Correct option is D
✅ (d) Soil borne disease: • Crop rotation helps break the life cycle of soil-borne pathogens (like fungi, nematodes, bacteria). • Example: Rotating cereals with legumes reduces Fusarium, Rhizoctonia, and nematode problems. • It reduces disease inoculum load in the soil.
❌ (a), (b), (c): • These are not effectively managed by rotation alone. Seed and air-borne diseases require other control methods.