Though new exotic pests, such as the South American tomato pinworm Tuta absoluta, have recently spread severely in Sicily, rapidly becoming the driving key factor for the integrated management of pests in vegetable crops especially under greenhouses, attacks by Bemisia tabaci are still a primary concern to tomato growers. This is not simply due to direct damage caused by the whitefly to plants, by sucking sap and producing honeydew, but above all for the efficient transmission of various plant pathogenic viruses, such as the Begomoviruses causing the Tomato yellow leaf curl disease. Among many IPM applications which are being implemented for reducing phytosanitary risks connected with B. tabaci infestations on vegetables, biological and physical approaches are to be mentioned for their special importance. Chemical control, though maintaining its basic role, is rapidly moving to formulations having a lower environmental and toxicological impact, in the frame of new European regulations on sustainable use of pesticides. Within this context, phytosanitary use of sulphur will likely grow up, not only against fungal diseases or eriophyid mites but also to control infestations by some susceptible insect pests. Possibilities to apply gaseous sulphur, deriving by sublimation at more than 95 °C of the solid one, is improving the spread of this technique, allowing a better distribution on crops for the consequent rapid cooling and solidification of sulphur into a very fine powder with 5-14 µm particles. Trials aiming at evaluating the efficacy of sulphur, sublimated by means of electric devices, in the control of B. tabaci and Tomato yellow leaf curl disease on protected tomato crops have been conducted in Sicily. Data obtained show how this technique, in addition to slightly reduce infestation by the whitefly when applied at low population densities, modifies the adult behaviour by means of an unclear mechanism, consequently giving satisfactory results in containing the spreading of viral infections. It has been also noted how this technique for sulphur application, compared to the traditional one, allows a reduced labour-cost, a smaller quantity of sulphur employed and a minor amount of pesticides residues on fruits. Though not decisive in breaking down whitefly infestations, but considering also its contribution in reducing some important aerial fungal diseases, this technique is worth being considered within a strategy of integrated management of B. tabaci and its related viral problems.
|Titolo:||Sublimated sulphur to control Bemisia tabaci and Tomato yellow leaf curl disease in Italy|
|Data di pubblicazione:||2011|
|Appare nelle tipologie:||4.2 Abstract in Atti di convegno|