Various experiments were carried out to promote biological control under semi-arid ecological conditions. In vitro assay, Aspergillus flavus seemed to be the most effective bioagent against Fusarium oxysporum f. sp. niveum and Fusarium solani f. sp. cucurbitae with mycelial inhibition rate above 50%. Aspergillus flavus, Aspergillus niger, and Aspergillus terreus exhibited an exceptional hyperparasitism against F. oxysporum f. sp. melonis. The mycelial growth of five Macrophomina phaseolina isolates decreased in the presence of Trichoderma harzianum (44.42%). In greenhouse experiments, both A. flavus and A. fumigatus used preventively of melon inoculated with FOM generated the highest damage reduction rate of top and root dry weights (40-42 and 51-52%, respectively) and the lowest disease severity index (DSI). A. flavus was also effective in improving the plant development with the highest shoot (SDW) and root (RDW) dry weight values. Penicillium digitatum, Trichoderma harzianum, and Trichoderma viride treated preventively on watermelon and melon plants inoculated with M. phaseolina decreased the damage of SDW and RDW and DSI. The development rate revealed the growth improvement potential of T. harzianum (watermelon, 15%) and A. flavus (melon, 12%). Watermelon plants inoculated with F. solani f. sp. cucurbitae and treated curatively with Trichoderma erinaceum, T. viride, and A. flavus and other inoculated by F. oxysporum f. sp. niveum and treated by Trichoderma helicum recorded the highest values of growth parameters, similarly for T. erinaceum on melon plants inoculated by F. solani f. sp. cucurbitae. Among all treatments for plants inoculated by F. oxysporum f. sp. melonis, those three bioagents T. viride, T. erinaceum, and A. flavus revealed efficiency in plant growth. Trichoderma harzianum is the best bioagents against cucurbit soil-borne pathogens. Preventive treatment represents an effective strategy. Dipping roots with bioagent fungi suspension improve a good interaction pathogen antagonist.
Monosporascus cannonballus responsible for cucurbits Monosporascus root rot and vine decline, is worldwide spread notably in Tunisia. The most appropriate strategies to suppress disease development are those able to reduce the ascospores population using eco-friendly approach treatments. Seven soilborne fungal isolates were tested in vitro (by dual confrontation technique) and in vivo in the greenhouse as potential bioagents against three virulent M. cannonballus isolates. In vivo experiments were divided into two assays, preventive and curative treatments. Trichoderma viride and T. harzianum exhibited high inhibitory activities against M. cannonballus mycelial growth with values more than 90%, followed by Aspergillus niger (87.89%) and Paecilomyces victoriae (80.44%). Furthermore, these two Trichoderma spp. when applied preventively and curatively in in vivo trials, reduced significantly disease incidence (8.33% and 16.67-20.83%), root disease index (0.79-0.8 and 1.25-1.17), and reduced also ascospores index (1.5-1.54 asc/g of peat) and (2.54-2.42 asc/g of peat), respectively, in comparison with control treatments. Moreover, T. viride and T. harzianum enhanced the growth development of watermelon plants treated preventively and curatively in the greenhouse. They significantly improved different horticultural measurements with mean values of plant height (76.75-79.83 cm, and 81.83-80.92 cm), root volume (2.39-2.22 cm3, and 1.84-1.88 cm3), above grounds fresh weight (16.07-16.57 g, and 12.84-14.93 g) and dry wt. (2.49-2.6 g, and 2.66-2.70 g), underground fresh wt. (0.725-0.654 g, and 0.717-0.690 g) and dry wt. (0.147-0.214 g, and 0.156-0.152 g). Based on current results, it appears that Trichoderma spp. could be employed in soil treatments to promote watermelon plant growth and development.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.