Performance of 'Emerald' and 'Jewel' blueberry cultivars under no-chill incidence

ABSTRACT Climate is a limiting factor for cultivating blueberries in new areas in Brazil, being the commercial production restricted only to the colder and high-altitude regions of the southern states. This study aimed to evaluate the performance of low-chill requirement 'Emerald' and 'Jewel' blueberry cultivars. For that, the stages of vegetative growth, sprouting, flowering fruiting and yield were assessed. The 'Emerald' cultivar has two peaks for both flowering and fruiting, with the main harvest period occurring between August and October, while the 'Jewel' cultivar shows two peaks for budding, but only one flowering peak and only one harvest, which extends from October through January. For both cultivars, the production occurs during the off-season of the internal and external markets, resulting in higher fruit prices. Growing both cultivars is feasible in a subtropical region with no-chill incidence, thus demonstrating that these cultivars have much lower chill requirements than those referred to in the literature, and favoring, this way, the fresh fruit production during the off-season of the main producing countries in the northern hemisphere.摘要：气候是巴西蓝莓拓展新种植区域的限制性因素，商业种植仅能局限于南部各州气候凉爽的高海拔区域。本研究旨在评估需冷量（chill requirement）较低的‘埃默拉尔德’（Emerald）与‘朱厄尔’（Jewel）两个蓝莓品种的种植表现。为此，研究对营养生长、萌芽、开花、结果及产量等阶段进行了测评。‘埃默拉尔德’品种的开花与结果均存在两个高峰期，主采收时段为8月至10月；而‘朱厄尔’品种的萌芽存在两个高峰期，但仅存在一个开花高峰与单次采收周期，采收期为10月至次年1月。两个品种的生产时段均处于国内外市场的鲜果销售淡季，因此可获得更高的果实售价。在无冷积发生的亚热带区域种植这两个品种均具备可行性，这表明这两个品种的需冷量远低于文献记载的常规品种，从而为在北半球主要蓝莓生产国的鲜果生产淡季开展种植提供了有利条件。