Antagonistic potential of certain soilborne fungal bioagents against Monosporascus root rot and vine decline of watermelon and promotion of its growth

Rhouma, Abdelhak; Ben Salem, Ibtissem; M’Hamdi, Mahmoud; Boughalleb-M’Hamdi, Naima

doi:10.21608/NRMJ.2018.17864

Antagonistic potential of certain soilborne fungal bioagents against Monosporascus root rot and vine decline of watermelon and promotion of its growth

Document Type : Original Article

Authors

¹ Département des Sciences Biologiques et de la Protection des Plantes, Institut Supérieur Agronomique de Chott Mariem, 4042 Sousse, UR13AGR03, Université de Sousse, Tunisie

² Département des Sciences Horticoles et du Paysage, 4042 Sousse, Institut Supérieur Agronomique de Chott Mariem, 4042 Sousse, Université de Sousse, Tunisie

10.21608/NRMJ.2018.17864

Abstract

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.

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