Drought tolerance of a microcitrangemonia when treated with paclobutrazol and exposed to different water conditions

The microcitrangemonia {[RPL ('Rangpur' lime) x YMCT ('Yuma' citrange) - 005] x MCP (Microcitrus papuana) - 011} (H011) demonstrates characteristics of agronomic interest that may benefit citriculture in different aspects, such as tolerance to water stress, irregularity of rainfall and lack of irrigation, which can cause drought stress conditions. In other varieties, one of the alternatives other than the use of tolerant varieties is the use of substances like paclobutrazol (PBZ). However, for citrus, there is a lack of information regarding the use of PBZ and the response to water deficit. The objective of this work was to evaluate the physiological behavior of H011 when compared to 'Rangpur' lime, both as rootstocks to 'Valencia' sweet orange and as nucellar seedlings, when exposed to different water conditions and to PBZ. The plants were cultivated in the presence and absence of PBZ and exposed to two water regimes (constant irrigation and water deficit), while water, physiological and morphological alterations were evaluated. The plants cultivated in the presence of PBZ in the soil showed greater tolerance to water deficit, and H011 as a nucellar seedling and as rootstock demonstrated greater efficiency in the use of water over time. The strategy adopted by H011 differed from the way of survival adopted by 'Rangpur' lime. Therefore, H011 presents the potential to be used in studies related to water stress tolerance in citrus.