Unit 5: Nematode Pests of Crops - Practice Quiz

1 Which nematode causes white-tip disease of rice?

2 Which nematode is commonly known as the rice root nematode?

3 Ufra disease of deep-water rice is caused by which nematode?

4 Which nematode causes ear-cockle disease of wheat?

5 The cereal cyst nematode commonly associated with wheat is:

6 Which group of nematodes commonly produces visible galls on vegetable roots?

7 Which species is a widely distributed root-knot nematode of tomato, brinjal, and okra?

8 Globodera rostochiensis is an important pest of which vegetable crop?

9 Which cyst nematode is an important pest of pigeonpea?

10 Root-knot nematodes reduce pulse crop growth mainly by damaging which plant part?

11 Which nematode is commonly associated with root-knot disease in groundnut and other oilseed crops?

12 The reniform nematode that attacks several oilseed crops is:

13 Which nematode is a major pest of cotton in many warm regions?

14 Which nematode causes slow decline of citrus?

15 Which nematode is commonly called the burrowing nematode of banana?

16 Severe root damage caused by Radopholus similis can make banana plants more likely to:

17 Which root-lesion nematode is an important pest of tea?

18 Which root-knot nematode is well known as a pest of coffee?

19 Which plant part is primarily attacked by most economically important nematode pests of coconut?

20 Which material commonly spreads plant-parasitic nematodes from one field to another?

21 A rice field shows stunted plants with poor tillering, and infected panicles emerge partially or fail to emerge. Which nematode is most likely responsible?

22 Rice seedlings develop chlorotic leaf tips and reduced growth, while the nematode is commonly carried in contaminated seed. Which pest is indicated?

23 In a wheat field, plants occur in patches and show yellowing and poor growth. Examination reveals lemon-shaped cysts attached to roots. Which nematode is most likely present?

24 Wheat grains are replaced by dark, nematode-filled galls that can contaminate harvested seed. Which pest is associated with this symptom?

25 Tomato plants are stunted despite adequate fertilizer, and roots contain numerous galls. Which management practice would most directly reduce the main nematode problem?

26 A vegetable grower notices that carrots are forked and market value is reduced, although above-ground symptoms are slight. Which nematode group commonly produces this problem?

27 Pigeonpea plants show yellowing and poor growth in patches, and females with a swollen body are attached partly to the roots. Which nematode is most likely involved?

28 A farmer repeatedly grows chickpea in the same field, and plants now show root galling and poor nodulation. Which explanation best accounts for the reduced crop performance?

29 Groundnut plants are uneven in height, have yellow foliage, and show swollen roots with reduced pod development. Which nematode problem is most consistent with these symptoms?

30 Soybean plants in a dry field remain stunted even after irrigation, and roots contain many small females with a swollen posterior end. Which nematode is suggested?

31 Cotton plants show stunting, yellowing, and root galls. Which combination represents important nematode pests that may be involved?

32 A cotton field has poor plant establishment after seedling emergence, and roots have lesions rather than distinct spherical galls. Which feeding type is most likely responsible?

33 Citrus trees show gradual decline, sparse foliage, and reduced fruit size. Fine roots are damaged, but large root galls are absent. Which nematode is most likely associated with this condition?

34 Banana plants lodge easily during strong winds, and roots show dark lesions and internal tissue damage. Which nematode is commonly linked with this condition?

35 A banana plantation is replanted using suckers from an infested field, and disease appears rapidly in the new area. Which factor most directly explains this spread?

36 Tea bushes have reduced feeder roots, poor shoot growth, and gradual decline in a continuously cultivated area. Which nematode is a likely cause?

37 Coffee seedlings show stunting and root galls in a nursery bed. Which management decision would be most appropriate before transplanting?

38 Coconut palms in a plantation show reduced growth and root injury after infested planting material was introduced. Which nematode is associated with red-ring disease of coconut and palms?

39 A nematode pest is detected in a new region after movement of infested soil attached to farm machinery. Which characteristic of nematodes is most relevant to this type of distribution?

40 A root-knot nematode population becomes more damaging in a warm, irrigated field than in a cool, poorly drained field. Which factor best explains this distribution pattern?

41 A rice crop raised from a particular seed lot develops white, necrotic leaf tips, twisted flag leaves, and partially filled panicles. Roots lack terminal galls, and numerous slender nematodes are recovered from beneath the glumes of stored seed. Which diagnosis best integrates these observations?

42 In a continuously flooded rice field, plants exhibit reduced tillering and extensive brown cortical lesions. Vermiform adults and juveniles occur within the roots, but neither terminal hook-shaped galls nor swollen sedentary females are found. Which nematode is most consistent with the evidence?

43 Direct-seeded rice is grown aerobically for three weeks and then flooded. At midseason, affected roots show distinctive terminal hooks, while sedentary females are embedded in the swollen tissue. Which interpretation is most defensible?

44 A wheat field contains ear-cockle seed galls as well as yellow, sticky exudate on malformed ears. Which relationship most accurately explains the combined syndrome?

45 A field heavily infested with the cereal cyst nematode is rotated out of wheat for one year. Which program is most likely to reduce Heterodera avenae multiplication rather than merely postpone crop damage?

46 Potatoes from a cool highland field show patches of early senescence. Small white and yellow females occur on young roots, while brown spherical bodies containing viable eggs persist after harvest. Which regulatory response addresses the principal long-distance dispersal pathway?

47 A tomato cultivar carrying the Mi-1 resistance gene suppresses root-knot nematodes in spring but develops severe galling when soil temperatures remain above approximately . Molecular tests show no change in the nematode population. What is the most likely explanation?

48 An onion-storage facility receives bulbs with swollen, distorted scales. Microscopy reveals a migratory nematode, and dense aggregations survive desiccation in dried tissue as "nematode wool." Which management action most directly interrupts carryover?

49 Pigeonpea plants are stunted in discrete patches. Roots bear pinhead-sized lemon-shaped females that later become brown, egg-filled cysts; conspicuous root galls are absent. Which pest and feeding strategy fit this diagnosis?

50 In a soybean cyst nematode test, only indicator line 2 has , while the susceptible check has ; all other indicator lines have female indices below 10. Using and a positive threshold of , how should the population be designated?

51 Cotton plants show uneven stunting without prominent root galls. Mature females have their anterior region embedded in the root, while the enlarged posterior protrudes outside and becomes kidney-shaped. Which nematode is implicated?

52 Declining citrus trees have sparse feeder roots coated with adhering soil particles. Adult females are partly embedded in the root cortex, while their posterior ends remain outside and deposit eggs in a gelatinous matrix. Which diagnosis is most appropriate?

53 When sampling a citrus orchard affected by slow decline, the most severely declining centers of old patches yield fewer Tylenchulus semipenetrans juveniles than moderately affected patch margins. Which interpretation is strongest?

54 A banana plantation experiences toppling during moderate winds. Cross-sections of roots contain sharply defined reddish-brown to black cortical lesions, and vermiform males, females, and juveniles are recovered from within the lesions. Which pest is the primary suspect?

55 A grower establishes a new banana field in nematode-free soil but uses untreated suckers from an infested plantation. Within a year, lesions radiate outward from planting sites. Which prevention strategy would have offered the strongest initial protection?

56 Tea bushes show progressive loss of feeder roots and dark necrotic lesions rather than discrete galls. All vermiform stages occur within the cortex, indicating repeated entry, migration, and exit. Which nematode best matches this pattern?

57 Two coffee nurseries show comparable above-ground decline. Nursery I has small root galls containing sedentary swollen females; Nursery II has elongated necrotic lesions containing vermiform stages. Which pairing best explains the contrast?

58 Coconut palms show a brick-red ring in transverse stem sections, followed by crown decline. The disease occurs where the palm weevil Rhynchophorus palmarum is established. Which pest relationship is responsible?

59 A quarantine survey assumes that 10% of independently selected soil units in an infested field contain detectable cysts. What minimum number of units must be tested to obtain at least 95% probability of detecting the pest, using ?

60 A nematode previously absent from a production region is found in genetically similar populations clustered around nurseries supplied by one propagator. It is absent from comparable fields lacking that supplier's stock. Which hypothesis best explains the observed distribution?