Among the following, which one is the least water-efficient crop? ​

Correct answer: A (Sugarcane). Sugarcane is a long-duration crop, usually 10 to 12 months, and needs roughly 1500 to 2500 mm of water over its cycle. Its water footprint is also very high, around 200 cubic metres per tonne of cane on global averages. Per unit of output it is the most water-intensive of the four.

• B) Sunflower: A short-duration oilseed, about 3 to 4 months, needing roughly 500 to 650 mm. Comparatively water-efficient.
• C) Pearl millet (bajra): A C4 cereal that is highly drought-tolerant and needs only about 300 to 500 mm. Among the most water-efficient crops.
• D) Red gram (tur): A deep-rooted pulse that fixes nitrogen and needs about 600 to 650 mm. Low water demand relative to its protein output.

Core concept: Crop water productivity, meaning yield per unit of water used, and virtual water. This links to the Mains debate on crop diversification, millets under National Food Security and Nutrition agendas, and the Punjab-Haryana groundwater crisis linked to paddy and sugarcane.

Trap: Aspirants often confuse water-intensive with high-value or high-input crops. Sugarcane is a commercially important cash crop, but its water footprint is the highest of the options.