Ukraine was known as "the breadbasket of Europe" and the majority of the crops grown there were exported. In particular, grains such as wheat, corn and barley p

Ukraine was known as "the breadbasket of Europe" and the majority of the crops grown there were exported. In particular, grains such as wheat, corn and barley provide approximately 10% of the world's supply. From what I understood of the news, the exports weren't massively affected in the first year or so of the war due to a treaty with Russia that protected ships transporting grain from attack. In the last couple of months, Russia announced they weren't renewing that (yearly) treaty and would treat foreign ships transporting as if they were warships, and so viable military targets. As Russia has long had a massive sea base at Sevastopol in the south-west of Ukraine (when it gave Crimea to Ukraine in 1954, this base was kept as Russian territory due its significant influence over the Black Sea), this base is now a choke point for all sea vessels in and out of Ukraine, which is probably why Ukraine is now stepping up attacks here - because with the ending of the treaty, they need that export route to stay open. That last paragraph was a long winded way of saying that actually, until recently, the war in Ukraine shouldn't have affected the price of grain all that much, because it was largely continuing as before, so any prior price increases being blamed on the war were possibly just opportunistic. With the ending of the treaty, it's not unlikely that there will be significantly less grain exported, or more exported over land, and so the price could increase. Obviously in the situation where demand exceeds supply, price increases aren't proportional to the reduction in supply, but based on the willingness of buyers to pay more than someone else to secure their supply, so the increases will probably be more dramatic.