Strategie di riduzione del rischio residuo nella difesa delle colture vitivinicole e del pomodoro

Background: Pesticides are used to control pests and diseases in modern agriculture but unfortunately their residues can be found on agricultural crops, and in the human’s dietary. Although the best way to decrease the risk associated with the presence of pesticides on agro-food is following organic farming techniques, most farmers may not avoid the use of chemicals in pest management strategies. A good approach to the problem should therefore guarantee good agricultural yields and low pesticide residues allowing the use of environmental safety pesticides on crops, so joining consumer’s safeness with farmer’s necessity. Results: The behaviour of various pesticides used in IPM strategies on grapes and tomatoes were studied. All the analytical methods showed good recoveries, and good separation of the molecules. Repeatability and intermediate precision showed good results, and LODs and LOQs were far below the MRLs set by EU for these pesticides in tomatoes and grapes. The analysis of pesticide residues on tomatoes showed that cv. with little berries accounted for higher residue levels than cv. with big berries. They also showed an high persistence of azoxystrobin, cyproconazole, cyprodinil, penconazole, tolclofos-methyl, mepanipyrim, pyrimethanil, famoxadone fenamidone, fenhexamid, iprodione, and a rapid degradation of triadimenol, cymoxanil, iprovalicarb, fenarimol, and fludioxonil. On grapes, the behaviour in field and the transfer to wine during winemaking of iprovalicarb, indoxacarb, and boscalid, was studied. The residue levels found in grapes were far below the MRLs set for grapes in EU, accounting at harvest time 0.81, 0.43, and 4.23 mg/kg for iprovalicarb, indoxacarb, and boscalid, respectively. The residue levels in the samples treated with boscalid may have residual problems (due to an accumulation effect) if repeated field treatments will be performed. Winemaking experiments showed a complete transfer of all pesticide from grapes to the must, while in wine the residues were low or negligible due to the adsorbing effect of lees and pomace. The clarification experiments showed a good removal of pesticide residues from the wine media, for all pesticides. The data obtained in two years survey of pesticide residues on wines following IPM strategies, showed residues less than maximum residue limits (MRLs). The most pesticides present a residue absent, some (benalaxyl, metalaxyl, iprovalicarb, penconazole, cymoxanil and thiophanate-metyl) showed a residual below the minimum limit of detection (LOD). No residues were found above the LOQ (0,01 mg/kg). Conclusions: The obtained data showed the possibility to get tomatoes and wine at "zero residue" or, at least, with residues below the limit of quantification (LOQ). The data collected on tomato have also shown the difference in initial deposition of pesticide joined to the size of the berries in order to obtain products with lower pesticide residues, paying more attention to chemical treatments for the defense of cultivars with small berries.