Effect of ozone stress on different stages of plant growth, yield and foliar emission of VOCs in some crop plants

Abstract

Surface ozone is one of the most damaging phytotoxic air pollutant causing serious newlinedamage to agriculture crops, trees and natural ecosystems. In present study elevated newlinesurface ozone levels, in confirmation of previous observations have been reported from newlineDelhi and environs. Surface ozone build up is likely to further increase in future because newlineof growing emission of precursors from different sources in Delhi and elsewhere. newlineVarious controlled as well as field dose response studies on elevated surface ozone newlinelevels have shown its adverse effects on growth and yield of crops. Response of crops to newlineelevated surface ozone levels varies throughout their lifespan also. In USA and newlineEuropean countries some studies have shown variations in different crop growth stages newlineresponse to ozone stress, but compared to dose response studies very few studies shed newlinelight on this aspect i.e., shifts in ozone sensitivity of crops with their growth stages. In newlineIndia also systematic studies have not been attempted with respect to the effect of newlinesurface ozone at different growth stages of crops. newlineThe present study was undertaken to determine the effect of ozone stress on different newlinegrowth stages of maize (Zea mays var.Ganga safed), potato (Solanum tuberosum newlinevar.Kufri jyoti), radish (Raphanus sativus var. Pusa chetaki) and tomato (Lycopersicon newlineesculentum var. Pusa ruby). Each crop at three different growth stages exposed to two newlinedifferent levels of ozone for 12 days and 2 hour per day. During the exposures crops newlinewere monitored for appearance of ozone injury symptoms and except maize in all three newlinecrops, visible ozone injury symptoms were appeared. For observing differences in newlinegrowth and yield performance, unexposed and exposed plants were harvested twice for newlineeach treatment. Half of the unexposed and exposed plants of each growth stage were newlineharvested (Harvest I) immediately following 12 days of ozone exposure and, finally at newlinematurity(Harvest II), remaining half of the unexposed and exposed plants of each newlinegrowth stage were harvested.