Relationships between Global Climate Indices and Rain-fed Crop Yields in Highland of South-Central Java, Indonesia

Abstract

Although there has been a high interest ωinvestigate the relationship between climate and crop yields in Indonesia， little evidence is available for crops in highland of the ∞untry・百risstudy evalu- ates the relationships between global clima飴 indices(80uthem Oscillation lndex， 801; sea surface temperature， 88T) and rain-fed crop yields in Gunungkidul district， highland of South-Central Java. Principal Component Analysis (PCA) approach was used to summarize the averaged SSTs d凹 mg planting season for the El Nino monitoring regions: IOBW (lndian Ocean Basin-Wide)， Ni亘o.West 釦 dNino.3. Crops yield of each sub-district of the area was detrended using a 5・ yearmovmg average ωenhance reliability of the da也. For some sub-districts， the first principal component of SSTs was negatively∞π'elated句 cropyield residuals of com and soybean while 801 was posi “ vely correlatedω 出atofcomand也yl組 dpaddy. Key