International Journal of Horticulture, 2025, Vol.15, No.2, 80-90 http://hortherbpublisher.com/index.php/ijh 84 reducing pest densities and increasing yields (Nboyine et al., 2018). Additionally, rain shelters have been demonstrated to significantly reduce disease severity and enhance profitability in regions with high rainfall (Du et al., 2015). 6.3 Disease-resistant varieties and genetic approaches The development and use of disease-resistant grapevine varieties are critical for sustainable viticulture. Traditional breeding and modern biotechnological methods, such as transgenesis, cisgenesis, and genome editing, have been employed to enhance resistance to major fungal and oomycete pathogens (Rashad et al., 2021; Pirrello et al., 2022; Wang et al., 2024). For instance, the application of silica nanoparticles has shown promise in reducing downy mildew severity by up to 81.5% and improving yield and berry quality (Rashad et al., 2021). Furthermore, beneficial bacteria and their secondary metabolites are being explored as biocontrol agents to reduce the reliance on chemical pesticides and enhance plant defenses (Compant et al., 2013). 7 Case Study: High Yield Strategies in A Specific Vineyard 7.1 Background of the vineyard The vineyard selected for this case study is located in the Berg River Valley region of South Africa, known for its favorable conditions for viticulture. The vineyard primarily cultivates the Dan-ben-Hannah/Ramsey table grape variety, which is well-suited to the local climate and soil conditions. The vineyard employs drip irrigation systems to optimize water use and ensure consistent moisture levels for the grapevines (Howell and Conradie, 2016). 7.2 Agronomic practices implemented Several agronomic practices were implemented to enhance yield and fruit quality in this vineyard. Three different fertigation strategies were compared: (i) application of fertilizers two weeks after bud break, fruit set, and post-harvest (LF), (ii) weekly applications from two weeks after bud break until ten weeks after harvest, except during berry ripening (WF), and (iii) daily fertigation pulses (DF). Each strategy aimed to optimize nutrient availability throughout the growing season (Howell and Conradie, 2016). The vineyard employed various canopy management techniques, including shoot thinning and defoliation at different growth stages. These practices aimed to balance vegetative growth and fruit production, thereby improving grape quality and yield (Silvestroni et al., 2016). The use of mulches, such as straw and living mulch, was implemented to control weeds, maintain soil moisture, and enhance soil quality. These mulches also contributed to higher organic matter and improved soil structure, which are beneficial for grapevine health and productivity (DeVetter et al., 2015). Partial rootzone drying (PRD) was used to manage vine vigor and water use efficiency. This technique involves drying part of the root system while maintaining moisture in the other part, which helps in reducing excessive vegetative growth and improving fruit quality without compromising yield. 7.3 Results and key takeaways The implementation of these agronomic practices yielded significant results. The daily fertigation pulses (DF) strategy resulted in higher nutrient accumulation in the grapevines, particularly nitrogen (N), phosphorus (P), and potassium (K) in the berry skins. This strategy also led to higher petiole P and leaf blade P concentrations compared to the other fertigation strategies (Howell and Conradie, 2016). The use of shoot thinning combined with preanthesis defoliation (St+Dpa) increased sugar concentrations in the grapes, enhancing fruit quality. However, this practice also reduced leaf area and yield by 33% compared to the control, indicating a trade-off between yield and quality (Silvestroni et al., 2016). The application of straw and living mulches effectively controlled weed populations and improved several indicators of soil quality, such as organic matter content, total organic carbon, and soil enzymatic activity. These improvements contributed to maintaining grapevine productivity and fruit quality (DeVetter et al., 2015). The partial rootzone drying (PRD) technique successfully reduced shoot growth and water use while maintaining crop yield and improving fruit quality. This method proved to be an effective tool for managing vine vigor and optimizing water use in the vineyard.
RkJQdWJsaXNoZXIy MjQ4ODYzNA==