Elimination by plant use-category:
Amla (Indian gooseberry) is valued chiefly as a source of vitamin C in nutraceuticals, not as a crop-protection agent. Sunflower is primarily an oilseed crop with no recognised fungicidal compound extracted from it. Asparagus is a vegetable crop with no notable role in pest or disease management products. Neem, on the other hand, yields azadirachtin and related limonoids from its seeds and leaves, compounds with well-documented antifungal as well as insect growth-regulating activity, which is why neem-based formulations are registered and used against fungal diseases such as powdery mildew in organic and integrated crop-protection programmes.
Therefore, the fungicide is obtained from neem.