Sanitation from Venturia inaequalis using an antagonist Athelia bombacina to reduce ascospore inoculum

摘要

An efficient integrated control of Venturia inaequalis (Cke.)Wint. on apple requires a low Potential Ascospore Dose (PAD) of inoculum. Fertilisers and DMI fungicides are the substances currently available to eradicate the inoculum, but, in view of their limitations, natural antagonists can offer a new approach to the problem. Research has been carried out in Italy to assess the feasibility of using Athelia bombacina, the first and promising antagonist of V. inaequalis, to eradicate ascospore inoculum. Research on its activity has examined the performance of the antagonist in the field and in the laboratory, using several inoculation methods. Trials have also involved the addition of substances such as oils, wetting agents, urea and bran. Positive results were obtained, especially in field trials, where A. bombacina caused a consistent reduction in the pathogen ascospore inoculum, with an efficacy of 41% to 96% (see Abbott). On the whole, its eradicating efficacy was greater than urea and calcium-cyanamide treatments, but not as good as DMI fungicides that, however, in this type of application seem to involve a high risk of resistance development: In an attempt to improve the performance of the antagonist, the most promising results were obtained with adjuvants such as oils and wetting agents applied at different times following leaf-fall.