Relationship between AOTX Indices and Crops Response towards Ozone Concentration in Malaysia

The purpose of this study was to analyze the contributions of ozone to different AOT indices, which were
AOT0, AOT5, AOT10, AOT15, AOT20, AOT25, AOT30, AOT40, and AOT50 in Kedah, Malaysia. Besides
that, this study was aimed to test the response of crops towards these different AOT indices, under the
Malaysia climate. Environmental parameter that was employed in the study was the ozone concentration. This
data was analyzed from 7a.m to 7p.m every day from year 2004 to 2006. From this study, AOT0 was
considered to be a control index. The present results demonstrated that AOT50 gave the highest response on
crops under the Malaysia climate. Therefore, this study suggests that AOT50 of 1777.5 ppb.h are the most
critical AOTX indices towards the crops response to ozone in Malaysia. This result however, was different
from AOT40 of 3000 ppb.h, which is recommended for crops in European countries.