The correct answer is (D) Alternaria blight.
Let's break down each option:
(A) White rust: This is a disease caused by a fungal pathogen, Albugo candida, which affects the rapeseed-mustard crops. Although it's a disease and not a pest, it is a common issue for these crops.
(B) Stalk borer: This is a pest that attacks the stems of rapeseed and mustard plants. The larvae feed on the stems and cause significant damage.
(C) Aphids: These are pests that suck sap from the plants, weakening them and making them more susceptible to diseases. Aphids are common pests of rapeseed and mustard crops.
(D) Alternaria blight: This is a fungal disease caused by the Alternaria fungus, which affects rapeseed-mustard crops. However, it is not a pest; rather, it is a disease that affects the plant’s leaves, stems, and pods.
Thus, Alternaria blight (option D) is a disease, not a pest, and is the correct answer.
Alternaria blight is a fungal disease affecting rapeseed-mustard crops, whereas the others listed (White rust, Stalk borer, Aphids) are pests.
| LIST I Weed type | List II Meaning | ||
| A | Annual weed | I | They occur almost at any time of the year |
| B | Biennial weed | II | They require more than two years to complete |
| C | Perennial weed | III | They live for two seasons |
| D | Multi season weed | IV | They grow, mature within a season |
| List-I (Name of crop) | List-II (Disease of crop) |
| (A) Paddy | (I) Red rot |
| (B) Cotton | (II) Loose smut |
| (C) Groundnut | (III) Tikka (Leaf spot) |
| (D) Gram | (IV) Rust |
Select the statements that are CORRECT regarding patterns of biodiversity.
Which of the following hormone is not produced by placenta ?
List - I | List - II | ||
| A | Streptokinase | I | Blood-Cholestrol lowering agents |
| B | Cyclosporin | II | Clot Buster |
| C | Statins | III | Propionibacterium sharmanii |
| D | Swiss Cheese | IV | Immuno suppressive agent |
Which of the following option determines percolation and water holding capacity of soils ?