地瓜(Pachyrrhizus erosus Urban.)又称豆薯或凉薯,它既可作蔬菜,又可作水果。在我国黄河以南各省均有栽培。由于地瓜起源于热带地区,属于短日照作物。在长江流域及其以北地区自然栽培条件下,要到八九月才能开花。开花后,需在日平均温度20℃ Sweet potato (Pachyrrhizus erosus Urban.) Also known as the bean or sweet potatoes, both as a vegetable, but also for fruit. In our province south of the Yellow River have cultivated. Since sweet potatoes originated in the tropics, are short-day crops. It is not until August or September that flowers will bloom under the natural cultivation of the Yangtze River and its northern region. After flowering, the daily average temperature needs to be 20 ℃