Biodegradable liquid mulch film (LF), which can be degraded naturally without harming the environment, is a new type of covering material that provides an environmentally friendly alternative to plastic mulch film (PF). In this study, the effects of LF and PF (ploughing (CK) used as a control) on the soil and fruit quality of Hutai-8 were evaluated through an experiment, and several soil physicochemical properties and indicators of fruit quality were measured. In-row mulching significantly increased the content of total potassium, available phosphorus, and available potassium in the topsoil (0–20 cm), the ripeness of the grape berries, and the content of phenolics in the skin. The effects were consistent between the two years. The effect of LF was more pronounced in the same year, indicating that LF is an effective alternative to PF. Therefore, LF can be used as an environmentally friendly substitute for PF to improve soil and fruit quality and incorporated into cultivation management plans. Correlation analysis revealed that the content of reducing sugars, flavonoids, total phenols, flavan-3-ols, and anthocyanins, as well as fruit ripeness, increased as the content of total potassium, available phosphorus, and available potassium in the soil increased.

In vineyard mulching research, using biodegradable liquid mulch represents a novel and environmentally conscious approach to mulching. In comparison, grapevine branch return has been identified as the most effective mulching method. The effects of in-row mulching with two materials, biodegradable liquid film (BLF) and grapevine branches (GBM), on soil properties and microbial communities in the vineyard were assessed using a one-way horizontal block test with tillage as a control. The results indicated that the application of mulching resulted in a reduction in soil bulk weight; an increase in soil moisture; an enhancement in soil organic matter; and a notable elevation in soil nutrients content compared to the control treatment. Both mulching techniques increased the abundance and diversity of soil microorganisms, strongly correlated with soil physicochemical properties. The correlation analysis demonstrated that total organic carbon (TOC); total nitrogen (TN); total potassium (TK); nitrate nitrogen (NN); and available phosphorus (AP) had the most significant impact on shaping the microbial community, exhibiting a positive correlation with microbial diversity. Additionally, soil nutrients were identified to exert a more pronounced influence on the composition of the bacterial community.

Biodegradable liquid film (BLF) improves soil structure and increases plant freezing tolerance after spraying on the surface of soil and plant. In this study, the effects of BLF on grape composition and volatile compounds in Cabernet sauvignon (Vitis vinifera L.) grapes were determined by spraying BLF during the dormant periods over three years. The aim of the study was to evaluate the potential impact of BLF as an overwintering protection measure on grape fruit quality. In 2020 and 2021, BLF spraying increased reducing sugar content and 100-berry weight, decreased titratable acid content, and improved the maturity factor. Compared with the vines not sprayed with BLF, the content of total phenols and total anthocyanins in grape skins showed an increase over the three-year period, with the largest increases of 31.92% and 48.38%, respectively, and the content of total tannins and total flavan-3-ols increased in 2020 and 2021. BLF treatment also increased the total phenolic content in seeds for all three years, reaching a significant level in 2019, 16.38% higher than control treatment (CK). HPLC analysis showed that BLF treatment affected the content and composition of monomeric anthocyanins in grape skins, especially in 2021, BLF treatment significantly increased the content of nine monomeric anthocyanins, and the proportion of acetylated and coumaroylated anthocyanins. However, GC-MS analysis indicated that BLF had little effect on volatile compounds. These results suggest that BLF can be used as an overwintering protection measure in cold regions to promote the accumulation of sugars and polyphenolics, thereby improving overall grape quality.

Downy mildew caused by Plasmopara viticola is an important disease in grape production, particularly in the highly susceptible, widely cultivated Vitis vinifera L. Breeding for disease resistance is an effective solution, and V. vinifera intraspecific crosses can yield progeny with both disease resistance and high quality. To assess the potential of intraspecific recurrent selection in V. vinifera (IRSV) in improving grapevine resistance to downy mildew and to analyze the pattern of disease resistance inheritance, the disease-resistant variety Ecolly was selected as one of the parents and crossed with Cabernet Sauvignon, Marselan, and Dunkelfelder, respectively, creating three reciprocal combinations, resulting in 1657 hybrid F1 progenies. The primary results are as follows: (1) significant differences in disease resistance among grape varieties and, significant differences in disease resistance between different vintages of the same variety were found; (2) the leaf downy mildew resistance levels of F1 progeny of different hybrid combinations conformed to a skewed normal distribution and showed some maternal dominance; (3) the degree of leaf bulbous elevation was negatively correlated with the level of leaf downy mildew resistance, and the correlation coefficient with the level of field resistance was higher; (4) five progenies with higher levels of both field and in vitro disease resistance were obtained. Intraspecific hybridization can improve the disease resistance of offspring through super-parent genetic effects, and Ecolly can be used as breeding material for recurrent hybridization to obtain highly resistant varieties.

Low temperatures are among the most important abiotic stresses, severely affecting vine growth and development. In order to overwinter safely, grape growers pay high labor costs, which are unsustainable in modern agriculture. Biodegradable liquid film (BLF) is an environmentally friendly material that assists grapevines to withstand the cold. In this experiment, Cabernet Sauvignon from Junding Winery was used as material for field trials. The regulatory effect of BLF on the cold resistance of grapevines was analyzed, and its mechanism of action was explored using metabolomics. The results showed that BLF significantly increased the activity of superoxide dismutase, the content of proline and ascorbic acid, reducing sugar, sucrose, and soluble sugar, and also decreased the content of malondialdehyde. In addition, BLF significantly increased the activity of invertase and decreased the activity of pectinase and phosphofructokinase. Metabolomics data showed that BLF improved cold resistance in grapevines by affecting lipids, flavonoids, amino acids, and nucleotide metabolic pathways.