Relative Photochemical Oxidant Sensitivity of Agricultural and Horticultural Plants

Abstract

In order to contribute to policy for the improvement of polluted atmospheric environment and the maintenance or the increase of crop productivity, we reviewed many reports relating foliar injury and the growth and yield loss caused by protochemical oxidants (ozone and peroxyacetyl nitrate (PAN)) and tried to decide ranking relative oxidant sensitivity of agricultural and horticultural plants in species and cultivars.
1. The list of relative ozone sensitivity of agricultural and horticultural plants by estimating foliar injury
Relative ozone sensitivity of agricultural and horticultural plants were classified by powered dose ((concentration) ² × exposure duration) which produced foliar in jury in ozone exposure experiments. As a result, spinach, radish, tobacco, morning glory and weilh onion were the most sensitive plant to ozone, peanut, tomato, soybean and rice were succeeded, and cauliflower, gladiolus andcabbage were the most resistant one.
2. The list of relative PAN sensitivity of agricultural and horticultural plants by estimating foliar injury
The most sensitive plant to PAN was petunia and white-flowered petunia was in jured by 4-5 hr exposure to 4-5 ppb of PAN in the polluted atmosphere. Crisp head lettuce, butter head lettuce, kidney bean, spinach, leaf beet and tomato were relatively sensitive plants, and radish and corn were the most resistant ones.
3. The list of relative ozone or PAN sensitivity of agricultural and horticultural plants in cultivars by estimating foliar injury
Differential ozone or PAN response exist not only among individual species but also among cultivars of single species. The large difference in the relative ozone sensitivity of many plants such as tobacco, kidney bean, soybean and rice cultivars has been extensively examined. On the other hand, little is known about differential cultivar sensitivity of plants by PAN. Sensitivity of petunia to PAN varied widely between cultivars and strains and white-flowered petunia was most sensitive of various colored ones.
4. The list of relative oxidant (ozone) sensitivity of agricultural and horticultural plants by estimating growth and yield loss
In Japan, there are several reports of the growth and yield loss of crops caused by photochemical oxidants in the field using open-top chambers and filtered air chambers or by low level ozone in the long term exposure experiments, but little is known about data comparable to the growth and yield loss among crop species. In America, National crop Loss Assessment Network (NCLAN) was conducted to provide accurate data on air pollution-induced losses to agriculture using open-top field chambers from 1980 to 1987. Results of the 8 year research showed that, when yields between the background ozone concentration of 0.025 ppm (seasonal 7 h day mean) and 0.06 ppm (seasonal 7 h day mean) exposures were compared, the order of yield losses of crops was as follows: turnip (24%)>soybean (17%)>spinach (14%)>wheat (11%)>cotton (10%)>corn (3%).