AGRONOMIC PERFORMANCE AND WATER USE EFFICIENCY OF IRRIGATED CACTUS PEAR CULTIVARS

ABSTRACT Cactus pear is an alternative for animal feed in the semiarid region, and its productive characteristics can be improved with little irrigation. The objective of this work was to assess the agronomical performance and water use efficiency (WUE) of two cactus pear cultivars subjected to different irrigation water depths and define the best material genetic material for irrigated conditions in the semiarid region of the state of Minas Gerais (MG), Brazil. The experiment was conducted in Montalvânia, MG, during one year (2017-2018) using six treatments consisting of irrigation water depths based on the reference evapotranspiration (ET0) (without irrigation, 15%, 30%, 45%, 60%, and 75% ET0) and two genetic materials (Opuntia ficus-indica Mill. cv. Gigante, and Nopalea cochenillifera Salm-Dyck cv. Miúda). A randomized block design was used, in a with split-plot arrangement consisting of irrigation treatments in the plots and genetic materials in the subplots, with four replications. Growth evaluations were carried out from the third month after planting to the end of the growing cycle. Production variables and WUE were evaluated at the harvest. The irrigation water depths affected the growth variables, significantly (p<0.05). The water depths of 40% to 50% ET0 provided higher fresh and dry matter yields; the cultivar Miúda showed better performance than the Gigante. The WUE was affected by the irrigation water depths; the cultivar Miúda was the best option for the crop.

摘要：梨果仙人掌（cactus pear）是半干旱地区动物饲料的替代原料，辅以少量灌溉即可改善其生产性状。本研究旨在评估两种梨果仙人掌品种在不同灌溉水深下的农艺表现与水分利用效率（water use efficiency, WUE），并确定巴西米纳斯吉拉斯州（Minas Gerais, MG）半干旱灌区的最优栽培品种。本试验于2017-2018年在米纳斯吉拉斯州蒙塔尔瓦尼亚市（Montalvânia, MG）开展，共设置6个基于参考蒸散量（reference evapotranspiration, ET0）的灌溉水深处理（无灌溉、15%ET0、30%ET0、45%ET0、60%ET0、75%ET0），以及2份供试遗传材料：梨果仙人掌‘巨人’（Opuntia ficus-indica Mill. cv. Gigante）与胭脂仙人掌‘Miúda’（Nopalea cochenillifera Salm-Dyck cv. Miúda）。试验采用裂区型随机区组设计，主区因子为灌溉处理，副区因子为供试材料，设置4次重复。于定植后第三个月至生长周期结束期间开展生长指标测定，收获期测定产量相关性状与水分利用效率。结果表明：灌溉水深对生长指标具有显著影响（p<0.05）；当灌溉水深为40%~50%ET0时，鲜、干物质产量达到最高水平。供试品种中，‘Miúda’的表现优于‘Gigante’；水分利用效率同样受灌溉水深显著影响，‘Miúda’为本试验的最优栽培品种。