Desenvolvimento e produção de gergelim inoculado com bacilos e sob restrição hídrica

Abstract

Sesame (Sesamum indicum L.) is a species native to tropical climates and its cultivation is indicated for the semi-arid region of Northeastern Brazil or as a second crop crop in the Cerrado biome of Brazil, as it is easy to cultivate; however, water restriction is one of the main limiting factors for agriculture in semi-arid regions. In the genus Bacillus, the species B. subtilis has been extensively studied due to its potential to provide direct and indirect gains in plant growth, as well as its ability to mitigate the deleterious effects of abiotic stresses on plants. In this context, the objective of this work was to evaluate the development and production of sesame inoculated with bacilli under water restriction. The experiment was conducted under field conditions, in the experimental area of Embrapa Algodão, located in Campina Grande, PB (07°13’S; 53°31’W) from February to July 2022. The experiment was in randomized blocks, in a factorial arrangement of 5 x 2: five managements, three inoculants based on bacilli, one management with chemical nitrogen, one treatment without nitrogen and two water regimes, with 3 replications. Growth variables (plant height and first fruit height, shoot and root dry mass) and production variables (number of capsules per plant; capsule diameter; capsule length; number of capsules opened per plant, weight total seeds and weight of 1000 seeds). In addition, nitrogen and phosphorus content in sesame leaves, free proline content and photosynthetic pigments were evaluated. The experiment data were submitted to analysis of variance (P≤0.05), the averages of treatments were compared by Tukey's test (P≤0.05) and water conditions were compared by Student's t test (P≤0.05). 05 The inoculants pant001 and ESA 402 established a significant interaction for the total production of seeds under water restriction, with an increase of 105.62% and 74% respectively, when compared to the treatment without nitrogen. For the weight of a thousand seeds, the treatments pant001 and ESA 402, under water restriction, provided an increase of 20.83% and 14.74%, respectively, compared to the treatment without nitrogen. Under water restriction, all treatments increased the total free proline content. The treatments inoculated with pant001, ESA 402 and nitrogen management favored the increase of photosynthetic pigments under water restriction.