ACTIVITY OF NATURAL PRODUCTS AGAINST SOME PHYTOPATHOGENIC FUNGI.

The requirement of environmental protection and food safety is perceived with always major interest by public opinion and it is consistent with European Union legislation on the sustainable use of pesticides (Directive 2009/128/EC). This directive requires member states to promote low pesticide-input, giving priority to non-chemical methods and low risk plant protection products. In order to contribute to the achievement of these objectives antifungal activity of natural substances, characterized by a good toxicological and ecotoxicological profile, was tested. Essential oil of Melaleuca alternifolia, essential oil of Syzygium aromaticum and extract from Mimosa tenuiflora were tested against Alternaria alternata, Botrytis cinerea and Fusarium oxysporum f. sp. lycopersici (races 1 and 2). In vitro tests involved determination of radial growth of the colonies of fungi in the presence of varying concentrations of tested products in agar media and determination of germination percentage in the presence of tested product at various concentrations. The products based on essential oil of M. alternifolia were also tested in vivo on tomato fruits wounded and artificially inoculated with A. alternata or with B. cinerea. The in vitro tests showed the antifungal activity of both essential oils instead the extract from M. tenuiflora exhibited poor antifungal activity and only against A. alternata and B. cinerea. The results on tomato fruits showed inhibition of grey mould and black mould by essential oil of M. alternifolia. The antifungal activity increased with increasing concentrations. In conclusion, the obtained results in the present study showed promising prospects for the utilisation of investigated products to reduce the using of antifungal chemicals and to achieve a more sustainable use of pesticides.

Optimization of plant protection products treatments against Plasmopara viticola.

Plant protection in conventional farming, and even more so in organic farming, requires careful and prudent action agro-environmental monitoring and epidemic risk assessment. Often, however, the plant protection products are distributed in a non-targeted way, even when reduced incidence of pests do not require any treatment. In order to optimize the treatments against downy mildew, multi-annual field trials, both in conventional and organic vineyards, have been carried out. In all farms were considered 3 thesis: 1 untreated control thesis (Test), in order to follow the coarse of infection, 1 standard farm reference thesis (St), where the treatments were carried out according to the usual farm procedures and 1 experimental thesis (X). Guideline EPPO/OEPP PP 1/31 (3) have been carried out. We monitored different environmental parameters capable to influence Plasmopora viticola (Berk. and Curt.) Berl. and De Toni development. In fact by a network of RTUs (Remote Terminal Units) distributed all over the vineyards transmitting every 15 minutes via radio or via GPRS to a centralized Data Base 12 environmental parameters: time, data, precipitation, soil temperature, solar radiation, wind direction, wind speed, atmospheric relative humidity, atmospheric temperature, leaf wetness, soil humidity to cm 20 and soil humidity to cm 40. In different phenological growth stages we carried out careful disease assessments on leaves and bunches to evaluate the onset and development of P. viticola. We have studied the downy mildew infections through monitoring the environmental parameters, knowledge of P. viticola biological cycle, the evaluation of cultivar sensibility, the agricultural production method and the area characteristics, to try to optimize the anti- downy mildew treatments. The achieved results have underlined the possibility to obtain a satisfactory protection against P. viticola by correct placing of treatments. In experimental thesis (X) the number of treatments was generally lower than the number made on the thesis standard (ST), with efficacy comparable if not better. This result is most evident in conventional farms where surveillance is less accurate because is can also use plant protection products with a curative action. The trial showed the possibility of obtaining real cost containment management and a lower environmental impact associated with reduced fungicidal treatments.

Rationalization of pesticide treatments against powdery mildew of grape.

The powdery mildew represents one of the diseases which affect the grape, it is diffused in all agricultural regions with variable intensity and epidemic course in operation of many microclimatic factors. The powdery mildew of grape is caused from Uncinala necator (Schw.) Burr. (nowadays named Erysiphe necator Schwein.); it is controlled with systemic therapy and contact chemicaL products. In some vineyards located in Latium (central Italy), different field trials have been carried out purposely to rationalize the treatments against E. necator. We have studied the powdery mildew infections through monitoring a set of environmental parameters, the evaluation of cultivar sensibility, the agricultural production method and the area characteristics. We have analysed the following environmental parameters monitoring every 15 minutes: precipitation, soil temperature, solar radiation, wind direction, wind speed, atmospheric relative humidity, atmospheric temperature, leaf wetness, soil humidity to cm 20 and soil humidity to cm 40. Besides, we have used Artificial Intelligence analysis techniques to try to forecast U. necator infections. Guideline EPPO/OEPP PP 1/4 (4) has been used. The trials were conducted in conventional and organic farms. In 2 conventional farms and in organic farm we have considered 1 untreated control thesis, in order to follow the course of infection, 1 standard farm reference thesis (standard), where the treatments were carried out according to the usual farm procedures and 1 thesis where the treatments were carried out according to examining the environmental data. In another conventional vineyard, we have considered only 1 untreated control thesis and 1 standard farm reference thesis (standard) to study disease trend. The achieved results have underlined the possibility (through the knowledge of data pedoclimatic and cultural) to position the treatments against the powdery mildew so that to reduce their number. The lower number of treatments that could follow as a result of environmental data to analyse could bring a series of evident economic and ecologic advantages for the farms.

A two years study results in the use of artificial neural networks to forecast Plasmopara viticola infection in viticulture.

This paper describes the further results of the study that has been described in session 5 of the 58th International Symposium on Crop Protection (Ghent 2006). Since then our attention has been focused on verifying the previous communication results working on a two years basis data set belonging to a specific farm. The choice of using data from a single farm derives from the considerations that have been explained in the previous study in which it was clear that an efficient forecasting Artificial Neural Network (ANN) model can be created only in restricted (or at least comparable) pedoclimatic areas. On the basis of the matured experience, at the moment we have realized an ANN which, being trained on 2005 year data, elaborating the following year data is capable of correctly predicting the real Plasmopara viticola (Berk. et Curt.) Berl. et De Toni outbreak, never giving false negative signals (no alarm in presence of infection on the field) and, finally, giving few other alarms which are totally comparable with the ones given by the most common statistical instrument used in this field trials. We confirm the advantages of this approach in terms of: (a) Management and optimization improvement of agricultural activities. (b) Reduction of plant protection products use. (c) Quality improvement of the final product for a real lowering of plant protection products use. (d) Reduction of environmental impact. (e) A more efficient management of the climate changes.

More years of field trials against Plasmopara viticola in organic viticolture.

The organic viticulture assumes a decisive role in the national agricultural sector. More impelling problems in the management of organic vineyards are represented from the plants pathology defence and particularly of Plasmopara viticola containment. Copper represents one of the few usable fungicides in the organic farming and the only effective against downy mildew. With Regulation EC n. 473/2002, fixed maximum quantity usable of copper compounds, owing to the environment problems due to the copper accumulation in the soil. To reduce quantity of metal copper or replace it with natural products, are conducted field trials with copper compounds at a low rate or alternative to copper products. Besides, we are estimating possibility to reduce the operations against P. viticola optimizing fungicidal treatments. Field trials in the organic farms located near Rome, have been carried out. Guidelines EPPO/OEPP PP 1/31 (3) have been carried out. The results of the trials have showed that, using cupric products with low metallic content, to reduce copper quantities used, always allowed to respect the limits established by Regulation EC. The alternative products that were investigated have not guaranteed, instead, an adequate protection in high pressure of grapevine downy mildew. It was possible to reduce treatments against P. viticola through control of different environmental parameters. The trials confirm that the copper is indispensable for plant protection in organic farming as it is not possible to replace it with natural extracts substances. We can reduce, instead, the copper quantities used trough the use of new products with low quantity metal copper or through the evaluation of climatic and pedologic data that allow to rationalize the fungicidal treatments.