Pertot, I.

Several biocontrol agents (BCAs) have shown positive effects on plant growth. It is known that triazole fungicides have an effect on plant growth, chloroplast pigments and sterol biosynthesis of maize and a "greening effect" was observed on cereals after azoxystrobin treatments. The aim of this work was to compare the effect of a triazole (penconazole), a strobilurin (azoxystrobin) and two BCAs, Trichoderma harzianum T39 and Ampelomyces quisqualis sprays, on plant growth, chlorophyll content and mineral composition of healthy strawberry plants. Plants (cv. Elasanta) were weekly treated for three times under controlled conditions, starting from the third day after planting. The total chlorophyll content was not affected by any agent. T. harzianum T39 induced a temporary increase (not observed with the other treatments) of plant growth in the first two weeks post treatment, compared to untreated control, but at the end of the experiment the total leaf surface of T. harzianum T39 treated plants was similar to the other treated and untreated plants. Azoxystrobin and penconazole induced an increase in the development of aerial parts, which seems to be associated with a decrease in root growth. Azoxystrobin treatments increased phosphorus content in stem and leaves, while penconazole reduced potassium in leaves and other microelements in leaves and roots. T. harziamum T39, penconazole and azoxystrobin seem to affect the physiology of strawberry plants, conversely A. quisqualis, which is known to act as a powdery mildew hyperparasite, seems not to interfere with it.