The critical stages in rice with respect to irrigation are (A) Crown Root Initiation (CRI) and flowering (B) Sprouting and Panicle initiation (C) Early tillering and flowering (D) Ripening and maturity

Correct option is B

The correct answer is (C) C only

Explanation:
• In rice cultivation, critical stages are those growth periods where water stress (either deficit or excess) causes the maximum reduction in grain yield.
• The most sensitive stages for rice are Panicle Initiation, Flowering (Anthesis), and Early Tillering.
• During Early Tillering, adequate water is essential to ensure a high number of effective tillers, which directly determines the potential number of panicles.
• Flowering is the most critical stage of all; water stress at this time leads to high spikelet sterility and a drastic drop in yield.
• While the question lists "Early tillering and flowering" in part (C), it is important to note that Panicle Initiation (part B) is also critical, but the combination in (C) is the most standard answer for irrigation sensitivity in GS exams.

Information Booster:
• CRI (Crown Root Initiation) is the most critical irrigation stage for Wheat, not rice.
• For Rice, the water requirement is usually highest from panicle initiation to the milk stage.
• Puddling in rice is done to reduce percolation losses and create an anaerobic environment favorable for rice growth.

Additional Knowledge:
• Option A: CRI is specific to wheat (usually 21 days after sowing).
• Option D: Ripening and maturity require much less water; in fact, irrigation is typically stopped 10-15 days before harvest to facilitate ripening and field drying.