Impiego di biostimolanti in strategie di difesa di colture ortoflorofrutticole da nematodi fitoparassiti

The european revision of crop pesticides resulted in the disappearance of the most effective nematicides and in the consequent immission on the market of a large variety of biostimulant formulations with a collateral suppressive effect on phytoparasitic nematodes. Results of a market survey of biostimulant formulations active on phytonematodes are presented in this work, with a specific attention to their source materials, mechanisms of nematode suppression and effectiveness, as emerging from literature's data and authors' experimental activity. Survey evidenciated a prevalence of plant and algae-derived products, either in liquid or meal and pellett formulations, which source materials are largely reported for their nematicidal activity. Easy distribution by fertirrigation systems and flexibility of treatments, as appliable before transplant or during the crop cycle, are the main advantages of liquid formulations. Pelletts or meals can be a quicker alternatinative to biocidal green manures in intensive crop systems and generally result in a larger plant growth stimulation. Microbial formulations, generally based on mychorrhizal fungi and plant growth promoting bacteria, may be a highly sustainable nematode control tool, but their effects are largely variable, due to the influence of crop species and variety and of pedoclimatic factors. The large scientific interest in chitosan formulations has still to be confirmed, due to few results on their nematode suppressive effect. The available experimental data seem to indicate that biostimulants can be a valuable tool for sustainable nematode control strategies, either in organic and conventional crop systems. However, due to the cost of these products, a cost-benefit analysis should be always done before their application, as to evaluate the economic convenience of treatments.

La drastica revisione dei pesticidi ammessi in agricoltura operata dalla CE ha lasciato spazio all'immisssione sul mercato di un gran numero di formulati biostimolanti e corroboranti della crescita della pianta in grado di contenere anche gli attacchi di nematodi fitoparassiti, in genere galligeni su colture ortoflorofrutticole. Tali formulati sono generalmente di origine vegetale ed il loro meccanismo d'azione è prevalentemente connesso ad una attività repellente o antifeedant sul nematode target e solo in minima parte alla presenza di principi attivi nematocidi. Il lavoro illustra, l' ampia attività sperimentale degli autori con formulati di varia provenienza ed efficacia.