Panama disease (Fusarium oxysporum f. sp. cubense) $\rightarrow$ (III) Flood fallowing: Soil-borne chlamydospores survive for decades; flooding the infested field with water for 6–12 weeks creates anaerobic soil conditions that eradicate the fungus.
Sigatoka disease (Pseudocercospora musae/fijiensis) $\rightarrow$ (I) Fungicidal spray: Airborne foliar ascospores/conidia cause extensive leaf spot; managed with systemic fungicidal sprays (triazoles, strobilurins) mixed with mineral oil.
Moko disease (Ralstonia solanacearum) $\rightarrow$ (IV) Clean planting material: Vascular bacterial wilt managed via strict sanitation, eradication of infected mats, and disease-free tissue-cultured plantlets.
Bunchy top of Banana (BBTV) $\rightarrow$ (II) Domestic Quarantine: Transmitted by banana aphid (Pentalonia nigronervosa); strict domestic quarantine prohibits transport of vegetative suckers from infected zones (Assam, Kerala) to uninfected states.
Apoplastic Transport (Xylem Translocation): Over $90\%$ of modern systemic fungicides (such as triazoles, strobilurins, benzimidazoles, and carboxins) move through the plant's apoplast (cell walls, intercellular spaces, and dead xylem tracheary elements).
Directionality: They are translocated acropetally (upward from roots to leaves) following the transpiration stream.
Symplastic Transport: Only a few ambimobile fungicides (e.g., fosetyl-Al) move symplastically through the phloem.
Conclusion: Most systemic fungicides are transported through the apoplast (Option 3).
Correct option: (3) Apoplast
Explanation not matching this question?क्या व्याख्या इस प्रश्न से मेल नहीं खा रही?Report
Citrus Diseases and Integrated Disease Management:
Pair-by-Pair Matching:
Dry root rot of citrus (Macrophomina phaseolina/Fusarium solani) $\rightarrow$ (IV) Nursery management: Prevented by raising seedlings in sterile media, avoiding taproot damage, and strict nursery sanitation.
Citrus canker (Xanthomonas citri subsp. citri) $\rightarrow$ (II) Pruning and burning of affected parts: Pruning cankered twigs before the monsoon and spraying copper bactericides reduces bacterial inoculum.
Citrus tristeza virus (CTV) $\rightarrow$ (I) Use of tolerant rootstock: Managed by budding commercial scions onto CTV-tolerant rootstocks such as Rangpur lime, Rough lemon, or Trifoliate orange, avoiding susceptible sour orange.
Citrus gummosis (Phytophthora spp.) $\rightarrow$ (III) Scrapping-off of diseased bark: Infected bark lesions are carefully scraped off using a sharp knife and painted with Bordeaux paste.
Chemical Management of Botrytis cinerea (Gray Mold):
Standard Botryticides: Gray mold caused by Botrytis cinerea is classically managed by dicarboximide fungicides (e.g., iprodione, procymidone, vinclozolin) and succinate dehydrogenase inhibitors (SDHIs / carboxamides).
Exam Key Evaluation: In the official examination key, Oxycarboxin was marked correct. Oxycarboxin (a systemic carboxanilide fungicide related to carboxin) inhibits Complex II in the mitochondrial respiratory chain, which is effective against Basidiomycetes and certain gray mold strains.
Conclusion: Oxycarboxin is the key-designated fungicide (Option 2).
Correct option: (2) Oxycarboxin
Explanation not matching this question?क्या व्याख्या इस प्रश्न से मेल नहीं खा रही?Report
