Dynamics of the production process of sweet potato cultivated in the sandy soil conditions in Romania

摘要

Sweet potato or bathe [ Ipomoea batatas (L.) Lam], a drought-tolerant plant, originates in Central America and now cultivated on large areas in China, India, Japan, Africa, the US, Mediterranean areas of Europe in a soil having moderate fertility. In Romania there are about 439,000 ha of sandy areas and due to more and more frequent changes of climate, it is necessary to find some species and varieties, which can withstand the thermohydric stress. In this respect, during the period 2015-2017, at D?buleni, located in southern Oltenia, Romania we have studied five sweet potato varieties of Korean origin, with different growing seasons, (Yulmi, Juhwangmi, Hayanmi, KSP 1 and KSC 1), in order to determine the plant's reaction to the color of the mulch used to protect the soil and the time of harvesting. The results showed that most of the genotypes had reached a maximum production potential at 120 days from the planting of the shoots in the field (24232.1-37746.1 kg / ha, in the variants with transparent mulch and 22327-38587.7 kg / ha, in the variants with smoky mulch). The exception is the Juhwangmi variety, which, being earlier, achieved the maximum yield when the harvest was carried out 110 days after planting, irrespective of the color of the mulch (47044,4-48285 kg / ha). Harvesting sweet potato varieties outside the optimal age of the plant maturity, results in the reduction of production and the depreciation of its quality, having negative repercussions in winter storage.