Sulfur has become an indispensable element for the modern industrial system including for agriculture. Before the outbreak of the Iran war, 24 percent of the world's supply of sulfur passed through the Strait of Hormuz. I can find no reliable information on whether sulfur is being shipped through the strait now after the Iranian government claimed control. I suspect the amount is close to zero.
The sulfur price at the start of the Iran conflict was approximately $500 per metric ton for sulfur originating from the the Middle East. It now sits above $800. Some customers paid more than $1,000 in June for Canadian-origin sulfur, a record. These high prices are threatening worldwide phosphate fertilizer supplies which depend on sulfuric acid for their production. To understand why this is happening, it's important to have some background.
In the densely interconnected web of global production, sulfur sits in the middle as the basis for sulfuric acid, a chemical that finds wide application in industry including for improving octane in gasoline; as raw material for detergents, resins, dyes, and explosives; for the "pickling" of metals, that is, the removal of oxidation from the surface; as an electrolyte in lead-acid batteries; as a laboratory reagent, that is, a chemical used for analysis and synthesis of chemicals; and for the production of phosphate fertilizer, an essential plant nutrient critical to obtaining high yields in today's industrial agricultural system. In fact, 50 percent of all sulfuric acid is used to make fertilizers, 42.5 percent to make phosphate fertilizer and 7.5 percent to make ammonium sulfate (a source of nitrogen) and sulfur fertilizer products. (Sulfur is an important soil nutrient by itself.)