Assessment of ozone effects on local rice cultivar by portable ozone fumigation system in Hanoi, Vietnam

摘要

This study examined the effects of troposphere ozone (O_3) on rice by developing a portable ozone fumigation system and applied to the field in Hanoi, Vietnam. The system was nearly identical to the open top chamber but designed to easily and cheaply assess the O_3 sensitivity of local agricultural crops in the actual field. The rice (Oryza sativa L.) was exposed to ozone during the flowering stage at peri-urban experimental site of Hanoi. The fumigation protocols covered five different levels, namely; non-filtered air (ambient) as the control treatment, 32, 62, 85 and 113 ppb in 7-h mean. It was found that observed impacts corresponded well to similar open-rntop chamber studies in other Asian countries. The methodology and the system left a large room for improvement and called for very careful interpretation and pre-conditions (e.g. low ambient O_3 concentration). However, the portable O_3 exposure in the field might open a door to the less developed countries to implement the phytotoxic risk assessment of the local agricultural species.