Basil is susceptible to biotic or abiotic stress, negatively interfering with growth and production. Thus, the objective of this work was to evaluate the physiological effects of the application of plant regulators in basil plants that suffer from water deficit. The experiment was conducted in a randomized block design (RBD) in a 2 × 4 factorial scheme, including plants that were subjected to water stress and those that were not. In addition, plants also received five doses of Stimulate^® composed of indolylbutyric acid (IBA) + gibberellic acid (GA3) + kinetin (Kt) with four repetitions each. The experiment was evaluated through the biochemical analyses of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and lipid peroxidation performed 20, 35, and 50 days after transplanting (DAT). The mixture of plant regulators attenuateds the effects through the increasing activities of these enzymes. The plants that received the highest dosages (9 and 12 mL L⁻¹) offered the best protetion. Parameters of growth measures such as number of leaves and leaf area also showed significant responses regarding the application of the plant growth regulators. The use of a mixture of plant regulators, despite satisfactory results, does not make basil economically viable because it presents inaccurate results regarding its use.

Abiotic stresses, such as water limitation, are significant limiting factors in basil production. One alternative to mitigate the harmful effects of this stress on plants is using plant growth regulators. This study’s objective is to evaluate different doses of plant regulators in basil under water deficiency conditions. A randomized block experimental design in a factorial scheme with two factors was used: the first factor referred to the water regimes of 50% and 100% stomatal conductance, the second to different doses of the plant regulator mixture: 0 mL L⁻¹ (control), 3 mL L⁻¹, 6 mL L⁻¹, 9 mL L⁻¹, and 12 mL L⁻¹. Each treatment consisted of 12 pots per repetition. Biometric parameters, chlorophyll a fluorescence, and gas exchange were analyzed. The plant regulator positively influenced basil plants under water deficiency, with the most pronounced effects observed at the 12 mL L⁻¹ dose: a 17% increase in the number of leaves, a fourfold increase in CO₂ assimilation and carboxylation efficiency, and a sevenfold increase in water use efficiency. Therefore, the application of plant regulators on basil is recommended to mitigate the negative effects of water stress, with the most significant results observed at a dose of 12 mL L⁻¹.

O objetivo do estudo foi avaliar os efeitos de diferentes substratos na produção de mudas de cultivares de manjericão (Ocimum basicilicum L.). O delineamento experimental foi o inteiramente casualizado, com cinco tipos de substratos (Carolina®, Provaso®, Provaso® + Fibra de coco, Fibra de coco + Turfa e Fibra de coco), sendo estudado em duas cultivares, Basilicão (BS) e Grecco a Palla (GP), com quatro repetições. As avaliações foram realizadas a partir do quinto dia após a emergência. Foi calculado o índice de velocidade de emergência (IVE) e percentual de emergência (E%). A avaliação final foi aos 30 dias após a semeadura (DAS), sendo analisadas as seguintes variáveis: diâmetro do colo (cm), altura da planta (cm), comprimento de raiz (cm), massa seca da parte aérea (g), massa seca de raízes (g), número de folhas, área foliar (cm²) e índice de qualidade de Dickson (IQD). Observou-se que para as duas cultivares BS e GP o substrato Carolina® foi o que proporcionou maior porcentagem de emergência, assim como o menor tempo médio de emergência. Para altura, diâmetro do coleto, número de folhas e área foliar, observou-se, nas duas cultivares, que os substratos, Fibra de coco® e Fibra de coco + Turfa foram menores. Para comprimento de raiz, Fibra de coco foi superior para BS e Fibra de coco + turfa para GP. Levando em consideração todas as características morfológicas analisadas, na cv. BS o Provaso® e Fibra de coco foram os melhores; para a cv. GP foi o Fibra de coco + turfa.