Conilon coffee outturn index: a precise alternative for estimating grain yield

ABSTRACT. Coffee outturn can be defined as the ratio between the harvested coffee and its respective processed grains. This character is greatly influenced by genotypic and environmental effects, and in breeding programs your analysis is costly and time-consuming. In this sense, the use of an outturn index to estimate coffee yield on experimental plots is a desirable measure aiming at reducing resources and time in postharvest evaluations. Thus, the present study aimed to evaluate the accuracy of the use of an outturn index equal to 4.0, in the estimation of Conilon coffee grains production. This index indicates that four kilograms of harvested fruit would be needed to obtain one kilogram of processed grains. Based on the average of 157 genotypes conducted in three trials and four harvests, we evaluated the relationship between harvested fruits and processed grains (FcBe), the observed (OGY), and the estimated grain yield per plant (EGY) based on FcBe equal to 4.0 (an outturn index). Descriptive statistics, adequation test for EGY, and the coincidence of occurrence of genotypes observations relating to the top 20% of all observations of OGY and EGY. In the estimation of grain yield in Conilon, the use of FcBe equal to 4.0 showed high precision in the average of the analyzed trials. However, further studies should be conducted to elucidate the effects of climate variables on the yield of Conilon coffee, especially in atypical crop years. Thus, the use of an outturn index becomes interesting in cases where the number of genotypes to be evaluated is very large and a screening of the promising ones is desirable.

摘要：咖啡出成率可定义为收获的咖啡鲜果与相应加工后咖啡豆的比值。该性状极易受基因型与环境效应的影响，且在育种项目中开展相关分析成本高昂、耗时耗力。有鉴于此，采用出成率指数估算试验田的咖啡产量，是降低采后评估资源与时间成本的理想方案。因此，本研究旨在评估当出成率指数为4.0时，其在科尼隆咖啡（Conilon coffee）籽粒产量估算中的准确性。该指数意味着，要获得1千克加工后的咖啡豆，需收获4千克咖啡鲜果。本研究基于157份基因型材料在3个试验、4次收获的平均数据，评估了鲜果与加工籽粒的比值（FcBe）、实际籽粒产量（OGY），以及基于出成率指数4.0估算的单株籽粒预估产量（EGY）之间的关联。具体分析内容包括描述性统计、EGY拟合优度检验，以及OGY与EGY全部观测值中前20%所涉及基因型的观测一致性。在科尼隆咖啡籽粒产量估算中，采用出成率指数4.0在所有分析试验的平均水平下表现出较高的精准度。不过，仍需开展进一步研究以阐明气候变量对科尼隆咖啡产量的影响，尤其是在非典型种植年份。因此，当待评估的基因型数量庞大且需要筛选优良基因型时，采用出成率指数将是极具应用价值的方案。