Health-beneficial and cost-effective cultivation of the potato cv. Palace following sustainable production practices

Potatoes are a high-yielding crop with many nutritional benefits, such as carbohydrates, vitamins, antioxidants, and polyphenols. However, the cultivation method and environmental conditions affect their yield and nutritional content. The aim of the present study was to evaluate the effects of different rates of organic GuanoBoost™ (200, 400, 600, and 800 kg/ha GB) and conventional NPK fertilizer (2:3:4) as comparative nutritive methods and different locations (Nobadula, Bhala, Sakhikamva, Drayini, and UFH) on the yield and chemical composition of the potato cultivar Palace. The experimental design used in this study is a randomized complete block design, with four replicates. Yield parameters were weight and the number of tubers per plant. Vitamin C content was determined using the HPLC method, the antioxidant capacity was determined using both the FRAP and ABTS methods, polyphenols were determined using the Folin method, and moisture content was also determined. All experiments were performed in triplicate, and the results shown in the present paper represent the mean values obtained from the investigation. Findings revealed that across the five locations, the 600-kg/ha treatment was generally higher in weight and the number of tubers per plant than the NPK fertilizer, although in one location (Nobadula), the highest weight and the number of tubers per plant (1.34 kg and 12.5) were recorded, respectively. The study also found that the treatments had no significant impact on vitamin C content; however, location significantly influenced vitamin C content, with UFH having the highest (147.48 μg/g FW) and Drayini having the lowest (64.01 μg/g FW). The antioxidant capacity was significantly influenced by weather conditions, with high precipitation locations having the highest (Nobadula and Bhala) antioxidant capacity. The treatments and location also had significant effects on the chemical composition of potato tubers. Nobadula had the highest polyphenol content [300 kg/ha NPK (control)], while Drayini had the lowest (74.98%). It was also observed that the GB 600-kg/ha treatment was significantly higher in all the chemical compositions tested. The study concluded that organic cultivation using GuanoBoost™ fertilizer at a rate of 600 kg/ha has the potential to replace mineral conventional fertilizer, and humid climatic conditions favor the chemical composition of potato tubers.