Different nitrogen levels on vegetative growth and yield of conilon coffee (Coffea canephora)

ABSTRACT: The determination of nitrogen in plants by techniques that allow a fast diagnosis, based on plant growth characteristics, can be a useful tool for the nutritional management of coffee plants. Thus, this study evaluated growth and yield characteristics of irrigated conilon coffee in response to different nitrogen levels, resulting in the determination of the minimum N levels required to achieve the maximum yield, here called critical levels. The experiment was carried out in Colatina, Espirito Santo, Brazil, on plantations of conilon coffee, clonal variety Emcapa 8111, genotype 02. Six nitrogen levels were applied (0, 110, 220, 440, 880 and 1320 kg N ha-1) and the response in growth and yield characteristics periodically evaluated. There was a positive effect of the increasing N levels on yield, in that the N levels that provided 95% of the maximum yield (137.4 bags ha-1 and 108.5 bags ha-1) in the 2012/2013 and 2013/2014 growing seasons, respectively, were 420.7 and 543.1 kg N ha-1. There was also a positive effect of N levels on the growth characteristics and nitrogen contents, indicating their use as tools for a rapid nutritional diagnosis, with a view to optimizing the nitrogen management in Conilon coffee.

摘要：基于植物生长特性开展快速诊断以测定植物体内氮素含量，可作为咖啡植株营养管理的实用辅助工具。为此，本研究针对灌溉栽培的科尼隆咖啡（Conilon coffee），评估其在不同施氮水平下的生长与产量特性，进而确定实现最高产量所需的最低氮素水平（本研究将其定义为临界氮素水平）。本实验于巴西埃斯皮里图桑托州科拉蒂纳市的科尼隆咖啡种植园开展，供试品种为无性系Emcapa 8111、基因型02。设置6个施氮梯度（0、110、220、440、880及1320 kg N ha⁻¹），定期评估其生长与产量特性的响应情况。研究结果表明，施氮水平提升对产量具有显著正向促进作用：在2012/2013和2013/2014两个生长季，达到最高产量（分别为137.4袋/公顷与108.5袋/公顷）95%的施氮量分别为420.7 kg N ha⁻¹和543.1 kg N ha⁻¹。此外，施氮水平对咖啡生长特性及植株氮素含量同样存在正向影响，表明相关指标可作为快速营养诊断工具，用于优化科尼隆咖啡的氮素管理方案。