Anna Dalla Marta

Optically-assessed preformed flavonoids and susceptibility of grapevine to Plasmopara viticola under different light regimes

The role of flavonoids in the response of plants to Plasmopara viticola, the phytopathogen agent of downy mildew, was studied in the Vitis vinifera L. cultivar Sangiovese. Grapevines in the vineyard were exposed to two light regimes, 100% and 35% of full sunlight in order to induce differences in total leaf polyphenolic content. Epidermal leaf phenolic compounds were assessed optically, using the Dualex chlorophyll fluorescence-based portable leaf-clip. Dualex data were calibrated by means of HPLC analysis of extracts from the same measured leaves. Good correlations were obtained with total flavonoid contents, which consist mainly of quercetin 3-O-glucuronide. From the Dualex non-destructive measurements, we showed that full-sun exposed leaves contained 75% more flavonoids than shaded leaves. Inoculation of leaves with P. viticola sporangia resulted in a significantly lower infected leaf area in sun-lit leaves compared with shaded ones, as seen from subsequent analysis of the downy mildew severity. These results indicated an inverse relationship between preformed flavonoids and the susceptibility of grapevines to downy mildew. The rapid optical method for the non-destructive assessment of flavonoids presented here could be useful for large scale screening and predicting V. vinifera susceptibility to P. viticola.

Energy and Water Use Related to the Cultivation of Energy Crops: a Case Study in the Tuscany Region

The contribution of agrobiomasses, as a source of energy, to the reduction of greenhouse gas emissions was confirmed by several studies. Biomass from agriculture represents one of the larger and more diverse sources to exploit and in particular ethanol and diesel have the potential to be a sustainable replacement for fossil fuels, mainly for transport purposes. However, the cultivation of energy crops dedicated to the production of biofuels presents some potential problems, e.g., competitiveness with food crops, water needs, use of fertilizers, etc., and the economic, energy, and environmental convenience of such activity depends on accurate evaluations about the global efficiency of the production system. In this study, the processes related to the cultivation of energy crops were analyzed from an energy and water cost perspective. The crops studied, maize (Zea mais) and sunflower (Helianthus annuus), were identified for their different water requirements and cultivation management, which in turns induces different energy costs. A 50-year climatic series of meteorological data from 19 weather stations scattered in the Tuscany region was used to feed the crop model CropSyst for the simulation of crop production, water requirement, and cultivation techniques. Obtained results were analyzed to define the real costs of energy crop cultivation, depending on energy and water balances. In the energy crop cultivation, the only positive energy balance was obtained with the more efficient system of irrigation whereas all the other cases provided negative balances. Concerning water, the results demonstrated that more than 1.000 liters of water are required for producing 1 liter of bioethanol. As a consequence, the cultivation of energy crops in the reserved areas of the region will almost double the actual water requirement of the agricultural sector in Tuscany.

Solar radiation affects grapevine susceptibility to Plasmopara Viticola

Solar radiation plays an important role in the development of some fungal diseases due to its direct action on the microorganisms and also its indirect effect on the production of specific plant compounds. This experiment examined the effect of two light environments (100% and 35% of full strength) on the polyphenolic content of grapevine leaves and quantified their relation to resistance to downy mildew (Plasmopara viticola). Leaf epidermal polyphenolic contents were non-destructively measured during the growing season 2006 using the Dualex chlorophyll fluorescence-based portable leaf-clip. The experimental design consisted of six parcels of 30 vines and measurements were performed on the 12 central vines. The leaves were inoculated with a sporangia suspension containing 50,000 sporangia of P. viticola per mL and the disease severity was assessed after the appearance of symptoms. Leaves maintained at 100% sun had high polyphenolic content and significantly lower disease severity compared to leaves under shading nets. These results indicate an inverse relationship between produced polyphenolics and downy mildew severity.

Mediterranean climate patterns and wine quality in North and Central Italy

Results show that the year-to-year quality variation of wines produced in North and Central Italy depends on the large-scale climate variability, and that the wine quality improvement in the last four decades is partially due to an increase of temperature and to a decrease of precipitation in West and Central Mediterranean Europe (WME; CME). In addition, wine quality is positively correlated with air temperature throughout the entire active period of the grapevine, weakly negatively correlated with precipitation in spring, and well negatively correlated in summer and fall. The month-to-month composites of the NAO anomaly show that, in years of good quality wine, this anomaly is negative in late spring, oscillates around zero in summer, and is positive in early fall; while, in years of bad quality wine, it is positive in late spring and summer, and negative in early fall, i.e. its polarity has an opposite sign in spring and fall in good versus bad years. The composite seasonal maps show that good wines are produced when the spring jet stream over the Atlantic diverts most of the weather perturbations towards North Europe, still providing a sufficient amount of rainwater to CME; when summer warming induced by southerly winds is balanced by the cooling induced by westerly winds; and when a positive geopotential anomaly over WME shelters CME from fall Atlantic storms. Bad quality wines are produced when the jet stream favors the intrusion of the Atlantic weather perturbations into the Mediterranean. Results suggest that atmospheric pattern persistencies can be used as precursors for wine quality forecast.

The agroclimatic analysis at farm scale

Research was performed in Poggio Casciano Estate (Chianti area, central Italy) with the aim of defining a general approach to analyse the spatial variability of temperature at the microscale. Hourly data were collected from a network of 27 temperature stations covering an area of about 120 ha and determination coefficients (r2) between station pairs on the basis of different geo-topographical factors were calculated. The data were analysed in order to investigate trends describing the spatial distribution of temperature inside the study area. The results pointed out a strong effect of some topographical condition on the distribution of thermal patterns, in particular altitude and the distance from valley bottoms. The results are discussed in order to formulate a general approach for the characterisation of climatic conditions at small scale. Copyright

Impacts of the NAO on Mediterranean Crop Production

Meteorological conditions can influence the main biological processes responsible of plant growth and development affecting vegetative growing, setting and ripening of different plant organs, onset and duration of phenological stages and the final production, exerting a strong impact on agricultural activities. In particular, the study of the variability of timing and length of the plants growing season is gaining importance because plant phenology is a sensitive indicator of climate change and has large impacts on terrestrial ecosystems through changes in productivity and in the annual carbon and water cycles. For many years, starting from meteorological information, mathematical descriptions of these effects have been formulated in order to provide users (farmers, technicians, extension services, researchers, etc.) with operational tools for improving management and planning activities. Besides common meteorological information supplied by local or synoptic weather stations, the use of large-scale climatic variables has also been investigated in order to forecast agricultural yields and production quality in several regions of the world. In Europe, the North Atlantic Oscillation (NAO) seems to be responsible for a large component of climate variability, particularly influencing winter and, through climate interactions on plants, crop production quality and quantity characteristics. The use of large-scale meteorological information showed great potential, particularly for the development of crop production forecasting systems.

Weather and climate monitoring for food risk management

Food insecurity represents one of the main indicators of the poverty level of a country and can breed a strong dependence on foreign aid with a strong slowdown of the national economy. African arid and semi-arid areas are characterised by food precariousness and their agricultural activity is strongly dependent on the extreme climatic conditions that affect the available water supply. This situation has led to the need to develop new tools for the prediction and the management of crisis. The characterisation of climate and the identification of anomalies, the monitoring of weather conditions and their influence on crops, short and medium range weather forecasts and long-term climate predictions are among the most powerful tools to predict, in as short a time as possible, crises due to the absence or delay of rainfall season. Meteorological information can also be used as an input to agrometeorological models applied for crisis prevention or for its management during the growing season when the crops are already present. In this paper, a review of these tools is made and some operational products presented. Copyright

A methodological approach for assessing the impact of urban agriculture on water resources: a case study for community gardens in Rome (Italy)

ABSTRACT The paper proposes a methodology to assess water consumption in urban agriculture. Green and blue water footprints were calculated for five selected community gardens (CGs) in Rome (Italy) based on weather, crops, and yields. Then, the water requirement for all the CGs of the city, identified by means of a geodatabase, was estimated. For a cultivated area of 4.06 ha, an overall water requirement of 22,036 m3 (13,596 m3 green and 8,440 m3 blue) resulted from the assessment. Considering also the efficiency of the irrigation system, blue water consumption would reach 20,000 m3 in the worst scenario (furrow irrigation).

Effect of climate and of agricultural practice on the vegeto-productive response of ancient wheat varieties: preliminary results

Conservation agriculture (CA) can improve sustainable rice production. This work evaluated the effect of different CA practices on rice agronomic system. A four-year experiment (2013-2016) was carried out in Crescentino (VC), North-West Italy, comparing three tillage managements (sod dry seeding, sod wet seeding and ploughing), combined with three N fertilisation levels (0-110160 kg N ha) and two straw management (straw retained and removed). Yield and yield components were influenced by both tillage practices and N fertilisation, but not by straw management. Sod seeding reduced grain yield of about 16% with respect to ploughing, because of the lower panicle density and higher sterility. Rice responded to N fertilisation, but the higher sterility limited the positive effect at high N rates. Moreover, in sod seeding, high N supply increased Apparent Recovery (AR). Straw retention improved soil quality, increasing soil organic carbon concentration.

The role of soil organic matter on greenhouse gas emissions from different fertilizers

Conservation agriculture (CA) can improve sustainable rice production. This work evaluated the effect of different CA practices on rice agronomic system. A four-year experiment (2013-2016) was carried out in Crescentino (VC), North-West Italy, comparing three tillage managements (sod dry seeding, sod wet seeding and ploughing), combined with three N fertilisation levels (0-110160 kg N ha) and two straw management (straw retained and removed). Yield and yield components were influenced by both tillage practices and N fertilisation, but not by straw management. Sod seeding reduced grain yield of about 16% with respect to ploughing, because of the lower panicle density and higher sterility. Rice responded to N fertilisation, but the higher sterility limited the positive effect at high N rates. Moreover, in sod seeding, high N supply increased Apparent Recovery (AR). Straw retention improved soil quality, increasing soil organic carbon concentration.