Assessing the Effects of Vineyard Soil Management on Downy and Powdery Mildew Development

Abstract

Advantages of vineyard cover crops include soil conservation, nutrient and water cycling, and a better growth–yield balance. They naturally promote agro-system biological multifunctionality, soil biocenosis, and biological pest control. However, for the role of cover crops on disease control, there is still a lack of information. We performed a systematic evaluation of the soil management effects on the development of two main pathogens: Plasmopara viticola and Erysiphe necator. Conventional soil tillage was compared to grass and legume cover crops during a three-season trial in the Nurra wine region (Sardinia, Italy). Disease and grapevine development were assessed in relation to the weather, leaf area growth, leaf nitrogen, canopy density, and favorable microclimatic conditions for each disease, to weight their importance on disease susceptibility in each treatment. Higher infection percentages were observed in plots subjected to soil tillage. Disease development was better understood in relation to leaf area, leaf nitrogen, and canopy density. The main role of weather conditions on downy mildew infections was ascertained, yet high canopy sunlight levels reduced disease spread under grass cover. For powdery mildew, leaf nitrogen had a crucial role in disease development under soil tillage, and canopy light and hygrothermal conditions had the most relevant function on disease development in cover-cropped vineyards.

Multiple Effects of Nitrogen Fertilization on Grape Vegetative Growth, Berry Quality and Pest Development in Mediterranean Vineyards

“…In this perspective, cultural practices may play a key role, as they impact the vineyard agroecosystem as a whole and deeply affect the fitness of pests and diseases. In fact, nitrogen fertilization and soil management practices that promoted N accumulation in the soil, such as tillage and legume cover crop, also promoted infections by powdery and downy mildew [26] and population growth of the vine mealybug [27,28]. In addition, removal of supernumerary leaves and secondary shoots in summer may concur to reduce VMB density by enhancing the foraging activity of parasitoids and aerating the canopy, thereby increasing the effectiveness of chemical applications [29].…”

UV light and adaptive divergence of leaf physiology, anatomy, and ultrastructure drive heat stress tolerance in genetically distant grapevines

“…The measurements were performed during flowering (BBCH 65), pea size (BBCH 73), cluster closure (BBCH 80), veraison (BBCH 83), and in 6 days of the year (DOY), from May to October 2018, on six adult leaves per treatment and variety with five reads in each leaf blade side. The measurements were repeated in the laboratory, and the leaf area of each replicate was estimated ( Fernandes de Oliveira and Nieddu, 2016a ; Fernandes de Oliveira et al., 2021 ). Furthermore, leaf mass per area (LMA) was estimated on 5-cm-diameter leaf blade discs, dried at 60°C for 48 h, and weighed.…”

Phenotyping for QTL identification: A case study of resistance to Plasmopara viticola and Erysiphe necator in grapevine

“…For instance, temperatures below 8°C (Moyer et al, 2010 ), nutrient deficiency (Keller et al, 2003 ), and drought (Heyman et al, 2021 ) reduce the development and susceptibility of grapevine organs to diseases, delaying epidemics (Moyer et al, 2016 ). In addition, cultural strategies (soil tillage and fertilization) and stimulated grapevine growth increase both leaf and berry susceptibility to pathogens (Fernandes de Oliveira et al, 2021 ).…”