Sugarcane is one of the most important crops in the world, but subject to yield losses caused by sporadic droughts during the growing season. To mitigate the effects of drought stress, different strategies have already been used, including the foliar application of glycine betaine (GB). Thus, the present study aimed to evaluate the effect of GB spraying via leaf on gas exchange, chlorophyll fluorescence and on the sugarcane water status subjected to drought stress and rewatering. The experiment was carried out in a greenhouse, using the RB92579 sugarcane variety. A randomized block design was used, in a 3 × 2 factorial scheme, composed of three GB applications (G0—without GB, G1—one application and G2—two applications) and two water treatments: irrigated (Control) and non-irrigated (Drought Stress), with subsequent rewatering. The foliar application of GB minimized the impact of drought stress on gas exchange, on the photochemical efficiency of photosystem II (PSII) and leaf tissue water status in stressed plants. In addition, it favored the energy use in the PSII and reduced photoinhibition, a fact not observed in the G0 stressed plants. Thus, it can be inferred that the GB foliar application mitigates the negative effects of drought stress on gas exchange and photochemical apparatus of PSII in young sugarcane plants.

甘蔗是世界上最重要的农作物之一，但由于生长期的零星干旱而遭受产量损失。为了减轻干旱胁迫的影响，已经采用了不同的策略，包括叶面施用甘氨酸甜菜碱（GB）。因此，本研究旨在评估经叶片喷施国标对干旱胁迫和补水条件下气体交换，叶绿素荧光以及甘蔗水状况的影响。实验是使用RB92579甘蔗品种在温室中进行的。采用3×2析因方案的随机区组设计，由三个GB应用程序（G0-不使用GB，G1-一个应用程序和G2-两个应用程序）和两个水处理组成：灌溉（对照）和非灌溉（干旱胁迫），随后补水。GB的叶面施用将干旱胁迫对气体交换，对光系统II（PSII）的光化学效率和胁迫植物的叶片组织水分状况的影响最小化。此外，它有利于PSII中的能量消耗和减少的光抑制作用，而在G0胁迫的植物中未发现这一事实。因此，可以推断GB叶面施用减轻了干旱胁迫对年轻甘蔗植物中PSII的气体交换和光化学设备的负面影响。