Viticulture has adapted foliar applications of biostimulants as a tool to improve crop quality. Recently, nanotechnology has been incorporated as a strategy to reduce the loss of biostimulants and treat nutrient deficiencies. Therefore, the present study aimed to investigate the effect of foliar applications of amorphous calcium phosphate nanoparticles (ACP) doped with methyl jasmonate (ACP-MeJA) and urea (ACP-Ur), individually or together (ACP-MeJA+Ur), on the content of volatile compounds in 'Tempranillo' grapes, compared to the conventional application of MeJA and Ur, individually or in combination (MeJA+Ur).
Abstract Warm and semi-arid climates are characterized by rainfall scarcity, resulting in the frequent use of low-quality water for irrigation. This work was undertaken to study the effects of water stress and saline irrigation on yield and grape composition of Monastrell grapevines grafted onto 1103P rootstock. The experiment was carried out during three consecutive seasons in a commercial vineyard located in Jumilla (SE Spain) with a loamy-sandy soil. Rainfed vines were compared with five watering regimes including a Control, irrigated with standard water, and four treatments that combined two different schedules for irrigation initiation (pre- and post-veraison) with saline water obtained by adding two types of salts (sulphates and chlorides). Vines from treatments with more severe water stress (i.e., rainfed) showed lower yields and vegetative growth. Moreover, the Rainfed treatment clearly modified grape composition when compared with the Control treatment by increasing berry phenolic content. The application of saline water slightly affected vine performance and grape composition regardless of the type of salts added to the irrigation water. Indeed, the watering regime had a greater effect on yield, vegetative growth and grape composition than the use of different saline waters. Our results suggest that, in the mid-term (3 years), and with a vineyard soil with good drainage, the use of saline waters is not detrimental to vine performance, but does not improve grape composition. Further research is required to assess the long-term effects of saline water application, particularly in view of the important accumulation of chlorides and sodium in leaf tissues observed in vines watered with salty water at the last season of this experiment.
Viticulture is highly dependent on phytochemicals to maintain good vineyard health. However, to reduce their accumulation in the environment, green regulations are driving the development of eco-friendly strategies. In this respect, seaweeds have proven to be one of the marine resources with the highest potential as plant protective agents, representing an environmentally-friendly alternative approach for sustainable wine production. The current work follows an interdisciplinary framework to evaluate the capacity of Ulva ohnoi and Rugulopteryx okamurae seaweeds to induce defense mechanisms in grapevine plants. To our knowledge, this is the first study to evaluate Rugulopteryx okamurae as a biostimulator . This macroalgae is relevant since it is an invasive species on the Atlantic and Mediterranean coast causing incalculable economic and environmental burdens. Four extracts (UL1, UL2, RU1 and RU2 developed from Ulva and Rugulopteryx, respectively) were foliar applied to Tempranillo plants cultivated under greenhouse conditions. UL1 and RU2 stood out for their capacity to induce defense genes, such as a PR10, PAL, STS48 and GST1, mainly 24 hours after the first application. The increased expression level of these genes agreed with i) an increase in trans-piceid and trans-resveratrol content, mainly in the RU2 treated leaves, and, ii) an increase in jasmonic acid and decrease in salicylic acid. Moreover, an induction of the activity of the antioxidant enzymes was observed at the end of the experiment, with an increase in superoxide dismutase and catalase in the RU2-treated leaves in particular. Interestingly, while foliar fungal diversity was not influenced by the treatments, alga extract amendment modified fungal composition, RU2 application enriching the content of various groups known for their biocontrol activity. Overall, the results evidenced the capacity of Rugulopteryx okamurae for grapevine biostimulation, inducing the activation of several secondary metabolite pathways and promoting the abundance of beneficial microbiota involved in grapevine protection. While further studies are needed to unravel the bioactive compound(s) involved, including conducting field experiments etc., the current findings are the first steps towards the inclusion of Rugulopteryx okamurae in a circular scheme that would reduce its accumulation on the coast and benefit the viticulture sector at the same time.
Abstract In vineyards in Spain, tillage and semiarid Mediterranean climatic conditions accelerate organic matter loss from the soil. Cover crops are a conservation management practice that can provoke changes in soil quality which requires evaluation. Stratification ratios of soil properties such as soil organic C and labile C fractions have been proposed for the assessment of soil quality under different soil management systems. Our objective was to study the effect of different cover crop management on various soil parameters and their stratification ratios. We evaluated three different soil managements in a Typic Haploxerept from NE Spain: conventional tillage (CT); 5‐y continuous cover crop of resident vegetation (RV); and 4‐y continuous cover crop of Festuca longifolia Thuill., followed by 1‐y Bromus catharticus L. after resowing (BV). We monitored soil organic C, particulate organic C, water soluble C, potentially mineralizable N, microbial biomass C, β‐glucosidase and urease enzymatic activities, and water stable aggregates at 0–2.5, 2.5–5, 5–15, 15–25, and 25–45 cm soil depths. We calculated soil depth stratification ratios of those soil properties. Resident cover crop increased microbiological properties, labile C fractions, and aggregation with respect to conventional tillage at 0–2.5 and 2.5–5 cm soil depths. However, for Bromus cover crop the same soil properties were lower than for the resident cover crop at 0–2.5 cm depth. Stratification ratios of β‐glucosidase and urease enzymatic activities, and particulate organic C showed a higher sensitivity than other soil properties; therefore, they would be the best indicators for soil quality assessment in semiarid Mediterranean vineyards.
Little attention has been given to the utilization of permanent cover crops in vineyard agroecosystems in semi-arid Mediterranean climatic conditions to increase soil organic carbon or its effects on N availability. We evaluated the effect of permanent cover crops with resident vegetation on labile organic matter fractions and inorganic N availability with respect to conventional tillage in a semi-arid vineyard. The field experiment was conducted on Typic Haploxerept soil, located in La Rioja area (Central River Ebro Valley). Soil samples were collected during June 2009, 5 years after covers crops were established. Soil organic carbon (SOC), water-soluble carbon (WSC), potentially mineralizable nitrogen (PMN), nitrate (N-NO3 −) and ammonium (N-NH4 +) were measured. At soil depths of 0–2.5 and 2.5–5 cm the cover crops increased SOC, WSC and PMN. So the results indicated a soil quality improvement. The cover crop treatment reduced soil N-NO3 − and increased the WSC to inorganic N ratio at 0–45 cm depth. PMN and WSC increments suggest a more active microbial biomass that could promote the immobilization and recycling of N-NO3 −, and therefore might partially explain the reduction in N-NO3 − pools under cover crops.
The outlook for climate change foresees major impacts on vineyards worldwide, shifting pathogens distribution and dynamics demanding more intense plant protection measures in certain regions, increasing viticulture's dependence on phytochemicals and pesticides. However, the European Commission is applying restrictions on their use, encouraging the development of more sustainable strategies efficient for disease control. Seaweeds represent an ecological alternative for a more sustainable production. Previous studies have shown that algae extracts contain compounds capable of reducing the abundance of plant fungal pathogens. Despite it, little is known about the molecular mechanism underlying this response. SEAWINES project is evaluating the efficacy of the foliar application of Ulva ohnoi and Rugulopteryx okamurae extracts to control powdery and downy mildew, in addition to testing their effect on grape and wine quality. To our knowledge, this is the first study evaluating R. okamurae biostimulant capacity and fungicidal effect in viticulture. This macroalgae is relevant since it is an invasive species in our coasts, causing incalculable economic and environmental burdens. We aim to 1- Reduce the usage of chemicals in grapevines; 2- Reduce fungal diseases in viticulture; 3- Valorize polysaccharides from seaweeds; 4- Increase the added-value to wines (ecological and quality); and 5- Provide an alternative use to seaweed biomass, contributing to bio-circular economy and reducing its accumulation in our coasts.