The use of plant growth-promoting bacteria can be one option for mitigating the impact of abiotic constraints on different cropping systems in the tropical semi-arid region. The aim of this study was to evaluate growth, leaf gas exchange and yield in maize inoculated with Bacillus aryabhattai, and subjected to water and salt stress. The experiment followed a randomised block design, in a split plot arrangement, with six repetitions. The plots comprised two levels of electrical conductivity for the irrigation water (ECw): 0.3 dS m-1 and 3.0 dS m-1; the subplots consisted of three irrigation depths (ID1: 50%, ID2: 75%, and ID3: 100% of the crop evapotranspiration (ETc)); while the sub-subplots included the presence or absence of Bacillus aryabhattai inoculant. A water deficit of 50% of the ETc resulted in the principal negative effects on growth, reducing the leaf area and stem diameter. The use of Bacillus aryabhattai mitigated salt stress and promoted better leaf gas exchange by increasing the CO2 assimilation rate, stomatal conductance, and internal CO2 concentration. However, irrigation with brackish water (3.0 dS m-1) reduced the instantaneous water use efficiency of the maize. Inoculation partially reduced the effects of abiotic stress due to morpho-physiological traits, and increased yield potential under water deficit with no salt stress.

Nitrogen fertilization can provide greater nutritional support and mitigate salt stress in the millet crop. The aim of this study was to evaluate the physiological responses and agronomic performance of millet crops subjected to nitrogen fertilization and irrigation water salinity. The study was carried out in a greenhouse, using a completely randomized design in a 5 x 2 factorial scheme, with 4 rep-lications, with five doses of nitrogen (40; 60; 80; 100 and 120 kg ha-1 of N) and two levels of elec-trical conductivity of the irrigation water: 0.3 and 4.0 dS m-1. We concluded that salt stress in-creased leaf sodium levels and had a negative impact on stalk dry mass and panicle dry, leaf gas exchange, mineral element concentrations (K, P and Ca), and water use efficiency. The use of lower salinity water associated with increased nitrogen fertilization provides greater stalk dry mass and panicle dry, photosynthesis, water use efficiency, chlorophyll index, leaf potassium concentration, and biomass production. Salt stress negatively affected transpiration, stomatal conductance, leaf P and Ca levels, and increased leaf sodium levels as nitrogen fertilization increased in millet plants grown under pot conditions. These results can be used to create a strategy to reduce the negative impact of salt stress associated with the nutrition of millet plants, using nitrogen fertilization.