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Com. 17

Compared leaching risk of atrazine and other maize herbicide (sulcotrione).

CHERRIER Richard, PERRIN-GANIER Corinne and SCHIAVON Michel

Soils and Environment Laboratory,

ENSAIA-INRA/INPL, UMR 1120. 54 505 Vandoeuvre-lès-Nancy. France

e-mail: [e-mail]

Keywords: Organic micro pollutant, atrazine, sulcotrione, soil and water pollution
Atrazine is frequently recovered in surface and underground water. Recommendations in terms of treatment for maize are most of the time corresponding to a diversification in the products used. Amongst these, sulcotrione already proved its agricultural performances and could be used systematically. However, at an environmental level, its fate remains poorly elucidated. It is also important to assess its risks of soil and water pollution and also to compare with that of atrazine. The aim of the present work was to investigate the possibilities of sulcotrione and atrazine transfer by leaching on soil columns under natural climatic conditions.

The soil selected presents a sandy-silty texture and the soil columns were taken in situ in order not to alter the soil structure. Column treatment was performed with a solution of either sulcotrione or atrazine labeled with ¹⁴C on the benzene ring. The treatment corresponded for both sulcotrione and atrazine to an input of agricultural recommended rates. Columns received natural rain and artificial irrigation because of a low pluviometry. Soils columns were collected 0, 15, 30 and 60 days after treatment. Herbicides concentrations were measured in soil after extraction and in leachates by  liquid scintillation counting.

The results of this work underline that sulcotrione leaches easily and in the same range than atrazine. When we compare sulcotrione leaching and concentration in different depths of soil, we can conclude that sulcotrione has a behaviour rather similar to atrazine’s. Risk of soil and water pollution with sulcotrione is therefore comparable to that of atrazine, when studied in same conditions.

We can conclude that a general use of sulcotrione in maize treatment could lead to the same environmental situation than that of atrazine.

Com. 18
An indicators for pesticides vineyards environmental assessment : IPHY indicator.
Marie THIOLLET, Philippe GIRARDIN.
INRA, 28, rue de Herrlisheim 68000 Colmar. FRANCE.
To do the evaluation of pesticide field diagnosis, we propose a viti-ecological indicator : Iphy. Its purpose is environmental evaluation of risk for water, air, soil and beneficial organisms. Iphy is based on a expert system associated to fuzzy logic. Several variables are distinguished : some dealing with active compounds of pesticides, others dealing with the field and finally variables dealing with pesticides application way. This indicator has been tested during three years with pesticide programs of 45 vineyards farms in the Northeast of France. The Iphy software is adapted to build pesticides risks lists usable by the winegrowers and vineyards advisers. Key words : environmental impact, vineyard, indicator, field scale, pesticide, expert system, fuzzy logic, instrument panel, field scale.

Figure 1 : Decisions rules for modules aggregation (1) ; Reso module « leaching risk » ; Resu module « runoff risk » ; Rair module « air risk » ; Rate « rate of application ».

Figure 2 : Decisions rules for modules aggregation (2). Env : aggregation of modules Reso, Resu, Rair et Rate; Raux module « beneficial organisms risk ».

Figure 3 : Iphy calculation for Burgundy farms between 2000 and 2002

Com. 19

Pretilachlor and fenclorim in rice: persistence, detoxification, safening effect and carbohydrate formation.

Luciano SCARPONI^a, Daniele DEL BUONO^a, Costantino VISCHETTI^b

^aDipartimento di Scienze Agroambientali e della Produzione Vegetale – Università degli Studi di Perugia, Borgo XX Giugno 72, 06121, Perugia (Italy)

^bDipartimento di Biotecnologie Agrarie ed Ambientali – Università degli Studi di Ancona , Via Brecce Bianche 60131 Ancona, (Italy.)

The content and persistence of pretilachlor (P) and of the safener fenclorim (F) in rice treated with P, F and their mixture P+F were investigated in relation to their detoxification mechanism and in connection with starch and glucose formation, checked as a disturbance index following the treatments.

The presence of F did not reduce the accumulation of P in rice shoots, whereas it was able to reduce P persistence; on the other hand, the presence of P did not reduce the persistence of F whereas it determined a greater than two-fold F accumulation in the shoots. Therefore, a detoxification mechanism common to both the compounds but favourable to P occurred. It proved to consist in an activation of the glutathione-S-transferase enzyme towards P as substrate [GST(P)], in response to all the treatments. The activation levels were found to be proportional to the amount of P or F residues in the plant, and additive following the P+F treatment. The kinetic parameters, V_max and K_m, of GST(P), evidenced an increased expression of the enzyme in the rice plant following all the treatments, and a safening effect of F, consisting in the induction of enzyme-isoforms more sensitive to P.

During the time required for the P and F detoxification, decreases in starch, almost counterbalanced by increases of glucose, were ascertained in the P-treated seedlings, and decreases in both starch and glucose were observed in the F-treated seedlings as compared with the untreated seedlings. These effects were produced at a sublethal level, and proved to be related to reduced activities of the glucose kinase and of the ribulose-1,5-bisphosphate carboxylase enzymes in response to P and F treatment, respectively.

Com. 20