Production of cuttings and nutrient export by Coffea canéfora in different periods in the Southwestern Amazon

ABSTRACT Cutting is the main vegetative propagation method used for the production of Coffea canephora plantlets. In this method, parent plants are conducted in a specific field, called clonal garden, which must be managed to produce clonal cuttings. The objective of this study was to evaluate the production of cuttings and the export of nutrients by Coffea canephora in different periods in the Southwestern Amazon. The experiment was carried out in a 6 × 3 split-plot scheme (repeated measures in time), consisting of the combination of six clonal Coffea canephora genotypes (plot) and three cutting collection periods (subplots). The genotypes were: C-057, C-088, C-089, C-125, C-130 and C-160; and the evaluation sampling times were January/2017, May/2017 and September/2017. The applied design was a completely randomized design with four repetitions. The dry season, from May to September, promotes lower orthotropic stem dry mass accumulation by Coffea canephora, but allows obtaining a larger number of viable cuttings for the production of clonal plantlets. Nutrient accumulation by orthotropic stems for cutting production follows the following order: N > K > Ca > Mg > S > P > Mn > Fe > Zn > Cu. Nutrient export by the cuttings follows a descending order: K > N > Ca > Mg > P > S > Mn > Fe > Zn > Cu.

摘要：扦插是刚果咖啡（Coffea canephora）种苗生产的主要无性繁殖方式。该方法中，母株种植于被称为无性系采穗圃（clonal garden）的专用地块，需通过精细化管理以获取合格的无性系插穗。本研究旨在评估亚马孙西南部地区刚果咖啡的插穗产量及不同时期的养分输出量。试验采用6×3裂区设计（时间重复测量），由6个刚果咖啡无性系基因型（主区）与3个插穗采集周期（副区）组合而成。供试基因型分别为C-057、C-088、C-089、C-125、C-130及C-160；采样评价时间为2017年1月、2017年5月与2017年9月。试验采用完全随机设计，设置4次重复。5月至9月的旱季会降低刚果咖啡直立茎的干物质积累量，但可获得更多用于无性系种苗生产的合格插穗。用于插穗生产的直立茎养分积累顺序为：氮（N）＞钾（K）＞钙（Ca）＞镁（Mg）＞硫（S）＞磷（P）＞锰（Mn）＞铁（Fe）＞锌（Zn）＞铜（Cu）。插穗的养分输出量则遵循如下降序排列：钾（K）＞氮（N）＞钙（Ca）＞镁（Mg）＞磷（P）＞硫（S）＞锰（Mn）＞铁（Fe）＞锌（Zn）＞铜（Cu）。