Water Management in Crops Questions and Answers

Answer: B

Surface drip is the micro-irrigation system most commonly adopted in India, where emitters are laid on the ground along the crop rows.

Bubblers, micro sprinklers and subsurface drip are used much less widely, since they are more costly or suited to special cases.

In India most drip systems are laid on the soil surface, with emitters near each plant, because they are cheaper and easier to install and maintain than subsurface lines. This is why surface drip is the most common type.

Answer: A

The most critical stage is Crown Root Initiation (CRI).

About 20 to 25 days after sowing, wheat forms its crown roots, which anchor the plant and absorb most of its water and nutrients. Missing irrigation at this stage cuts tillering and yield more than at any other stage, so the first irrigation is always timed for CRI.

Tillering, flowering and milk stages also need water, but agronomists rank CRI as the single most critical.

Answer: C

Pre-flowering is a critical stage for irrigation in Gram.

Gram (chickpea) is a rabi pulse usually grown on conserved moisture. If one irrigation is available, it is given at the pre-flowering (branching to flower initiation) stage, and if two, the second at pod development. Moisture stress then reduces flowering and pod set.

Wheat's first critical stage is crown root initiation, about 21 days after sowing. Potato is most sensitive at stolon formation and tuber initiation, and for mustard the critical stages are usually given as flowering and siliqua formation.

Answer: C

The critical stage among the options is Early tillering.

Rice is sensitive to water stress at several stages: early tillering, panicle initiation, booting and flowering. Stress during tillering reduces the number of productive tillers and so the number of panicles, which is why early tillering is listed as a critical stage for irrigation.

Crown root irrigation refers to wheat's first critical irrigation, not rice. Sprouting is not an irrigation stage of the transplanted crop, and tasselling (spelt 'Tarselling' in the paper) is the critical stage of maize.