Unit 3: Formulations of biopesticides - Practice Quiz

1 What is the main purpose of formulating a microbial biopesticide?

2 Which component provides the pest-controlling activity in a microbial biopesticide?

3 What is the main role of a carrier in a microbial biopesticide formulation?

4 Which material is commonly used as a carrier in powder formulations of microbial biopesticides?

5 What does the abbreviation WP commonly mean in biopesticide formulations?

6 How is a wettable powder formulation generally prepared for field application?

7 Which formulation consists of larger solid particles that are usually applied directly to soil?

8 In a liquid microbial formulation, the microorganism is commonly dispersed in which type of medium?

9 What is a suspension concentrate?

10 Why is a carrier often sterilized before adding the microbial culture?

11 Why should a heat-sterilized carrier be cooled before microbial inoculation?

12 What is commonly produced before a microbial culture is mixed with a carrier?

13 Why is gentle drying preferred when preparing many microbial biopesticide powders?

14 Why is excess moisture undesirable in many dry microbial formulations?

15 What is the function of a surfactant in a sprayable microbial formulation?

16 What is the purpose of adding a sticker to a microbial biopesticide formulation?

17 Why may a UV protectant be included in a microbial biopesticide formulation?

18 Why is thorough mixing important during the preparation of a microbial formulation?

19 Which quality test estimates the number of living microorganisms in a formulation?

20 Which packaging is most suitable for protecting a dry microbial formulation from moisture?

21 A wettable powder formulation of Bacillus thuringiensis is prepared primarily to ensure that the product can be dispersed in water before spraying. Which component is most important for improving its ability to remain uniformly suspended?

22 During preparation of a microbial wettable powder, the carrier is selected mainly because it can improve handling, dilution, and stability. Which carrier property is most desirable?

23 A producer wants to prepare a microbial suspension concentrate containing viable fungal spores. Which processing condition should be avoided because it may reduce spore viability?

24 An oil-based formulation is selected for an entomopathogenic fungus intended for use during a dry period. What is the main expected advantage of this formulation?

25 A microbial granule is designed to release its active ingredient gradually in soil. Which formulation feature most directly controls the release rate?

26 When preparing alginate beads containing entomopathogenic nematodes, calcium chloride is commonly used after mixing the nematodes with sodium alginate. What is its function?

27 A formulation containing live bacteria develops a rapid decline in colony-forming units during storage. Which change is most likely to improve stability?

28 Why is moisture content carefully controlled during preparation of a dry microbial formulation?

29 A producer adds a wetting agent to a microbial spray formulation. What problem is this additive intended to reduce?

30 A microbial formulation forms hard lumps after storage and cannot be dispersed properly in water. Which preparation or storage issue is the most likely cause?

31 Which formulation is generally most appropriate when a microbial insecticide must be applied with ordinary farm spraying equipment after dilution in water?

32 A formulation scientist is choosing between a water-based and an oil-based formulation for a fungus whose spores germinate poorly in free water. Which choice is more suitable?

33 A microbial product is intended for application against soil-dwelling insect larvae. Which formulation would usually provide better placement near the target zone?

34 Why are pH and temperature monitored while preparing a liquid microbial formulation?

35 A formulation containing a virus-based biopesticide is dried by a method that removes water at low temperature under reduced pressure. Why can this method be useful?

36 A sticker is included in a microbial formulation intended for foliage application. What field problem is it mainly intended to address?

37 During preparation of a microbial formulation, a preservative is considered for extending shelf life. What must be confirmed before its use?

38 A suspension concentrate settles during storage but becomes uniform again after gentle shaking. Which quality characteristic does this observation primarily demonstrate?

39 A producer wants to reduce ultraviolet damage to fungal conidia in a foliar formulation. Which formulation strategy is most appropriate?

40 Why should microbial biomass be mixed with the carrier under controlled conditions during dry formulation preparation?

41 A conidial concentrate contains viable conidia per gram. Processing causes a 20% loss of viability. How much concentrate is required to prepare 100 kg of wettable powder containing viable conidia per gram?

42 Which process sequence best minimizes viability loss while preparing a wettable powder from shear- and heat-sensitive fungal conidia?

43 A fungal wettable powder wets completely within 20 seconds, but only 35% of its conidia remain suspended after the standard suspensibility test. Viability is unchanged. Which reformulation most directly addresses the failure?

44 Hydrophobic fungal conidia lose viability rapidly in aqueous suspension but remain stable under dry conditions. Which formulation strategy is most appropriate for foliar spraying?

45 A concentrated bacterial suspension develops a compact sediment that cannot be redispersed after storage, although viability and mean particle size remain acceptable. What is the best formulation adjustment?

46 A nucleopolyhedrovirus formulation must retain occlusion-body activity after field application on foliage. Which preparation approach best addresses its principal environmental and chemical vulnerabilities?

47 A microbial suspension concentrate is stable in deionized water but flocculates immediately when diluted in hard water rich in and . Which modification is most rational?

48 Under Stokes-type settling conditions, a reformulation halves the particle diameter and doubles the continuous-phase viscosity without changing density difference. What is the approximate new settling velocity relative to the original?

49 Which rheological profile is most desirable for a microbial suspension concentrate that must resist sedimentation during storage but remain easy to pour and spray?

50 Which sequence correctly prepares calcium-alginate microbeads containing a microbial biopesticide?

51 During spray drying of a bacterial biopesticide, inlet temperature is high but viability correlates more strongly with outlet temperature and residence time. Which intervention should be evaluated first?

52 Which lyophilization protocol is most likely to preserve vegetative bacterial cells that are sensitive to freezing and desiccation?

53 Water-sensitive conidia must be converted into water-dispersible granules, but preliminary wet extrusion causes major germination loss. Which alternative is most defensible?

54 A microbial seed-coating formulation is compatible with the seed but loses viability when applied over a conventional fungicidal treatment. Which development strategy best addresses the interaction?

55 An entomopathogenic fungus is being formulated as a soil-applied granule. Which carrier profile best balances storage stability and release after application?

56 A 100 kg formulation must contain CFU/g and 20 kg of inert carrier. Active lot A contains CFU/g, while active lot B contains CFU/g. Assuming no processing loss, which blend meets the target?

57 Viable count in a microbial formulation follows first-order loss, . If CFU/g, the minimum specification is CFU/g, and week, when is the specification reached?

58 Two bacterial formulations have identical microscopic particle counts, but one gives substantially lower mortality in the target insect. Which release specification would best distinguish biologically useful product from inactive material?

59 A preservative prevents bacterial contamination in a mixed formulation of bacterial spores and fungal conidia. The spores remain viable, but fungal germination falls below specification. What is the best pre-scale-up decision?

60 Calcium-alginate microcapsules retain excellent microbial viability, but target-insect mortality is delayed because release after application is too slow. Which modification most directly accelerates release?