The traditional feudal land ownership system meant that farmers had no incentive to invest in planting long-term tree crops on land they did not own, but in the late twentieth century kava and vanilla from larger plantations became the main agricultural exports, together with squash. The export of squash to Japan, beginning in 1987, once brought relief to Tonga's struggling economy, but local farmers became increasingly wary of the Japanese market due to price fluctuations, not to mention the huge financial risks involved.