An Overview of the Latest Distribution of Pea Producing Areas
Peas are also known as green beans, snow peas, xiaohan beans, Huai beans, hemp beans, green small beans, liu beans, etc. They belong to long-day cool-season legumes and originated several thousand years ago in western Asia, the Mediterranean region, Ethiopia, and western Asia Minor, all of the Transcaucasus; Iran and Turkmenistan are their secondary centers of origin. China is the world's second-largest pea producer after Canada. Let's take a look at the distribution of pea producing areas below!
The Place of Origin of Peas
Vavilov of the Soviet Union believed that the centers of origin of peas were Ethiopia, the Mediterranean and Central Asia, with the Near East as a secondary center of evolution, while others believe they originated from southern Caucasia to Iran. Peas were first introduced eastward from their place of origin to northern India, then through Central Asia to China, introduced to Japan in the 16th century, and brought to the United States after the discovery of the New World.
In Central Asia, the Near East and northern Africa, the wild species Pisum elatius of the genus Pisum is also distributed. This species can be crossbred with currently cultivated peas and is fertile, and may be the primitive type of modern peas. Peas are now the world's fourth-largest legume crop.
The Distribution of Pea Producing Areas
1. Domestic producing areas: In China, peas are mainly distributed in the central and northeastern regions, with major producing areas in Sichuan, Henan, Hubei, Jiangsu, Qinghai, Jiangxi and several other provinces and regions.
2. Foreign producing areas: The foreign producing areas of peas mainly include western Asia, the Mediterranean region, Ethiopia, western Asia Minor and other regions.
The Producing Environment of Peas
1. Peas are long-day plants that prefer a cool, moist climate, are cold-tolerant and not heat-tolerant. Seedlings can withstand low temperatures of 5°C. The suitable temperature during the growing period is 12-16°C, and the suitable temperature during the pod-setting period is 15-20°C. Above 25°C, the fertilization rate is low, few pods are set, and yields are low. The growth period of most varieties is shorter in the north than in the south. When southern varieties are moved north, they flower and set pods earlier; this is because spring sowing in the north shortens the seedling period that would otherwise be spent overwintering in the south. Therefore, in the north, the growth period of peas is 65-75 days for early-maturing varieties, 75-100 days for mid-maturing varieties, and 100-185 days for late-maturing varieties.
2. Peas are not strict about soil requirements and can be planted in well-drained sandy loam or newly reclaimed land. A loose, neutral (pH 6.0-7.0) soil with relatively high organic matter content is preferable, as it is favorable for emergence and the development of rhizobia. When soil acidity is below pH 5.5, diseases are prone to occur and the pod-setting rate decreases, so lime should be added to improve the soil.
3. Peas have deep root systems and are slightly drought-tolerant but not moisture-tolerant. Poor drainage at sowing or during the seedling stage can easily cause root rot. Drought during the flowering period leads to poor fertilization and easily results in empty pods or shriveled pods.