Potato cultivation is quite demanding in inorganic nutrients and adequate fertilization is a key factor for maximizing yield and producing tubers of high quality. In the present study, a field experiment was carried out to evaluate the effect of various forms of fertilization on crop performance and the nutritional value and chemical composition of two potato varieties (cv. Spunta and cv. Kennebec). For this purpose, five different fertilizer treatments were applied namely: control (C), standard fertilizer (T1), standard fertilizer + zeolite (T2), manure (T3) and slow release nitrogen fertilizer (T4). According to the results, it was observed that slow release treatment (T4) achieved the highest yield for both varieties, while the control treatment presented significantly lower yield compared to the studied fertilization regimes. The dry matter of leaves and shoots was higher in T1 treatment for cv. Kennebec and in T2 and T4 treatments for cv. Spunta, whereas the control treatment presented the highest dry matter content in tubers for cv. Kennebec and T2 and T3 treatments for cv. Spunta. A significant effect of the fertilization regime was also observed on the nutritional value of tubers and more specifically the protein, ash and fat content was increased by treatments T1 and T4, while carbohydrate content was also increased by T3 and T4 treatments for both varieties. Similarly, the total sugars, organic acids, β-carotene and lycopene content was increased in T3 treatment for the Spunta variety, while the antioxidant capacity showed a varied response depending on the fertilizer regime and the tested variety. In conclusion, the fertilization regime has a significant effect not only on the tuber yield but also on the quality of the final product and should be considered as an effective tool to increase the added value of potato crop.

中文翻译：

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施肥制度对希腊中部种植马铃薯（Solanum tuberosum L.）作物性能和化学成分的影响

马铃薯的无机营养需求非常高，适当的施肥是最大化产量和生产优质块茎的关键因素。在本研究中，进行了田间试验，以评估各种施肥形式对两种马铃薯品种（cv。Spunta和cv。Kennebec）的作物性能以及营养价值和化学成分的影响。为此，使用了五种不同的肥料处理方法：对照（C），标准肥料（T1），标准肥料+沸石（T2），肥料（T3）和缓释氮肥（T4）。根据结果​​，观察到缓释处理（T4）两种品种均达到最高产量，而对照处理相比所研究的施肥方案则明显降低了产量。T1处理cv的叶片和芽的干物质较高。肯纳贝克（Kennebec）以及在T2和T4治疗中进行简历。Spunta，而对照处理在块茎中表现出最高的干物质含量。肯纳贝克和T2和T3的心血管治疗。蓬塔 还观察到施肥方式对块茎的营养价值具有显着影响，更具体地说，两种品种的T1，T4处理均增加了蛋白质，灰分和脂肪含量，而T3和T4处理也提高了碳水化合物的含量。同样地，在Spunta品种的T3处理中，总糖，有机酸，β-胡萝卜素和番茄红素的含量增加，而抗氧化能力根据肥料制度和试验品种表现出不同的响应。结论，