Desempenho produtivo do sorgo cultivado sob déficit hídrico e inoculado com Priestia aryabattai

Abstract

Grain sorghum [Sorghum bicolor (L.) Moench] has great potential for cultivation in Brazil, as it is considered a hardy crop, usually grown in marginal areas, outside the ideal sowing season and under low water availability. Although it is tolerant to water deficit, insufficient water can negatively affect its productive performance. In this scenario, it is necessary to seek sustainable alternatives to mitigate the impacts of water deficit without increasing production costs. In this context, the use of bio-inputs based on Priestia aryabhattai may reduce the effects of water stress on agricultural crops. However, studies involving sorghum are still scarce. The objective of this study was to evaluate the productive performance of sorghum as a function of inoculation or co-inoculation with P. aryabhattai under different water regimes. The experiment was conducted in a greenhouse using a randomized block design, arranged in a 3 × 3 factorial scheme, with five replications. The factors evaluated were bio-input management (seed inoculation, seed inoculation combined with co-inoculation at flowering, and a non-inoculated control) and irrigation levels (85%, 50%, and 30% of available water capacity – AWC). The results showed that under moderate water deficit (50% AWC), inoculation and co-inoculation promoted an 11.6% increase in fresh mass compared to the control. Under severe water deficit (30% AWC), co-inoculation resulted in increases of 17.5% in fresh mass and 15.1% in dry mass relative to the control. Regarding root development, co-inoculation led to higher root dry mass both under non-deficit conditions and under severe water stress. Co-inoculation also increased the number of grains per plant by 37%, 28%, and 81% under the 85%, 50%, and 30% AWC regimes, respectively, in addition to increasing thousand-grain weight and grain yield, with gains of up to 66% under non-deficit conditions and up to 81% under severe deficit. It is concluded that co-inoculation with P. aryabhattai is effective in mitigating the effects of water scarcity, thereby increasing sorghum resilience and productivity.