Yield of organic potato cultivars in the subtropical region of Brazil

ABSTRACT The cultivar selection is fundamental to reach high potato yield in the organic production system. The objective of this work was to evaluate tuber yield and yield components and make suggestion for organic production system in South region of Brazil. The experiment was carried out in two crop seasons, 2013/2014 and 2014/2015, three trials, in Guarapuava, Paraná State and Caseiros, Rio Grande do Sul State, Brazil. Eight cultivars were evaluated (Agata, Clara, Eliza, Catucha, Aracy Ruiva, Itararé, Vitória and Cris) for total and marketable tuber yield, number of total and marketable tubers, and percentage of tuber dry matter content. A completely randomized block design in a split plot scheme, with trials as main plot and cultivars in sub plot, and four replications was used. The total and marketable yield varied according to the trial, however ‘Catucha’ stayed always in the group of high yielding cultivars, reaching around 28 and 23 t/ha of total and marketable yield, respectively. The relatively high yield of this cultivar was mainly due to high number of tubers, around eight and four/plant, total and marketable tubers, respectively. Moreover, this cultivar had the tubers with higher percentage of tuber dry matter content in all three trials (25; 16 and 21% in the trials 1; 2 and 3, respectively). Therefore, ‘Catucha’ is one of the suggested cultivars for the organic potato system in region of subtropical climate in Brazil.

摘要：在马铃薯有机生产体系中，品种选育是实现高产的核心基础。本研究旨在评估块茎产量及其构成因子，并为巴西南部地区的马铃薯有机生产体系推荐适宜品种。本试验于2013/2014和2014/2015两个生长季，在巴西巴拉那州瓜拉普阿瓦市以及南里奥格兰德州卡塞罗斯市共开展3组试验，共评估8个马铃薯品种（Agata、Clara、Eliza、Catucha、Aracy Ruiva、Itararé、Vitória及Cris）的块茎总产量、商品块茎产量、总块茎数、商品块茎数以及块茎干物质含量百分比。试验采用裂区设计的完全随机区组方案，以试验为主区、品种为副区，设置4次重复。结果显示，块茎总产量与商品产量因试验地点不同存在差异，但‘Catucha’始终位列高产品种行列，其块茎总产量与商品产量分别可达约28吨/公顷和23吨/公顷。该品种的高产特性主要源于其块茎数量优势：单株总块茎数约8个，商品块茎数约4个。此外，在全部3组试验中，‘Catucha’的块茎干物质含量均为最高，3组试验的干物质含量分别为25%、16%和21%。因此，‘Catucha’是巴西亚热带气候区马铃薯有机生产体系的推荐品种之一。