ABSTRACT
The present study aims to investigate the effectiveness of bioformulations based on endophytic fungi to control apple scab and Valsa canker disease in two orchards in the Aurès region (Algeria). In both orchards, the results showed that the treatment of senescent apple leaves by invert emulsions containing Trichoderma longibrachiatum and Chaetomium globosum harmed the ascogenesis of winter forms of Venturia inaequalis by reducing the number of ascospore-ejecting asci, the number of morphologically mature asci, and a considerable increase in the immature asci number. This antifungal activity was more essential in soil-incorporated leaves, showing the importance of the combination of treatments with cultural practices to efficiently control the apple scab disease. Furthermore, the disease incidence decreased by 52.63% and 50.68% in R'haouat and Bouhmama orchards, respectively. Moreover, the treatment of Valsa ceratosperma cankers with a biogel containing the endophytic yeast Metschnikowia sp. led to wound healing varying from 43.52% and 87.97% after 120 days but remained more considerable than conventional treatment with Folicur (tebuconazol). The current results open real opportunities concerning the implementation of eco-friendly and potent apple protection systems.
ABSTRACT
The potato is a staple food crop worldwide and the need for this product has increased due to the burgeoning population. However, potato production is highly constrained by biotic stress interference, such as Myzus persicae Sulzer, which causes serious yield losses and thus minimizing production income. The current study aims to investigate the effect of different formulations prepared as an invert emulsion with different concentrations of fungal culture filtrates derived from three endophytic fungi (genus Cladosporium) against Myzus persicae. All formulations have demonstrated an aphicidal activity, which increases with the increasing concentration of fungal filtrates. Furthermore, it has been noted that chitinolytic activity recorded for 12 days is important in Cladosporium sp. BEL21 isolated from dwarf mistletoe Arceuthobium oxycedri. The study of demographic and embryonic parameters of aphids settled on potato plants previously treated with formulations revealed a significant reduction in the numbers of colonizing aphids and a relative increase in the numbers of winged adults, especially in plants treated with BEL21-derived emulsion. The pre-treatment of plants may interfere with and negatively influence embryonic development and early maturity of the embryo and thus affect the fertility of parthenogenetic aphids. BEL21-derived emulsion can ensure effective and an inexpensive control of M. persicae for potato spring cropping systems. The current results open real opportunities concerning the implementation of ecofriendly and potent potato protection systems.
