Fenologia e efeito da desfolha parcial na produção extemporânea de efeito da desfolha parcial na produção extemporânea da videira, cultivar Cabernet Franc (Vitis vinifera L.), na região de São Roque - SP

Pós-graduação em Agronomia (Horticultura) - FCA

METHIOCARB, A CHEMICAL BIRD REPELLENT: A REVIEW OF ITS EFFECTIVENESS ON CROPS

Since 1964, when the effectiveness of methiocarb for preventing pheasants (Phasianus colchicus) from damaging sprouting corn was proven in South Dakota, an aggressive program has been carried out by personnel of the Denver Wildlife Research Center and many cooperators to develop methiocarb as a broad spectrum avian repellent. The successful use of methiocarb for preventing damage caused by several species of birds to sprouting corn in several states and to sprouting soybeans in South America is reviewed. Recent results obtained from spraying methiocarb on ripening rice in California, ripening sorghum in Colorado and Oklahoma, cherries in Michigan, and grapes in New Hampshire are summarized.

Fenologia e efeito da desfolha parcial na produção extemporânea de efeito da desfolha parcial na produção extemporânea da videira, cultivar Cabernet Franc (Vitis vinifera L.), na região de São Roque - SP

Pós-graduação em Agronomia (Horticultura) - FCA

Dose-dependent effect of Resveratrol on bladder cancer cells: Chemoprevention and oxidative stress

Background: Over 6 million people die annually in the world because of cancer. Several groups are focused on studying cancer chemoprevention approaches. Resveratrol, a polyphenol, at high dosages, has been reported as antitumor and chemopreventive. However, it has a dose-dependent effect on cell death, even on some cancer cells. Objectives: Our aim was to investigate this dose-dependent effect on human bladder carcinoma ECV304 cells during oxidative stress condition. Methods: For this purpose. ECV304 cells incubated with different Resveratrol concentrations were analyzed as for their metabolic rate, membrane permeability, DNA fragmentation, anti/proapoptotic protein levels and phosphatidylserine exposure after oxidative stress. Results: Resveratrol induced cell death at high concentrations (>20 mu M), but not at low ones (0.1-20 mu M). Pretreatment with 2.5 mu M protected the cells from oxidative damage, whereas 50 mu M intensified the cell death and significantly increased Bad/Bcl-2 ratio (proapoptotic/antiapoptotic proteins). Resveratrol was able to modulate NO and PGE(2) secretion and performed an anti-adhesion activity of neutrophils on PMA-activated ECV304 cells. Conclusions: Resveratrol at high doses induces cell death of ECV304 cells whereas low doses induce protection. Modulation of Bcl-2 protein induced by Resveratrol could be mediating this effect. This information about the role of Resveratrol on cancer alerts us about its dose-dependent effects and could lead the design of future chemoprevention strategies. Published by Elsevier Ireland Ltd.

Anti-Atherogenic Effects of a Phenol-Rich Fraction from Brazilian Red Wine (Vitis labrusca L.) in Hypercholesterolemic Low-Density Lipoprotein Receptor Knockout Mice

Moderate wine intake (i.e., 1-2 glasses of wine a day) is associated with a reduced risk of morbidity and mortality from cardiovascular disease. The aim of this study was to evaluate the anti-atherosclerotic effects of a nonalcoholic ethyl acetate fraction (EAF) from a South Brazilian red wine obtained from Vitis labrusca grapes. Experiments were carried out on low-density lipoprotein (LDL) receptor knockout (LDLr-/-) mice, which were subjected to a hypercholesterolemic diet and treated with doses of EAF (3, 10, and 30 mg/kg) for 12 weeks. At the end of the treatment, the level of plasma lipids, the vascular reactivity, and the atherosclerotic lesions were evaluated. Our results demonstrated that the treatment with EAF at 3 mg/kg significantly decreased total cholesterol, triglycerides, and LDL plus very low-density lipoprotein levels compared with control hypercholesterolemic mice. The treatment of mice with EAF at 3 mg/kg also preserved the vasodilatation induced by acetylcholine on isolated thoracic aorta from hypercholesterolemic LDLr-/- mice. This result is in agreement with the degree of lipid deposit on arteries. Taken together, the results show for the first time that the lowest concentration of an EAF obtained from a red wine produced in southern Brazil significantly reduced the progression of atherosclerosis in mice.

INHIBITION OF OVIPOSITION BY NEEM EXTRACT: A BEHAVIORAL PERSPECTIVE FOR THE CONTROL OF THE MEDITERRANEAN FRUIT FLY (DIPTERA: TEPHRITIDAE)

The behavioral inhibitory effect of methanol extracts from neem leaves (Azadirachta indica A. Juss) at different concentrations (0, 10,000, 18,000, 32,000 and 56,000 ppm) was evaluated using naive and experienced medflies (Ceratitis capitata (Wied.)) ovipositing on the fruits of grape cv. 'Italia'. The grapes were immersed in the specific treatments and were exposed for 24 h to 3 pairs of female and male medflies, both nave and experienced, in a choice test. At concentrations >= 18,000 ppm, the extract that was applied to the grapes inhibited oviposition. The previous experience with treated grapes did not affect the response of the medflies. This study is the first step toward the application of the behavior control of the medflies as a tool in grape vineyards. The potential for using oviposition inhibitory in behavioral control of C. capitata are discussed.

Characterization of red wines from South America based on sensory properties and antioxidant activity

BACKGROUND: It is widely accepted that red wines constitute one of the most important sources of dietary polyphenolic antioxidants. However, it is still not known how some variables such as variety, vintage, country of origin, and retail price are associated with the antioxidant activity and sensory profile of South American red wines. In this regard, 80 samples produced in Brazil, Chile and Argentina were assessed in relation to their sensory properties, color and in vitro antioxidant activity, and results were subjected to multivariate statistical techniques. RESULTS: Samples were grouped in clusters, characterized by high, intermediate and low in vitro antioxidant activity, sensory properties and prices. It was possible to observe that wines with high antioxidant activity were associated to high retail prices and overall perception of sensory quality. CONCLUSION: South American wines produced from Vitis vinifera such as Syrah, Malbec and Cabernet Sauvignon had higher in vitro antioxidant activity and also higher sensory quality than wines produced from Vitis labrusca. This result was independent of vintage (2002-2010), corroborating the idea that the same grape varietal, even when produced in different years, displays similar sensory characteristics and antioxidant activity. (C) 2011 Society of Chemical Industry

'Syrah' vine on different rootstocks in winter cycle in the south of Minas Gerais State, Brazil

The objective of this work was to evaluate rootstock influence on agronomical, ecophysiological and qualitative characteristics of 'Syrah' vines managed by double pruning. Grapevines were grafted onto 'SO4', '110 Richter' and '1103 Paulsen' rootstocks and trained in vertical shoot position, with no irrigation. Ecophysiological characteristics, yield and composition of ripe grapes were evaluated in three crop seasons (2007, 2008 and 2010). Rootstocks did not affect pre-dawn water potential, with values close to -0.2 MPa, indicating that there was no soil water deficit at the end of ripening (June). There was also no significant effect of rootstocks on yield. The rootstock '1103 Paulsen' induced lower vegetative growth, lower photosynthetic rate and the best results for berry maturation for crop seasons with lower amount of rainfall. The rootstocks '110 Richter' and 'SO4' showed higher vigor under the meteorological conditions of 2010 and the greatest photosynthetic rates in the same period. Meteorological conditions significantly affected technological and phenolic ripeness, with best results observed in drought years. The '1103 Paulsen' rootstock provides better balance between vigor and yield, increasing grape quality.

Studio genetico ed epidemiologico su Erysiphe necator agente eziologico dell'Oidio della vite

The objective was to analyse population structure and to determine genetic diversity of Erysiphe necator (syn. Uncinula necator) populations obtained from some vineyards located in the South-East Po valley (Italy). Powdery mildew is one of the most important fungal diseases of grapes (Vitis vinifera L.) throughout the world. The causal agent is the haploid, heterothallic ascomycete E. necator. It is an obligate biotrophic fungus and it can be found only on green organs of plants belonging to the family Vitaceae. For this pathogen, two sympatric populations (groups A and B) have been described in Europe and Australia. The two genetic groups differ at multiple genetic loci and previous studies reported a lack of interfertility among isolates of the two groups. There are now several well documented examples of plant pathogen species, such as Leptosphaeria maculans, Gaeumannomyces graminis var. tritici, Botrytis cinerea and Erysiphe syringae, which are indeed composed of genetically differentiated clades, that have led to the description of new groups or even new species. Several studies have suggested that genetic E. necator group A and B correlated with ecological features of the pathogen; some researchers proposed that group A isolates over-winter as resting mycelium within dormant buds, and in spring originate infected shoots, known as Flag shoots, while group B isolates would survive as ascospores in overwintering cleistothecia. However, the association between genetic groups and mode of over-wintering has been challenged by recent studies reporting that flag-shoot may be originated indifferently by group A or group B isolate. Previous studies observed a strong association between the levels of disease severity at the end of the growing season and the initial compositions of E. necator populations in commercial vineyards. The frequencies of E. necator genetic groups vary considerably among vineyards, and the two groups may coexist in the same vineyard. This finding suggests that we need more information on the genetics and epidemiology of E. necator for optimize the crop management In this study we monitored E. necator populations in different vineyards in Emilia – Romagna region (Italy), where the pathogen overwinters both as flagshoots and as cleistothecia. During the grape growing season, symptomatic leaves were sampled early in the growing season and both leaves and berries later during the epidemic growth of the disease. From each sample, single-conidial isolate was obtained. Each isolates was grown on V. vinifera leaf cv. Primitivo and after harvesting the mycelium, the DNA was purified and used as template for PCR amplification with SCAR primers (Sequences Characterised Amplified Region ), -tubulin, IGS sequences and Microsatellite markers (SSR). Amplified DNA from b-tubulin and IGS loci was digested with AciI and XhoI restriction enzymes, respectively, to show single-nucleotide polymorphisms specific for the two genetic groups. The results obtained indicated that SCAR primers are not useful to study the epidemiology. of E. necator conversely the b-tubulin IGS sequences and SSR. Summarize the results obtained with b-tubulin, IGS sequences, in treated vineyards we have found individuals of group B along all grape growing season, whereas in the untreated vineyard individuals of the two genetic groups A and B coexisted throughout the season, with no significant change of their frequency. DNA amplified from ascospores of single cleistothecia showed the presence of markers diagnostic for either groups A and B and were seldom observed also the coexistence of both groups within a claistothecium. These results indicate that individuals of the two groups mated in nature and were able to produced ascospores. With SSR we showed the possibility of recombination between A and B groups in field isolates. During winter, cleistothecia were collected repeatedly in the same vineyards sampling leaves fallen on ground, exfoliating bark from trunks, and from soil. From each substrate, was assess the percentage of cleistothecia containing viable ascospores. Our results confirmed that cleisthotecia contained viable ascospores, therefore they have the potential to be an additional and important source of primary inoculum in Emilia-Romagna vineyards.

Functional and molecular characterization of ethylene responsive factor genes involved in grape ripening

Grape berry is considered a non climacteric fruit, but there are some evidences that ethylene plays a role in the control of berry ripening. This PhD thesis aimed to give insights in the role of ethylene and ethylene-related genes in the regulation of grape berry ripening. During this study a small increase in ethylene concentration one week before véraison has been measured in Vitis vinifera L. ‘Pinot Noir’ grapes confirming previous findings in ‘Cabernet Sauvignon’. In addition, ethylene-related genes have been identified in the grapevine genome sequence. Similarly to other species, biosynthesis and ethylene receptor genes are present in grapevine as multi-gene families and their expression appeared tissue or developmental specific. All the other elements of the ethylene signal transduction cascade were also identified in the grape genome. Among them, there were ethylene response factors (ERF) which modulate the transcription of many effector genes in response to ethylene. In this study seven grapevine ERFs have been characterized and they showed tissue and berry development specific expression profiles. Two sequences, VvERF045 and VvERF063, seemed likely involved in berry ripening control due to their expression profiles and their sequence annotation. VvERF045 was induced before véraison and was specific of the ripe berry, by sequence similarity it was likely a transcription activator. VvERF063 displayed high sequence similarity to repressors of transcription and its expression, very high in green berries, was lowest at véraison and during ripening. To functionally characterize VvERF045 and VvERF063, a stable transformation strategy was chosen. Both sequences were cloned in vectors for over-expression and silencing and transferred in grape by Agrobacterium-mediated or biolistic-mediated gene transfer. In vitro, transgenic VvERF045 over-expressing plants displayed an epinastic phenotype whose extent was correlated to the transgene expression level. Four pathogen stress response genes were significantly induced in the transgenic plants, suggesting a putative function of VvERF045 in biotic stress defense during berry ripening. Further molecular analysis on the transgenic plants will help in identifying the actual VvERF045 target genes and together with the phenotypic characterization of the adult transgenic plants, will allow to extensively define the role of VvERF045 in berry ripening.

Vendemmia meccanica: aspettative, problematiche e risposte sperimentali

Lo vendemmia meccanica incontra ancora resistenze legate al timore di peggiorare la qualità del prodotto e di avere elevate perdite di raccolta. In questo contesto sono state effettuate quattro prove sperimentali, finalizzate a definire le interazioni macchina, pianta e prodotto raccolto e a valutare nuove possibilità di regolazione delle vendemmiatrici e di gestione del prodotto raccolto. Le prime due sono state realizzate con vendemmiatrici a scuotimento orizzontale e verticale. L’obiettivo è stato quello di individuare l’influenza della frequenza del battitore sull’efficienza di raccolta e sulla qualità del prodotto e di verificare il maltrattamento provocato dagli organi di intercettazione e trasporto della vendemmiatrice. I risultati hanno dimostrato l’importanza della corretta regolazione del battitore delle vendemmiatrici a scuotimento orizzontale che operano direttamente sulla fascia produttiva del vigneto. Questa regolazione risulta più semplice sulle macchine a scuotimento verticale che agiscono indirettamente sui fili di sostegno delle doppie cortine. La misura delle sollecitazioni all’interno della macchina ha evidenziato valori anche elevati, pericolosi per l’integrità del prodotto raccolto, legati alla differente costruzione degli organi d’intercettazione e trasporto. La terza prova ha valutato l’efficacia di due nuovi accessori per le vendemmiatrici: la regolazione dell’ampiezza del battitore e un sensore per misurare in continuo il grado di ammostamento provocato. I risultati hanno dimostrato la loro validità per migliorare le prestazioni operative delle vendemmiatrici e per fornire agli operatori uno strumento di controllo in tempo reale sulla qualità della raccolta. Infine, considerando che le vendemmiatrici producono sempre un ammostamento dell’uva, abbiamo verificato un sistema innovativo che permette di anticipare la protezione del mosto libero già durante il trasporto dal campo. Il sistema si è dimostrato semplice, efficace ed economico. Queste esperienze hanno dimostrano che la vendemmia meccanica, se correttamente gestita, permette di ottenere ottimi risultati sotto il profilo qualitativo, tecnologico ed economico.

Untersuchungen zur Lebensweise und zur Populationskontrolle des Gemeinen Ohrwurms Forficula auricularia L. (Insecta, Dermaptera) in Rebanlagen

Der Gemeine Ohrwurm (Forficula auricularia LINNAEUS 1758) wurde bisher im Weinbau als natürlicher Gegenspieler verschiedener Rebschädlinge zu den Nützlingen gezählt. Etwa seit 2005 verursacht er aufgrund stark ansteigender Populationsdichten Schäden in pfälzischen Rebanlagen. Ohrwürmer halten sich massenhaft in den Trauben auf. Zusammen mit ihren Exkrementen geraten sie bei der Lese in großer Zahl ins Erntegut. Die Tiere werden von der weinbaulichen Praxis als sehr störend und qualitätsmindernd empfunden und ihre Einstufung als Nützling kritisch gesehen. Aufgrund dieser Problematik wurde im Mai 2007 ein durch den Forschungsring des Deutschen Weinbaus (FDW) finanziertes Forschungsprojekt am Dienstleistungszentrum Ländlicher Raum Rheinpfalz in Neustadt an der Weinstraße begonnen. Bis 2010 wurden offene Fragen zur Erfassung und Populationsbiologie des Gemeinen Ohrwurms in Rebanlagen bearbeitet, die von ihm verursachten Schäden beschrieben und Strategien zu seiner Befallsregulation entwickelt. Am Boden aktive Ohrwürmer wurden mit Bodenfallen nach BARBER (1931) aufgenommen. In der Laubwand des Rebstockes wurden die Ohrwürmer mit eigens konzipierten Bambusfallen erfasst. F. auricularia ist in pfälzischen Rebanlagen die dominierende Ohrwurm-Art. Im Projektverlauf wurde der univoltine Entwicklungszyklus des Gemeinen Ohrwurms in pfälzischen Rebanlagen vollständig aufgeklärt. In der Vegetationsperiode beeinflussten die Intensität der Bodenbewirtschaftung mit der resultierenden Flächenbegrünung, die Bodenart, die Lufttemperatur, die Luftfeuchtigkeit und die Niederschlagsmenge die Befallsdichten am Rebstock signifikant. Der Ohrwurm-Befall in den Trauben war signifikant von der Kompaktheit und vom Gewicht der Trauben sowie dem Fäulnisanteil pro Traube und von eingewachsenen Rebblättern in den Trauben abhängig. Das Überwinterungs- und Brutverhalten wurde durch die Art und Weise der Bodenbewirtschaftung beeinflusst beziehungsweise gestört.rnLabor- und Freilandversuche haben gezeigt, dass F. auricularia Pilzpathogene wie die Graufäule (Botrytis cinerea PERSOON 1794) und den Pinselschimmel (Penicillium crustosum THOM 1930) auf gesunde Trauben überträgt. Ferner haben Fraßversuche ergeben, dass der Ohrwurm nur faule und vorgeschädigte Beeren anfressen kann und keine intakten Beeren verletzt. Durch analytische und sensorische Untersuchungen wurde festgestellt, dass Ohrwurm-Kot sensorische Fehltöne im Wein verursachen kann. Diese werden durch das im Kot enthaltene 2-Methyl-1,4-benzochinon hervorgerufen, das eine Komponente des arteigenen Abwehrsekrets ist. Da sich der Ohrwurm jahreszeitlich bedingt entweder im Boden oder am Rebstock aufhält, wurden befallsregulierende Maßnahmen im Boden- und Laubwandbereich der Rebanlage durchgeführt. Durch Tiefengrubbern mit Umbruch der Begrünung im Herbst und Frühjahr wurden die überwinternden Imagines und die Gelege geschädigt, so dass in der darauf folgenden Vegetationsperiode die Befallsdichten in der Laubwand geringfügig aber nicht signifikant abnahmen. Die während der Aufwanderungsphase der Ohrwürmer Ende Juni durchgeführte mechanische Störung der Begrünung reduzierte den Ohrwurm-Befall am Rebstock bis zu drei Wochen nach der Maßnahme signifikant. In der Laubwand der Rebstöcke wurden die Befallsdichten durch die Insektizide SpinTor (Wirkstoff Spinosad: 0,01%) und Steward® (Wirkstoff Indoxacarb: 0,0125 %) sowie sekundär durch partielles Entblättern der Laubwand dauerhaft bis zur Traubenlese reduziert. rn

Weinproteine - Allergenität und Trubbildung

Wein ist eine komplexe Lösung bestehend aus verschiedensten Komponenten wie Alkohol, Polyphenolen, Polysacchariden, Sulfiten und auch Proteinen. Auch wenn Proteine nur in geringen Mengen im Wein enthalten sind, beeinflussen sie die Qualität maßgeblich. Hier ist zum einen deren potentielle Unverträglichkeit bis hin zur Allergie zu nennen, und zum anderen der Einfluss der Weinproteine auf die Trübung. Im Rahmen einer epidemiologischen Studie der Arbeitsgruppe Fronk/Decker wurde festgestellt, dass es in der Weinregion Mainz ein starkes Interesse gibt die Ursache einer Weinunverträglichkeit zu untersuchen. Für weiterführende Untersuchungen wurde im Rahmen meiner Arbeit das Lipid Transfer Protein (LTP), welches als einziges Allergen der Traube bekannt ist, aus Trauben und Wein in hohem Reinheitsgrad isoliert. Es konnte gezeigt werden, dass dessen Struktur bei der Weinherstellung nicht maßgeblich verändert wurde. In einer klinischen Studie mit 29 Probanden wurde die potentielle Allergenität von Weinproteinen, im Besonderen des LTPs untersucht. Allerdings konnte bei den untersuchten Probanden keine echte IgE-Antikörper-vermittelte Allergie auf das LTP nachgewiesen werden. Daher wird die Ursache der beschriebenen Unverträglichkeiten bei anderen Weininhaltsstoffen oder auch auf pollenassoziierten Kreuzreaktionen vermutet. Bei der Entstehung einer Weintrübung sind zahlreiche Inhaltstoffe beteiligt. Die Rolle der Proteine ist in diesem Zusammenhang noch nicht abschließend geklärt. In dieser Arbeit wurde die Komplexität der Proteinzusammensetzung in Abhängigkeit von Lage, Jahrgang, Rebsorte sowie Behandlungsmaßnahmen gezeigt. Hinsichtlich der Stabilisierung und Trübungsrelevanz der Weinproteine konnte mittels biochemischer, bioinformatischer und biophysikalischer Methoden gezeigt werden, dass nur ein Teil der im Wein enthaltenen Thaumatin-ähnlichen Proteine und Chitinasen an der Trubbildung beteiligt sind. Die Invertase hingegen denaturiert erst ab einer Temperatur von ca. 83 °C und aggregiert in der Trübung. Somit führt dieses Protein bei Wärmetests zu Bentonitbedarfsermittlung in diesem Temperaturbereich zu einer Überschätzung. Die Versuche zur temperaturabhängigen Aggregation von Proteinen zeigen, wie wichtig die Berücksichtigung der Umgebungsfaktoren bei der Trubbildung ist. So konnten unterschiedliche Wechselwirkungen im Puffer- und realen Weinsystem von potentiell trübungsstabilisierenden Polysacchariden mit den Weinproteinen detektiert werden. Für das Arabinogalactan beispielsweise wurde in den Versuchen im Weinsystem eine destabilisierende Wirkung gefunden, während es bei den Versuchen im Puffersystem eine positive Wirkung auf die Stabilisierung der Probe zeigte. Es zeigte sich, dass die verschiedenen Weininhaltsstoffe in einer komplexen Wechselwirkung zueinander stehen und somit eine molekulare Interpretation erschweren.

An underestimated record breaking event – why summer 1540 was likely warmer than 2003

The heat of summer 2003 in Western and Central Europe was claimed to be unprecedented since the Middle Ages on the basis of grape harvest data (GHD) and late wood maximum density (MXD) data from trees in the Alps. This paper shows that the authors of these studies overlooked the fact that the heat and drought in Switzerland in 1540 likely exceeded the amplitude of the previous hottest summer of 2003, because the persistent temperature and precipitation anomaly in that year, described in an abundant and coherent body of documentary evidence, severely affected the reliability of GHD and tree-rings as proxy-indicators for temperature estimates. Spring–summer (AMJJ) temperature anomalies of 4.7 °C to 6.8 °C being significantly higher than in 2003 were assessed for 1540 from a new long Swiss GHD series (1444 to 2011). During the climax of the heat wave in early August the grapes desiccated on the vine, which caused many vine-growers to interrupt or postpone the harvest despite full grape maturity until after the next spell of rain. Likewise, the leaves of many trees withered and fell to the ground under extreme drought stress as would usually be expected in late autumn. It remains to be determined by further research whether and how far this result obtained from local analyses can be spatially extrapolated. Based on the temperature estimates for Switzerland it is assumed from a great number of coherent qualitative documentary evidence about the outstanding heat drought in 1540 that AMJJ temperatures were likely more extreme in neighbouring regions of Western and Central Europe than in 2003. Considering the significance of soil moisture deficits for record breaking heat waves, these results still need to be validated with estimated seasonal precipitation. It is concluded that biological proxy data may not properly reveal record breaking heat and drought events. Such assessments thus need to be complemented with the critical study of contemporary evidence from documentary sources which provide coherent and detailed data about weather extremes and related impacts on human, ecological and social systems.

Probabilidades de daño por viento Zonda en la floración de frutales, vid y olivos

La agricultura de Mendoza está expuesta a daños producidos por viento Zonda, cuya frecuencia y magnitud no han sido suficientemente estudiadas. Por ello se ha procurado determinar las características de los vientos Zonda y la probabilidad de que sean afectados cultivos de vid, olivo y frutales. Se tuvieron en cuenta los Zondas registrados durante 44 años (1958-2002) por la estación agrometeorológica Chacras de Coria de la Facultad de Ciencias Agrarias de la UNCuyo, en el período de floración de las principales variedades de los cultivos mencionados. El análisis se realizó cada diez días mediante los parámetros que se consignan a continuación: Salto térmico: diferencia entre las temperaturas máximas del día anterior y del día con Zonda, subdividido en las siguientes categorías: leve: 1 a 5 °C; fuerte: 6 a 10 °C; severo: mayor de 10 °C. Poder secante: evaporación del día del evento subdividido en las siguientes categorías: pequeño: 1 a 6 mm/día; grande: 7 a 12mm/día; muy grande: superior a 12 mm/día. Duración del evento, subdividido en las siguientes categorías: corta: 1a 8 hs; larga: 9 a 16 hs; muy larga: superior a 16 hs. La interacción y combinación de estos parámetros en sus diversas magnitudes determina el efecto dañino del Zonda representado a través del Índice Climático de Peligrosidad (ICP) de los vientos, que demues tra que todo el período estudiado tiene algún grado de riesgo. Se concluye que: El 47 % del total de casos de viento Zonda corresponde a agosto y la primera semana de septiembre. Las probabilidades de ocurrencia de un salto térmico severo están circunscriptas a agosto y primeros días de septiembre. En todo el período existen probabilidades superiores al 2 % de que ocurra un Zonda con poder secante muy grande. Eventos de muy larga duración tienen relativamente alta probabilidad de ocurrencia en agosto y primeros días de septiembre. Se puede determinar la probabilidad de daño para un cultivo confrontado los valores del ICP con la fenodata de plena floración correspondiente, lo cual constituye una herramienta para la defensa pasiva. Se suministran las fenodatas de las principales variedades de vid, olivo, duraznero y ciruelo, que son las especies cultivadas más importantes en el área de influencia de la estación agrometeorológica de Chacras de Coria.