摘要：In accordance with the Directive 2009/128/EC, the spreading of biological methods based on the sustainable use of pesticides is one of the main objective aimed at limiting the risks caused by the use of pesticides on environment and health. Plant extracts offer significant advantages in terms of sustainable agriculture and represent a feasible alternative against infestant weeds and pests for disease control of crops. Garlic (Allium sativum L.) is known for its stimulating properties on plant growth and also protects plants due to its bactericidal and fungicidal activity.In this study, the antioxidant properties of aqueous extracts of garlic were evaluated by DPPH method, for the ability to provide stress resistance in plants. Moreovere, the bio-stimulant and repellent effect of 1 % (w/v) aqueous extract was evaluated on plants of zucchini (Cucurbita pepo L.) in an open field test, under the spontaneous attack of parasites and pathogens. The vegetative conditions of plants were assessed by measuring the chlorophyll content in vivo using the fluorimeter SPAD 5200. To evaluate the antioxidant properties of fruits, generallly stimulated by abiotic environmental stress, we determined the antioxidant activity on zucchini harvested, using the same DPPH method.The results showed a higher fruit yield in treated plants due to higher vegetative vigour, higher chlorophyll content in their leaves and better flower induction compared to control plants. The zucchini plants seemed to have taken advantage from the repellent effect against insect vectors and the preventive effect of garlic extract used. Moreover we found that zucchini fruits had lower antioxidant activity in treated plants than in control plants, due to their better physiologic conditions.The introduction of plant extracts to replace conventional chemicals, could provide significant benefits on the environment and human health.
