Photosynthetic rate and water use efficiency (WUE) are crucial for the sustainable use of water in agriculture. Our objective was to analyze the variability of photosynthetic and related traits in maize ( Zea mays L.) and other summer crops in a temperate humid area. We evaluated photosynthetic parameters in maize for three years and compared them to pigeonpea and chickpea, adapted to arid environments, and pepper, tomato and...