NEW DELHI: Rising onion prices in India pose a greater risk to Prime Minister Narendra Modi’s government than a recent spike of 700% in tomatoes, forcing authorities take fresh steps to contain food inflation before key polls. India has imposed a 40% export tax on onions and plans to sell them locally at subsidized rates. The vegetable stands alongside tomatoes and potatoes as part of a trio of crops so crucial to Indian diets that past price spikes due to crop losses have prevented some ruling parties from...