

Disease: Purple Blotch of Onion

Answer 12

Causal organism: Alternaria porri

Question 13

Anamorph

Answer 13

Stage: Asexual
Cell division: Mitosis
Spore production: Only asexual spores

Question 14

Teleomorph

Answer 14

Stage: Sexual
Cell division: Meiosis
Spore production: Both sexual and asexual spores

Question 15

Holomorph

Answer 15

whole fungus including anamorph and teleomorph
Stage: Asexual and Sexual
Cell division: Mitosis and Meiosis
Spore production: Asexual and Sexual spores

Question 16

Disease: Damping-off of Seedlings

Answer 16

Causal organism: Pythium spp.

Question 17

Disease: Corn Downy Mildew

Answer 17

Causal organism: Peronosclerospora philippinensis

Question 18

Disease: Gabi (Taro) Leaf Blight

Answer 18

Causal organism: Phytophthora colocasiae

Question 19

Disease: White Rust of Kangkong

Answer 19

Causal organism: Albugo sp.

Question 20

Aseptate

Answer 20

absence of septum or cross wall

Question 21

Catenate

Answer 21

In chain

Question 22

Conidium (pl. conidia)

Answer 22

Asexual spore

Question 23

Distoseptate

Answer 23

(of septation) heaving individual cellz surrounded by a sac-like wall distinct from the outer wall

Question 24

Doliiform

Answer 24

Barrel-like in form

Question 25

Falcate

Answer 25

Curved like the blade or a scythe

Question 26

Fascicle

Answer 26

In group

Question 27

Fusiform

Answer 27

Spindle-like, narrowing towards the end

Question 28

Hyaline

Answer 28

Colorless

Question 29

Lunate

Answer 29

Like new moon, crescentic

Question 30

Multiseptate

Answer 30

Having cross walls

Question 31

Obclavate

Answer 31

Inversely clavate widest at the base

Question 32

Obovoid

Answer 32

Inversely ovoid

Question 33

Papilla

Answer 33

Small rounded structures

Question 34

Pustule (pl. pustules)

Answer 34

Blister-like, frequently erumpent, spot or spore mass

Question 35

Sporangium (pl. sporangia)

Answer 35

An organ enclosing the spores

Question 36

Sporangiophore

Answer 36

Morphologically differentiated, subtending one or more sporangia

Question 37

Subglobose

Answer 37

Not quite spherical

Question 38

Uredospore (pl. uredospore)

Answer 38

‘Summer’ spore or repeating vegetative spore

Question 39

Disease: Bacterial Wilt of Solanaceous Crops

Answer 39

Causal organism: Ralstonia solanacearum

Question 40

Disease: Bacterial Blight of Rice

Answer 40

Causal organism: Xanthomonas oryzae pv. oryzae

Question 41

Disease: Soft Rot of Vegetables

Answer 41

Causal organism: Pectobacterium carotovorum

Question 42

Disease: Bacterial Blight of Anthurium

Answer 42

Causal organism: Xanthomonas axonopodis pv. dieffenbachiae

Question 43

Disease: Citrus Canker

Answer 43

Causal organism: Xanthomonas axonopodis pv. citri

Question 44

Disease: Huanglongbing / Citrus Greening

Answer 44

Causal organism: Candidatus Liberibacter

Question 45

Disease: Rice Orange Leaf

Answer 45

Causal organism: Candidatus Phytoplasma

Question 46

Disease: Cassava Witches’s Broom

Answer 46

Causal organism: Candidatus Phytoplasma

Question 47

Disease: Root Knot of Solanaceous Crops

Answer 47

Causal organism: Meloidogyne incognita

Question 48

Disease: Toppling / Blackhead Disease of Banana

Answer 48

Causal organism: Radopholus similis

Question 49

Disease: Corn Root Lesion

Answer 49

Causal organism: Pratylenchus spp.

Question 50

Disease: Tobacco Mosaic

Answer 50

Causal organism: Tobacco mosaic virus (TMV)

Question 51

Disease: Rice Tungro

Answer 51

Causal organism:
Rice tungro bacilliform virus (RTBV)
Rice tungro spherical virus (RTSV)

Question 52

Disease: Abaca / Banana Bunchy Top

Answer 52

Causal organism:
Abaca bunchy top virus (ABTV)
Banana bunchy top virus (BBTV)

Question 53

Disease: Papaya Ringspot

Answer 53

Causal organism: Papaya ringspot virus (PRSV)

Question 54

Disease: Tomato Leaf Curl

Answer 54

Causal organism: Tomato leaf curl Philippines virus (ToLPV)

Question 55

Disease: Rice Grassy Stunt

Answer 55

Causal organism: Rice grassy stunt virus (RGSV)

Question 56

Disease: Citrus Tristeza

Answer 56

Causal organism: Citrus tristeza virus (CTV)

Question 57

Disease: Potato Spindle Tuber

Answer 57

Causal organism: *Potato spindle tuber viroid (PSTVd)

Question 58

Disease: Cadang-Cadang Disease of Coconut

Answer 58

Causal organism: Coconut cadang-cadang viroid (CCCvd)

Question 59

Hosts: Cultivated trees particularly mango
May also parasitize neem, avocado, sapota trees, among others

Answer 59

Phanerogam: Loranthus philippinensis

Question 60

Hosts: Tomato, tobacco, legumes, trees, and shrubs

Answer 60

Phanerogam: Cuscuta sp.