Quality of ‘Tainung 1’ papaya produced by partial root zone drying

Resumo A significant portion of papaya production in the state of Minas Gerais originates from irrigated crops, and irrigation management using the partial root zone drying technique (PRD) is a fundamental alternative to reduce water waste. This study aimed to evaluate the quality of ‘Tainung 1’ papaya produced under PRD in semi-arid conditions of northern state of Minas Gerais. PRD treatments were composed of reduction of the calculated irrigation water (CIW) by 50%, applied on one side of the irrigation line, with alternation of 7, 14 and 21 days or without alternation and full irrigation, applying 100 % CIW in both lateral plant rows. Each experimental plot consisted of ten plants, and from six plants, fruits were harvested for evaluations at harvest point and when ripe. At harvest point, fruits had peel color, titratable acidity, ratio, pulp size and thickness similar to those produced without water deficit. Firmness, soluble solids content, fresh mass and central cavity diameter are distinct as a function of PRD condition. When ripe, only firmness varied according to PRD treatments. The quality of ‘Tainung 1’ papaya produced by partial root zone drying in semi-arid conditions was not compromised.摘要 巴西米纳斯吉拉斯州的番木瓜生产中，相当一部分来自灌溉种植，而采用部分根区干燥技术（partial root zone drying, PRD）开展灌溉管理，是降低水资源浪费的关键可行途径。本研究旨在评估在米纳斯吉拉斯州北部半干旱环境下，采用PRD技术种植的‘台农1号’（Tainung 1）番木瓜的果实品质。试验设置的PRD处理包括：将计算需灌水量（calculated irrigation water, CIW）削减50%，仅在灌溉管线单侧施水，并设置7天、14天、21天三种轮换周期；同时设置无轮换对照组与全灌溉对照组，双侧植株行均施100%CIW。每个试验小区包含10株植株，选取其中6株分别在果实采收期与完熟期采收果实，开展品质测定。在采收期，供试果实的果皮色泽、可滴定酸度、糖酸比、果肉大小与厚度，与无水分胁迫的常规种植果实基本一致；而果实硬度、可溶性固形物含量、鲜重及果心腔直径，则随PRD处理条件的不同呈现显著差异。在完熟期，仅果实硬度随PRD处理发生显著变化。本研究结果表明，在半干旱环境下采用部分根区干燥技术种植‘台农1号’番木瓜，其果实品质并未受到负面影响。