Yoshida - 1981 - Fundamentals of Rice Crop Science

96 FUNDAMENTALS OF RICE CROP SCIENCE
2.18. Monthly rainfall at 3 rice-growing areas in Asia.
The rainfall patterns of three Asian rice-growing regions illustrate the basic
patterns of rainfall distribution (Fig. 2.18):
• Lahore, Pakistan, represents a semiarid climate. The annual rainfall is
about 500 mm/yr, much less than the water requirement of a rice crop.
Hence, rice is grown only when irrigation is provided. Decan Heights in
the Indian subcontinent has a similar climate.
• Cuttack, India, has a typical dry and wet monsoon climate. Only one
monsoon brings most of the rainfall, and the wet season is distinct from the
dry. Rainfed rice cultivation is started in June and the crop is harvested
in November or December. Most rice-growing regions in South and Southeast
Asia have this type of climate. The duration of the rainy season and the
amount of rainfall, however, vary with location.
• Tacloban, Philippines, receives rain from two monsoons (northeast and
southwest). As a consequence, rainfall is fairly evenly distributed
throughout the year, and no regular dry season occurs. Under this type of
climate, rice can be grown throughout the year but harvesting and drying
may pose some problems.
These basic rainfall patterns could be further classified into subgroups. For
example, Kawaguchi and Kyuma (1977) proposed 9 climatic groups for tropical
Asia while Oldeman and Suardi (1977) considered 17 climatic zones related to
cropping patterns in Asia. For individual rainfall data, the reader is advised to refer
to handbooks of climatology or reports from local weather stations.