Since their use as pig feed still requires that farmers grow sweet potatoes, according to statistics of the agriculture department of the Taiwan provincial government, in 1968 the area under sweet potato cultivation reached its peak--about 240,000 hectares. Production was about 3,720,000 metric tons.
據台灣省農林廳調查，民國卅四年到六十年之間，甘薯種植面積一直保持在廿三萬公頃左右。民國五十七年時，甘薯種植面積曾達到最高點，約廿四萬公頃，當年產量亦高達三百七十二萬公噸。