Zhenpeng Deng

Biochar and organic fertilizers are recommended for sustaining crop yield and sustainable agricultural development. However, the mechanisms of their combined application on the nutritional, flavor and eating quality and their optimal ratio remain unclear in sweet potatoes. Therefore, this field experiment employed four fertilization treatments: inorganic compound fertilizer (CF), organic fertilizer (OF), and biochar-based organic fertilizer containing 15% biochar (BOF15) or 30% biochar (BOF30). The results revealed that the OF, BOF15, and BOF30 treatments significantly ameliorated soil physical properties, elevated soil pH values and available nutrient contents compared with CF. They also increased sweet potato yield, regulated sucrose-metabolizing enzyme, and enhanced quality. Among them, the BOF15 treatment exhibited the most significant improvement. Compared with CF, BOF15 treatment increased the contents of starch, total soluble sugar, sucrose, and β-carotene by 23.16–31.82%. It also optimized texture by reducing hardness and chewiness while increasing springiness, elevated key volatile compounds (terpene and aldehyde), and received the highest sensory scores for mealiness, aroma, and sweetness. In conclusion, biochar combined with organic fertilizer synergistically improves soil properties and enhances sweet potato yield and quality, with BOF15 being the optimal treatment. This study provides support for optimizing fertilization strategies in high-quality sweet potato production.

To analyze the impact of intercropping, maize straw returning, plastic mulching, and different configurations on potato quality in southwest China, a three-factor split-plot field experiment was designed to investigate the effects of crop management practices on the starch physicochemical properties and textural properties for two potato cultivars (Mira and Huayu-5). Results indicated that intercropping, maize straw returning, and plastic mulching reduced tuber dry matter, total starch, and amylose content, thereby decreasing the hardness of steamed tubers. Plastic mulching and maize straw returning increased starch granule size, promoted thermal properties, improved pasting properties, and increased adhesiveness and cohesiveness. The potato/maize relay intercropping increased the thermal properties, pasting viscosities, adhesiveness, and cohesiveness, with stronger effects observed in Mira compared to Huayu-5. The combination of intercropping with plastic film mulching and straw returning reduces tuber hardness while enhancing tuber adhesiveness and cohesiveness.

Sweet potato virus disease (SPVD) is one of the main virus diseases in sweet potato [Ipomoea batatas (L.) Lam] that seriously affects the yield of sweet potato. Therefore, the establishment of a simple, rapid and effective method to detect SPVD is of great significance for the early warning and prevention of this disease. In this study, the experiment was carried out in two years to compare the grafting method and side grafting method for three sweet potato varieties, and the optimal grafting method was selected. After grafting with seedlings infected with SPVD, the symptomatic diagnosis and serological detection were performed in 86 host varieties, and the differences in SPVD resistance were determined by fluorescence quantitative PCR (qRT-PCR) and nitrocellulose membrane enzyme-linked immunosorbent assay (NCM-ELISA). The results showed that the survival rate of grafting by insertion method was significantly higher than that by side grafting method, and the disease resistance of different varieties to sweet potato virus disease was tested. The detection method established in this study can provide theoretical basis for identification and screening of resistant sweet potato varieties.