India, the world’s second largest producer of wheat, has banned all exports with immediate effect after a heatwave affected the crop. A notice in the government gazette by the directorate of foreign trade, dated Friday, said a rise in global prices for wheat was threatening the food security of India and neighbouring and vulnerable countries. A key aim is to control rising domestic prices. Global wheat prices have increased by more than 40% since the beginning of the year. Before the war, Ukraine and Russia accounted for a third of global wheat and barley exports. Since Russia’s 24 February invasion, Ukraine’s ports have been blocked and civilian infrastructure and grain silos destroyed. At the same time, India’s own wheat harvest has suffered a record-breaking heatwave that is stunting production. Even though it is the world’s second largest producer of wheat, India consumes most of the wheat it produces. It had set a goal of exporting 10m tonnes of the grain in 2022-23, looking to capitalise on global disruption to wheat supplies from the war and find new markets for its wheat in Europe, Africa and Asia. Much of that would have gone to other developing countries such as Indonesia, the Philippines and Thailand. Apart from problems with weather damaging harvests, India’s vast stocks of wheat – a buffer against famine – have been strained by distribution of free grain during the pandemic to about 800 million people. To balance supply and demand, the government needs about 25m tonnes of wheat each year for an extensive food welfare programme that usually feeds more than 80 million people.