Biological control and natural biomolecules


Testing the efficacy of allowed and alternative products in organic agriculture for the control of the main olive and grapevine pests and evaluation of their phytotoxicity. study of the interactions between vine moth, microorganisms and plants in the

 Background

For the control of the olive fly, the  “Attract and kill” method,  biocides and copper were tested. For the control of powdery mildew, some sulphur-based products and the micro-organism Ampelomyces quisqualis (AQ10) were checked whereas for the grapevine moth, Bacillus thuringiensis var. kurstaki andaizawai. In compliance with the EU directives, which orient towards the use of low-impact products, new microorganisms are investigated for the control of Lobesia botrana.

Botrytis cinerea and some microorganisms like Acetobacter, Gluconobacter, Saccharomyces cerevisiae,and  Bacillus subtilis, are commonly found on the rind of berries. Some of them play a crucial role in the development of the major grapevine diseases (sour rot and grey mould). In the organic vineyards, the relationship between the ecosystem organisms are extremely important. Some data show that the above-cited microorganisms have a role in the attraction/repellence of the vine moth and effect the three senses of L. botrana(smell, sight, touch).

Several research activities were conducted to compare the efficacy of copper compounds for the control  of downy mildew. Some strategies based on low amounts of copper were set up although only aminoacid- and peptide-chelated copper seems to reduce copper, and to improve copper penetration in the pathogen cells. However, the fast penetration of copper peptidate through the cell membrane increases the risk of toxicity for the plant cells. Copper peptidate (Naturam 5®) was compared with other products: Kocide 2000®(copper hydroxide), Manica 20® (Bordeaux mixture, copper sulphate), Fosfid’or® and Kendal® (mineral nutrients with potassium phosphonate).

Under greenhouse-controlled conditions, tests were made on the impact of temperature (5, 15, 25 and 35 °C), leaf wetting and number of treatments (1, 3, 5 and 7) on the phytotoxicity of copper peptidate. The effect of these factors was also studied in open field conditions in Apulia and in Trentino region.

Climatic conditions were monitored during the whole trial. The efficacy of various products was monitored weekly both on leaves and bunches.

Control of powdery mildew was ensured by sulphur-based products which, however, may be toxic for the flora, fauna and humans. New control techniques were thus studied which should limit their use; they include some antagonists such as mycophages, bacteria, yiests and fungi. The environmental characteristics in which they develop are important: nutrients, infrared and ultraviolet radiation, water and temperature heavily impact their efficacy. Before their use in the field, accurate studies are needed on their survival ability in different environmental conditions.

Moreover,  some evaluations were made on an epiphytic yiest isolated in Israelwhich is a potential agent for the biological control of powdery mildew, on KBV, which is a lactoperoxidase enzyme and on a bacterium.

A sound biological control calls for an in-depth knowledge of the entomocoenosis. Therefore, some studies on the olive agroecosystem were kicked off for the identification of antagonists (predators, parasitoids) some of which may maintain control over the populations of several olive pests. The various components of the entomocoenoses are regulated by complex functional relationships which may be altered by broad-spectrum pesticides and/or by too invasive agricultural practices. The impact of agricultural activities and of chemical treatments on the environment is more and more often studied through the characterization of entomocoenosis and of non-target insects. Among the latter are some groups which may play the role of bioindicators although for the olive grove the best bioindicator has not been found yet. 

Timing:
Starting: 2.01.2000
Scheduled ending: 30.12.2009
Real ending: 25.06.2019
Objectives:

 Objectives

Setting up strategies for the control of downy mildew, powdery mildew and European grapevine moth for table and wine grapes; control of olive fly, margaronia and scale for olive. Evaluation of  the efficacy of copper peptidate and of its phytotoxicity with respect to other traditional copper-based compounds in variable climatic conditions.

The phytotoxicity of copper peptidate was assessed on eight wine and table vine cultivars (Victoria, Italia, Red Globe, Primitivo, Negroamaro, Uva di Troia, Cabernet Sauvignon and Chardonnay) and potential factors increasing the risk of copper damages on the leaves were identified.

Moreover, in controlled conditions (in vitro) evaluations were made relating to the survival of an epyphitic yeast, of a lactoperoxidase enzyme and of a bacterium. In the field, their efficacy was tested in the control of powdery mildew on Chardonnay.

It was also tried to understand whether a biocontrol agent like Metschnikowia fructicolawhich is effective against B. cinereain the organic vineyards may have a role against the main grapevine moth.

For the characterization of entomofauna, the aim is to monitor entomocoenosis at two levels: flying and walking insects. 

Justification:

 Justification

Checking the efficacy of control strategies for grapevine and olive based on the technical means allowed by the regulation 2092/91 Annex II. Moreover, the control of Plasmopara viticola in organic viticulture is nearly exclusively based on the use of copper which is toxic for the environment since it has a long residual activity on micro- and macro-organisms in the soil. This is why the EU has issued regulations for the phasing out of copper. Restrictions on the use of copper have stimulated the research towards alternative products  and optimized the use of the maximum copper amount allowed (6 kg/ha/year). In the Mediterranean organic viticulture, powdery mildew is controlled with sulphur. Over the last years, several researchers have highlighted the necessity to reduce sulphur due to some of its side effects such as residues in the wine, eye and skin rush for vine growers, phytotoxicity when applied with high temperatures and inhibition of bacterial activity during fermentation with loss of typical aromas. This is why products with a low impact are under identification for the control of the fungus.

Entomofauna characterization will help gathering data about fauna in Puglia. Moreover, it will examine the effect of the macroclimate on insects and develop a monitoring protocol of insects to be used as bioindicators. 

Potential:

 Potential

Research works have enabled to validate control strategies in the olive growing sector and in viticulture in several areas (Puglia, Albaniaand Greece) so as to transfer the results attained to the organic farms.

Furthermore, the results of some works will make it possible to understand the complex relations between insects, pathogens and crops in the organic agroecosystem, to investigate the attractiveness and repellence of some micro-organisms on the berries, and to respond to some basic ecological queries  thereby opening new frontiers to biological management.

Results:
Notes:

   Remarks

    • Strengths

The research work has allowed to transfer all the indications for a correct management of organic farms.

It is the first study carried out in Apulia on organic farms for the characterization of entomofauna. This activity has already enabled to detect two new species which may be used in the biological control strategies.

    • Weaknesses
It is difficult to monitor trials made abroad. As to the entomofauna characterization, the support of a research project is needed in order to team up with other scientific institutions.
Reference person/s: Simeone Vito /
Collaborators: Cesari Gianluigi / Petruzzella Damiano / Tucci Michele /
Thesis:
Institutions involved:
 
 
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