This study addresses the low yield and fertilizer utilization efficiency of potatoes in the arid region of Xinjiang, Northwest China. The effect of a novel, fulvic acid-based specialized fertilizer for drip application on potato growth, development, yield, and fertilizer efficiency is investigated. The aim is to identify a suitable fertilizer formula for potato cultivation in Xinjiang and promote its demonstration and application, providing a theoretical basis for improving fertilizer efficiency and achieving stable, high yields in the region. The experiment was conducted with potato variety ‘Xisen 6’ using a field trial design, which included five treatments: no fertilizer (CK), conventional fertilizer (CF: N-P-K = 258-245-338 kg·ha⁻¹), formulated fertilizer 1 (F1: 120 g·L⁻¹ fulvic acid, N-P-K = 110-100-120 g·L⁻¹), formulated fertilizer 2 (F2: 60 g·L⁻¹ fulvic acid, N-P-K = 130-120-150 g·L⁻¹), and formulated fertilizer 3 (F3: 30 g·L⁻¹ fulvic acid, N-P-K = 170-150-130 g·L⁻¹). Agronomic traits, gas exchange parameters of leaves during the tuber expansion stage, and yield components at harvest were measured, along with the fertilizer use efficiency for each treatment. Results show that F1, F2, and F3 improved the potato plant height, stem diameter, aboveground dry weight, SPAD value, stomatal conductance (Gs), and yield. Among these, F2 significantly enhanced plant height, stem diameter, aboveground dry weight, and the accumulation of relative chlorophyll content (SPAD value) during the tuber expansion stage, increased photosynthesis, and further improved yield and fertilizer efficiency, resulting in a yield increase of 121.29% and 34.6% compared to CK and CF, respectively. Therefore, formula fertilizer F2 is identified as the optimal fertilization strategy for potato cultivation in Xinjiang. Its application has been further extended in demonstration trials. Field demonstration results show that F2 significantly increased potato yield, with a 14.79% yield increase compared to CK, proving its effectiveness in replacing conventional fertilizers and enhancing production.

Early blight, caused by the pathogen Alternaria solani, is a major fungal disease impacting potato production globally, with reported yield losses of up to 40% in susceptible varieties. As one of the most common diseases affecting potatoes, its incidence has been steadily increasing year after year. This study aimed to elucidate the molecular mechanisms underlying resistance to early blight by comparing gene expression profiles in resistant (B1) and susceptible (D30) potato seedlings. Transcriptome sequencing was conducted at three time points post-infection (3, 7, and 10 dpi) to identify differentially expressed genes (DEGs). Weighted Gene Co-expression Network Analysis (WGCNA) and pathway enrichment analyses were performed to explore resistance-associated pathways and hub genes. Over 11,537 DEGs were identified, with the highest number observed at 10 dpi. Genes such as LOC102603761 and LOC102573998 were significantly differentially expressed across multiple comparisons. In the resistant B1 variety, upregulated genes were enriched in plant–pathogen interaction, MAPK signaling, hormonal signaling, and secondary metabolite biosynthesis pathways, particularly flavonoid biosynthesis, which likely contributes to biochemical defense against A. solani. WGCNA identified 24 distinct modules, with hub transcription factors (e.g., WRKY33, MYB, and NAC) as key regulators of resistance. These findings highlight critical molecular pathways and candidate genes involved in early blight resistance, providing a foundation for further functional studies and breeding strategies to enhance potato resilience.

Intercropping systems are beneficial for resource utilization; however, the spatial proximity of companion species leads to competition for shared resources, particularly light. A walnut–potato intercropping model was established to understand the photosynthetic and physiological mechanisms underlying yield and marketability responses. Three intercropping treatments were established based on the number of potato ridges between walnut tree rows: B1 (three ridges), B2 (five ridges), and B3 (seven ridges). All intercropping and monoculture (CK) plots used an identical double-row planting pattern per ridge. Results showed that ridge density induced significant physiological changes and yield impacts. Compared to CK, B3 significantly reduced soluble protein content, net photosynthesis (Pn), and antioxidant enzyme activities (SOD, CAT), while B1 and B2 showed intermediate, non-significant reductions. Peroxidase (POD) activity increased progressively with ridge number (B3 > B2 > B1 > CK), indicating dose-dependent shade stress. Intercellular CO₂ concentration (Ci) was significantly elevated under all intercropping treatments, suggesting a predominantly non-stomatal, biochemical limitation on photosynthesis rather than water stress. Yield was highest in CK, followed by B1 and B2—which were statistically comparable to CK—while B3 yielded the least due to severe shading. Marketability declined sharply in B3, with fewer than half of tubers reaching commercial grade. Multivariate analysis showed distinct clustering of yield-associated variables (Pn, protein, marketability) separate from shade-stress indicators (POD, Ci) across treatments. These findings provide practical and scientific evidence to optimize walnut–potato intercropping configurations under the arid conditions.