ABSTRACT
RiceistheprincipalfoodgrainofMonsoonAsia.Throughoutthehotter, wetterareasofthesouth,includingsouthernJapan,theYangtzeand Gangeslowlands,muchofpeninsularIndiaandalmostallSouth-east Asia,thealluviallandpresentsamonotonouspatternofrectangular paddyfields.Wheretherainfallisadequateforrice,butrestrictedtoa sharplydefinedwetseason,themainricecropisplantedsothatitcan growwhenthefieldsarefloodedbyrainwater(oftensupplementedby naturalfloodwaterandmorerarelybyirrigation),andtheharvesttakes placebetweenNovemberandJanuaryafterthewaterhasdrainedaway. InMalayaandmuchofIndonesia,wheredryseasonsareshortornonexistent,somericeisalwaysreadyforreaping,thoughmostofthe harvestingisarrangedtocoincidewiththerelativelydrymonths.In MalayathosemonthsarebetweenOctoberandMarchwhenthedaysare shortest.Theannualrangeinthedurationofdaylightisslight,onlynine minutesatSingapore,increasingto37minutesatAlorStar,butmany kindsofricearesensitivetothatrangeandwillfloweronlyintheperiod ofshorterdays.Goodcropsareraisedonterracedhillsideswhereindividualfieldsmightbeasnarrowasfourfeet.Eveninthedrierpartsof thesesouthernareasitisapopularcropwhereverirrigationwateris available.
