Growth and yield of wheat(Triticum aestivumL.) with elevated atmospheric carbon dioxide and temperature in north-west India

Abstract

An experiment was conducted growing wheat (Triticum aestivum L.) in open top chambers (OTCs) to determine the effects of elevated atmospheric carbon dioxide (CO2) and temperature on growth, yield and yield attributes of wheat. Wheat (var. WR 544) was grown with two levels of carbon dioxide i.e., ambient (400 ppm) and elevated (550 ± 20 ppm) and three levels of temperature i.e., ambient, ambient + 1.5°C and ambient + 3.0°C during rabi (November to April) seasons of 2013–14 and 2014–15 in New Delhi, India. Elevated CO2 increased grain yield of wheat by 21.36% with greater grain number and harvest index (HI) by 6.56% compared to ambient CO2. Biological yield, straw yield and other yield attributes also increased with elevated CO2. Elevated temperature by 1.5°C and 3.0°C decreasedgrain yield by 9.39% and 18.18%, respectively. Simultaneous elevation of CO2 and temperature increased number of tiller m−2, number of spike m−2, straw yield, biological yield but decreased days to 50% anthesis, plant height, number of grains spike−1 and grain weight spike−1. The study showed that elevated CO2 had positive effects, whereas elevated temperature had negative effects on growth and yield of wheat. With elevation of both CO2 and temperature, elevated CO2 reduced the negative effects of elevated temperature on yield and yield components of wheat.