• Epidemiology and Biology of Peach Leaf Curl (Taphrina deformans):
• is true: The fungus overwinters and carries over from season to season as resistant blastoconidia (yeast-like budding conidia) on the bark and dormant bud scales of peach trees.
• is true: Taphrina deformans is an ascomycete that produces naked asci lining the leaf surface, each containing eight primary ascospores that bud into conidia.
• is false: Leaf curl development is favored by cool, wet, rainy weather ($10-15^\circ\text{C}$) during bud break, NOT hot and humid climate.
• is false: Conidia are disseminated by rain splash and wind, NOT by psyllids.
• Conclusion: Features (A) and (C) only are true (Option 3).

Correct option: (3) (A) and (C) only.

• Diseases Caused by Phytophthora citrophthora:
• Citrus Gummosis (Foot Rot / Collar Rot): Caused primarily by Phytophthora citrophthora (and P. nicotianae var. parasitica).
• Symptoms: The pathogen attacks the bark near the soil line, causing water-soaking, brown rotting of the cambium, longitudinal bark cracking, and profuse exudation of dark amber-colored gum (gummosis), girdling the trunk and causing tree decline.
• Other Diseases: Mahali / Koleroga of arecanut is caused by Phytophthora meadii / P. heveae.
• Conclusion: Phytophthora citrophthora causes Gummosis (Option 3).

Correct option: (3) Gummosis

• Integrated Management of Purple Blotch of Onion (Alternaria porri):
• Cultural and Chemical Practices:
• Long crop rotation: Alternaria porri survives on infected crop residues; adopting a 2–3 year crop rotation with non-allium crops deprives the pathogen of host tissues.
• Well-drained field: Dense foliage and standing water promote leaf wetness; good field drainage and optimum spacing lower canopy humidity.
• Seed treatment with Thiram / Mancozeb: Eradicates seed-borne conidia and protects seedlings during emergence.
• Exclusion: Roguing individual plants in large field plantations is impractical against airborne conidia.
• Conclusion: Management involves (A), (C), and (D) only (Option 2).

Correct option: (2) (A), (C) and (D) only.