Application of Trichoderma asperellum T34 on maize (Zea mays) seeds protects against drought stress

Abstract: Drought is currently one of the biggest threats to maize production. Trichoderma spp. is mainly used in agriculture as plant protection product with secondary beneficial effects on plants: improved growth, nutrient uptake and plant immunity. Here, we studied the physiological performance of maize plants under two different water regimes (fully irrigated and drought conditions) and three different seed treatments: application of Trichoderma asperellum strain T34, application of a chemical fungicide (CELEST XL) or the combination of both. Regardless of water regime, T34 treatment improved kernel P and C, kernel number and dry weight. Higher populations of T34 on the rhizosphere (T34 treatment) alleviated water stress better than lower T34 populations (T34+Q treatment). Under drought, T34 treatment improved leaf relative water content, water use efficiency, PSII maximum efficiency and photosynthesis. T34-treated maize seeds maintained sufficient T34 populations to alleviate drought throughout crop development suggesting an optimal dose of 104 and 105 colony forming units g−1 dry weight of rhizosphere under the studied conditions. This work helps to demonstrate the beneficial interaction between T. asperellum strain T34 and maize plants under drought