Effects of oxidants on soybean growth and yield in the Pakistan Punjab.
Plants of soybean (Glycine max L.) were grown with and without the ozone protectant EDU (N-[2-(2-oxo-1-imidazolidinyl)ethyl]-n2 phenylurea) at a suburban site, a remote rural site and a rural roadside site around the city of Lahore, Pakistan. The development and yield of the plants was determined in two experiments--one immediately post-monsoon and one in the following spring (pre-monsoon). Concentrations of nitrogen dioxide and photochemical oxidants were measured at each site. The effect on yield of EDU at the suburban site (47 and 113% increase in seed weight per plant relative to the untreated plants in the post- and pre-monsoon experiments, respectively) was similar to the effects of filtration on yield on soybean in a parallel open-top chamber study at the same site (77% increase relative to plants subjected to unfiltered air for the pre-monsoon experiment). Effects of EDU on yield were greater at both rural sites than at the suburban site in both experiments, and greater in the spring experiment (182% at the remote rural site and 285% at the rural roadside site) than in the post-monsoon experiment (94% at the remote rural site and 170% at the rural roadside site); oxidant concentrations were also greater at the rural sites than at the suburban site, and greater in the spring experiment than the post-monsoon experiment. The results imply that ozone may be causing significant crop losses in rural areas around Lahore; however, the geographical extent of the problem, and the implications for peri-urban agriculture around other cities of south Asia are uncertain.
Wahid
A
A
Department of Botany, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan.
Milne
E
E
Shamsi
S R
SR
Ashmore
M R
MR
Marshall
F M
FM
D000383:Agriculture; D000393:Air Pollutants / Q000009:adverse effects*; D000975:Antioxidants / Q000494:pharmacology; D007887:Fabaceae / Q000254:growth & development*; D010083:Oxidants, Photochemical / Q000009:adverse effects*; D010126:Ozone / Q000009:adverse effects*; D010671:Phenylurea Compounds / Q000494:pharmacology; D010946:Plants, Medicinal; D012424:Rural Population; D012621:Seasons
D000393:Air Pollutants; D000975:Antioxidants; D010083:Oxidants, Photochemical; D010671:Phenylurea Compounds; C032766:ethylene diurea; D010126:Ozone