Physiological and vegetative changes in grapevines (cv. Alvarinho) promoted by biological control agents (BCAs): preliminary results

Abstract

The induction of a natural disease resistance in grape using several biological and/or chemical elicitors, known as Biological Control Agents (BCAs), has received increasing attention over the last years, and is now considered the elected strategy for disease management. Vegetative and physiological changes (number of leaves; roots and stem length; total photosynthetic pigments; leaf gas exchanges) promoted by four BCAs (Best Cure; Mycotric; FitoAlgas; BioClean) and four conventional chemical products (Maestro M; Flint; Aliette; Horizon) were evaluated in potted grapevines (cv. Alvarinho) comparatively to a control group (Ctl). Each compound was applied, independently, to a minimum of 12 plants (to Ctl plants just distillated water was added), every fifteen days, during July and August of 2007. The results, in the first year, do not reveal significant physiological differences between the treatments and the Ctl. In vegetative terms, some differences were observed in the roots and leaves. However, the results were erratic, eventually due to the short time of the experience. The trial will proceed for a 2nd and a 3rd year.