The party claimed the failure caused the prices of three main crops to drop.
The Democrat leader will also announce key failures of the government on the occasion of its first anniversary on Friday, a day before the administration is expected to hold an event to announce its achievements.
Chinnaworn Boonyakiart, the Democrat shadow agriculture minister, said the government of Prime Minister Yingluck Shinawatra caused the prices of rubber sheets, palm oil and fruit, and coconuts to fall during its first year in office.
The failure of the Yingluck government caused a drop in the price of rubber sheets from Bt140 per kilogram during the Abhisit government to Bt76 now, Chinnaworn said.