Here are what I would say are the most important events that have to do with the Hawaiian sugar industry.
First of all, there was the beginning of the industry. Sugar was first planted on an industrial scale in Koloa (Kauai) in the 1830s. This was done by Ladd & Company.
I would say that the American Civil War was another big event. This caused the exports of sugar from Hawaii to the United States to skyrocket. Of course, they also fell when the war ended, so it was not a permanent thing.
I don't know if you would count this as having to do with the sugar industry, but the importation of workers to work in the plantations had a huge impact on Hawaii as a whole. The huge Asian population of the islands (as well as the Pidgin that so many locals speak) comes from all the importation of labor from Japan, China, the Philippines and other places.
Perhaps the most important event was the 1876 Reciprocity Treaty with the US. This let Hawaiian sugar into the US untaxed and led to a huge boom in trade. You could argue that this led pretty directly to the US annexation of the islands in the 1890s (I would say the annexation was connected to the sugar industry too).