Rainfed rice - IRRI books - International Rice Research Institute

Moisture Availability, Water Balance and Crop Planning
This analysis points out that, in rainfed situations, because crop
establishment for crop varieties of all durations is fixed at a particular time,
long-duration varieties would suffer more from water stress conditions
during the reproductive and maturity stages than medium-duration
varieties. The experimental results with a set of two durations of rice
varieties and the moisture availability index analysis for different growth
stages of the two groups of varieties confirm this observation. The difference
in the required and available moisture index was the same for the seedling
and vegetative stages for the two varietal groups, whereas, at reproductive
and maturity stages, it was greater for the long-duration varieties than for
the medium-duration ones.
These results provide a basis for preparing production strategies and
cropping calendars, including the selection of technological components and
packages to be applied in planning resource allocations for this work. Such
an analysis also provides guidance for avoiding/minimising risks in rainfed
situations. This also directly feeds into the technology extrapolation
procedures and delineation of technology application domains.
Prepared by:
V. P. Singh
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