Warehouse was responsible for the levy of Phasi Pak Reua on foreign merchant ships, which had been the major revenue for the royal court. Akon (); taxes imposed on specific kinds of commodity such as rice, fruits and beverages. Rice producers were charged with two thangs of rice per one rai of agricultural land. The rice fields belonging to the nobility were exempted until the reign of King Rama III. Other specific kinds of products were levied included sugarcane, indigo, green beans, soybeans, sesame, tobacco, lemon basil, onions, turmeric, jutes, tamarinds, bananas, mangoes, betel nuts, coconuts, durians, oranges, etc. The largest Akon revenue were from the alcoholic spirit tax, fishery tax, market tax, gambling den tax, fruit orchard tax and the boat tax. Suai (); levied from the Phrai suai who paid the tax in form of local valuables instead of serving corvee labors. Gold, lacquer, saltpeter, teak and beeswax were extracted from the hinterland regions of Khorat Plateau and the Upper Chao Phraya Basin for Bangkok. These forests products were usually sold to foreign merchants to benefit the royal court. Reucha (); collected as fees from government procedures such as court hearings and other document procedures. Taxes were collected in forms of commodities or currency money. Main spending of the royal court went to the Biawat or the stipends of all administrative officials and the construction of palaces and temples and firearm purchases. In the early decades of Rattanakosin, the financial situation of the royal court was in strain. In 1796, Prince Maha Sura Singahanat of the Front Palace, who received 1,000 chang annually, informed King Rama I that his share was inadequate to be distributed as Biawat to his officials. King Rama I replied that the prince should invest more in the Royal Junks to earn money. King Rama I conducted his personal trade with Qing China through the Samphao Luang () or Royal Junks, in joint venture with Chinese merchants who provided the crew. Export demands on Siam had been mainly forest products such as agarwood and sappanwood. The royal court acquired valuable products from the hinterland and loaded them on the junks to be traded. Chinese merchants enhanced this process by taking the role as middlemen and shippers. Qing China had been the main trading partner of Siam since the late Ayutthaya period. In the early nineteenth century, Qing China requested to buy rice from Siam.