Interactive effects of sulphur dioxide and mineral nutrient supply on photosynthetic characteristics and yield in four wheat cultivars

Field experiments were conducted on four cultivars of wheat (Triticum aesti vum L.) to examine the variability in cultivar response to sulphur dioxide (SO2) under different concentrations of mineral nutrients. Thirty-days-old plants were exposed for 8 weeks to 390+/-20 mu g m(-3) (0.15 ppm) SO2 for 4 h per day, 5 d per week. Decline in net photosynthetic rate, contents of p igments and nitrogen, biomass and grain yield of each cultivars were due to SO2 at all the nutrient concentrations studied. However, the magnitude of reduction was higher in plants grown without nutrient application. On the b asis of the reductions in photosynthesis and yield, the susceptibility of w heat cultivars to SO2 was in the order of Malviya 213 > Malviya 37 > Malviy a 206 > Malviya 234 at recommended dose of NPK, whereas the same without th e nutrients was Malviya 206 > Malviya 234 > Malviya 213 > Malviya 37.