Exclusion of UV-B radiation from normal solar spectrum on the growth of mung bean and maize

Abstract

The increase in UV-B radiation due to depletion of the ozone layer has potentially harmful effects on plant growth and performance. The bulk of these studies conducted in growth chambers, greenhouses or in the field use different types of exposure systems which may be responsible for differences in the sensitivity of a crop to UV-B radiation. A field study using selective filters to remove the UV-B portion of the solar spectrum was conducted with mung bean (a dicotyledonous C₃ plant) and maize (a monocotyledonous C₄ plant) to determine the sensitivity of these crop plants to ambient UV-B levels without disturbing the microenvironment. Mung bean was found to be sensitive to ambient UV-B levels in terms of leaf area development, plant height attained and net photosynthesis, while maize was found to be unaffected by ambient UV-B levels (22.8 |GmW cm^-2 nm^-1) found in Delhi, India (28°38'N, 77°13'E). The level of ambient UV-B radiation thus appears to be inhibitory for optimal growth of plants, especially dicotyledonous mung bean.