La viticoltura biologica e' una realtà
La viticoltura biologica non è un utopia ma una realtà. Metterla in pratica richiede delle conoscenze di base non comuni ma sicuramente non difficili da acquisire. Pazienza e volontà sono alla base di questo tipo di agricoltura.
Il vigneto è un agroecosistema che si presta ad un agricoltura biologica più facilmente delle altre colture. Infatti il vigneto ha un alto potenziale ecologico per diverse ragioni:
-E’ una pianta perenne
-Le avversità della vite non sono numerose rispetto ad altre piante da frutto
-I fitofagi chiave possono essere controllati con diversi metodi di protezione
Il passaggio da monocoltura in un agroecosistema complesso può essere attuato con l’uso di infrastrutture ecologiche, sovesci etc.
Il punto di partenza per realizzare un vigneto biologico è incrementare la biodiversità animale e vegetale per potere controllare le avversità che tendono a danneggiarlo. Essendo una coltura perenne è possibile in pochi anni incrementare la biocenosi all’interno dell’agroecosistema riuscendo cosi a ridurre quasi del tutto gli attacchi di insetti e acari dannosi. L’incremento della biodiversità si realizza attraverso l’uso di alcune piante non produttive e non coltivate nell’agroecosistema vigneto che infestandosi con fitofagi non nocivi per la vite consentono la moltiplicazione, l’alimentazione e/o il rifugio di predatori e parassitoidi dei fitofagi chiave del vigneto. Queste piante possono essere distribuite in zone non coltivate del campo per formarele aree di compensazione ecologiche, oppure intorno ai vigneti e formare cosi le infrastrutture ecologiche. Ma la biodiversità si incrementa anche in altri modi, come attraverso i sovesci, le poche coltivazioni etc. Cercherò in questo sito di consigliare e spiegare come gestire i vigneti in biologico dimostrando come è l’unica gestione razionale ed economica possibile in un mondo agricolo che non paga il duro lavoro e non rispetta più l’ambiente e l’uomo stesso.
Ecological infrastructures in a vineyard of West Sicily
Lo Genco A., Fucarino A. and Lo Pinto M.
Dipartimento S.En.Fi.Mi.Zo. Sez. di Entomologia, Acirologia e Zoologia. Università di Palermo,Italy.alo_genco@hotmail.com
Abstract. Cultural methods such as excessive use of fertilizers, pesticides and monocultures have decreased agrobiodiversity and created more favourable conditions to increase insect pests and diseases levels in agroecosystems. Monoculture is a concentrated resource for specialized pests, which increases the attraction and accumulation of these species, the time they spend in the system and their reproductive success (Altieri, 1993). Furthermore, expansion of monocultures has decreased abundance and activity of natural enemies due to removal of food sources (i.e. nectar, pollen and often honeydew), refuges and hibernation sites. Some researchers have proposed to increase agro-biodiversity by creating an appropriate ecological infrastructure within and around the agro-ecosystem to favour the abundance and effectiveness of natural enemies. The maintenance and management of ecological infrastructures, or ecological compensation areas (ECAs), on rural farms is considered crucial in enhancing functional biodiversity for pest suppression (Boller et al., 2004). In autumn 2006, we start cooperating with a young winery (www.funaro.it) located in Marsala area. In order to enhance biodiversity we have introduced ecological infrastructures in 2 hectares vineyard of Merlot variety. We have planted several plants of bramble (Rubus spp.), oregano (Origanum vulgare L.), rosemary (Rosmarinus officinalis L.), wild rose (Rosa canina L.), oak (Quercus pubescens Willdenow) all around Merlot vineyard. These plants should provide refuges, hibernation sites, alternate host animals, prey for the juvenile stage of predators, resources for a successful immigration and reproduction of natural enemies of key pest in viticulture (Boller et al., 2004). The role of ecological infrastructures in vineyard is still not well understood and their use to manage vineyard pests is a controversial practice. This work aims to study the possible effects of ecological infrastructure on arthropod associated to a vineyard.
Introduction
Conservation biological control is a pest control strategy based on the manipulation of wild populations of natural enemies to enhance their impact on pest by habitat management and by maintaining ecological infrastructures (Boller et al., 2004).To improve conservation biological control requires a detailed basic knowledge of the trophic relationships among ecological non-crop plants, phytophages and beneficials (Burgio et al.,2006).
Adequate ecological infrastructures provide refuges, hibernation sites,alternate host animals, prey for the juvenile stages of predators, and with flowering plants the essential food sources for maturation and reproduction of all adult parasitoids, many predators and pollinators. Thus, each plant species have an important function in natural pests regulation because act as important sources of natural enemies of key pest. In the agro-ecosystem vineyard, the influence of such hedgerows inside and outside production sites on grape pest management has been investigated by several authors (Nicholls et al., 2001;Boller et al., 2004; Ponti et al., 2005).
For example, the egg parasitoid Anagrus spp.(Mymaridae), the most important natural enemy of the grape leafhoppers, spends the winter as egg in leafhopper eggs deposited in bramble and wild roses (BOLLER et al., 2004). Research by Ponti et al. (1984) established that intenance of the bramble hedge surrounding vineyard is therefore advisable to promote early Anagrus colonisation leading to an effective control of grape leafhoppers. The aim of the present research is to study the influences of ecological infrastructures on biodiversity and their role in grape pest management.
Materials and Methods
Study region
The cultivation of vine and the production of wine are spread in all the Sicilian territory and the ampelographic wealth of the island is pretty interesting. Sicily is Italy’s biggest wine producer and it has also the biggest area cultivated in vineyard.Efforts made in the last twenty years have allowed the revaluation of many autochthonous grapes of the island and now - after having concretely faced extinction - are considered among the most important grapes of Italy. In the region are also cultivated many international grapes, mainly used for blends with local grapes (Cabernet sauvignon, Merlot, Syrah, Chardonnay, etc.).Funaro Property has more than 50 ha of vineyards, between native and international varieties.The vineyards are located between Salemi and Marsala, right at the heart of this area with a marked vine-growing vocation. In this area an excessively aggressive viticulture has no permitted the conservation of some main natural area where the natural flora and fauna can grow up. Going across this area is easy to understand how the agro-ecosistem is altered and the necessity of a rapid restoring is vital for achieve a correct integrated or organic viticulture. The commitment and openness of Funaro family has permitted to start an interesting research on ecological infrastructures, planted them around and inside their property, and also using specific cover crops during the raining moths.Funaro family with our experience and help is converting all the vineyards from a conventional viticulture to a modern and organic viticulture (www.funaro.it).
Study site
This experiment is conducted in a 2 ha Merlot organic vineyard, located in Salemi (situated 400 m above sea level), 10 Km from Marsala (Sicily), a typical wine growing area. The vineyard is affected yearly by various pathogens, insects, and mites.Downy mildew (Plasmopara viticola B. et C.), powdery mildew (Uncinula necator Schaw.) and bunchrot (Botrytis cinerea Pers.) are the most prevalent fungal pathogens of grapes in the area.Among insect pests, leafhopper (Jacobiasca lybicaBergevin & Zanon and Zygina rhamniFerrari) is the most persistent one. Others local key pests are, grape moths, spider mites and thrips. Vineyard is protected yearly with preventive applications of two fungicides, Bordeaux mixture and sulphur. No insecticides is applied. In the autumn 2007, in order to enhance biodiversity, several young plants of bramble (Rubus spp.), oregano (Origanum vulgare L.), rosemary (Rosmarinus officinalis L.), wild rose (Rosa canina L.), oak (Quercus pubescens Willdenow) were planted all around the perimeter of the Merlot vineyard. Furthermore, winter cover crops (a mixture of barley, Hordeum vulgare L. and vetch, Vicia narbodensis L. cv velo) are planted yearly in an alternating row pattern. Brambles and wild roses are an important source for predatory mites and Mymarid parasitoids such as Anagrus sp. (BOLLER et al., 2004); Rosemary and oak are important plants for development of lepidopteran parasitoids and predatory mites (RAGUSA & TSOLAKIS, 2005); oregano is a good nectar source for parasitoids andpredators.
Sampling procedure
In order to determine the species diversity and densities of prevalent herbivores and predators/
parasitoids associated with the ecological infrastructures, insects and mites on each hedge are sampled by mechanical knock-down (MKD) every 15 days, by visual inspections (VIS) every 7 days(Burgio et al.,2004). Also, the entomofauna are sampled by randomly placing yellow and blue sticky traps in grape and in the hedges. Lobesia botrana Denis et Schiffermüller are monitored by direct count on inflorescences or bunches and by pheromone traps placed in the vineyard. All traps are returned to the laboratory and examined under a stereomicroscope to identify and count the number of phytophagous insects and natural enemies.
Results and Discussion
Preliminary observation conducted in this vineyard during 2005 and 2006, before planting ecological infrastructures, showed among the prevalent species of pests, species such as Z. rhamni and J. lybica. The leafhoppers population increased from May to the beginning of September reached the highest peak at the end of September with 0.5 leafhoppers/leaf. During the visual examination of the leaves in the field, several species of dragonflies were seen to prey leafhoppers. The tortricid moth, L. botrana, was also present with a low density, total yearly captures ranged from 0 to 3 males/ pheromone trap. Moreover, ours preliminary data suggest that vineyard exhibit higher level of predator families such as Coccinellidae, Crysophidae, and Syrphidae, but they don’t show what parasitoid species are present. At the present time, ecological infrastructures are one year old and there aren’t insects in their young leaves. Ours challenge is to identify the hedges that are desirable to maintain in the vineyards in order to carry out specific ecological services such as pest regulation.
References
Altieri M. A., 1993.Ethnoscience and biodiversity: key elements in the design of sustainable pest management systems for small farmers in developing countries.Agriculture, Ecosystems and Environment, 46 257-272.
Boller E. F., Hani F., Poehling H.-M., 2004.Ecological infrastructures. Ideabook on functional biodiversity at the farm level.- IOBC/wprs, Lindau, Switzerland.
Burgio G., Ferrari R., Boriani L., Pozzati M., Van Lenteren J.,2006. The role of ecological infrastructures on Coccinellidae (Coleoptera) and other predators in weedy field margins within northern Italy agroecosystems.Bulletin of Insectology 59 (1): 59-67.
Nicholls C. I., Parrella M. & Altieri M. A., 2001.The effects of a vegetational corridor on the abundance and dispersal of insect biodiversity within a northern California organic vineyard.Landscape Ecology 16: 133–146.
Ragusa S. & Tsolakis H., 2006. La difesa della vite dagli artropodi dannosi. Università degli studi di Palermo.