Broad beans, also known as arhat beans, Hu beans and orchid beans; Panicum miliaceum. The flowering period is April-May and the fruiting period is May-June. It is cultivated all over China. Broad bean is suitable for spring sowing and is a deep-rooted crop; The whole growth period 1 10 ~ 120 days. It can withstand the low temperature of -4℃, but it is afraid of summer heat. The temperature requirement varies with the growth period. The suitable temperature for seed germination is 16 ~ 25℃, the lowest temperature is 3 ~ 4℃, and the highest temperature is 30 ~ 35℃. The temperature required in vegetative growth period is relatively low, the lowest temperature is 14 ~ 16℃, and the temperature required in flowering and fruiting period is 16 ~ 22℃. Under the low temperature of -4℃, the above-ground parts will suffer from freezing damage.