Concept:Cultural practices in vegetable production are the routine field operations carried out to ensure good growth, yield, and quality of the crop.
Explanation:Vegetable production involves many field activities. These include mulching, weeding, fertilizer application, earthing-up, pruning, pest and disease control, and harvesting.
Mulching (III) is a cultural practice because it helps conserve soil moisture and control weeds.
Application of fertilizer (I) is also a cultural practice as it supplies nutrients to the crop.
Harvesting (II) is the final cultural practice of collecting the mature vegetable produce.
Thus, all three given activities are considered cultural practices in vegetable production.
Answer:D. I, II and III