Mycorrhizal contribution to water economy in agriculture under hot and dry climate: The case study of water melon in Algeria

Climatic warming and drought affect watermelon yields in Algeria, an important and water-demanding crop. This study aimed to test arbuscular mycorhizal (AM) fungi as an alternative to manage water deficit on watermelon culture. We experiment a watering regime gradient of 100%, 50%, 25 % and 5% of soil field capacity (FC) on mycorhized and non-mycorhized seedlings in greenhouse. The results showed that limited water irrigation reduced mycorrhizal colonization by 50.01% at the severe water stress (5%FC). However, the mycorrhizal dependency of watermelon plants to AM fungi increased with increasing water deficit and improved significantly growth parameter, among them flowering and root/shoot ratio, wich are indicators of a good yields. Thanks to AM fungi, shoot biomass of inoculated plants watering with only (5%FC) was similar to those obtain with non-mycorrhized plants more irrigated at 50%FC and higher than irrigated at 25%FC. Roots biomass of mycorrhized plant under water stress of 50%FC and 25%FC was similar to those obtained with the irrigation of 100% FC for the controls. Mycorrhizal inoculation can be used as a sustainable solution to manage the water resources, improve drought tolerance and growth of watermelon culture in areas with limited water availability.