Identification of acid-tolerant coffee genotypes in a coffee germplasm collection of Colombia

Jose Ricardo Acuña-Zornosa,Siavosh Sadeghian-Khalajabadi

doi:10.25186/.v15i.1727

Abstract

One of the limitations of coffee production in many regions of Colombia is the soil acidity. According to historical soil chemical analysis records, more than 50% of coffee farms have pH values below 5.0. Because acid-tolerant coffee varieties are not available, farmers use calcareous additives to correct the problem, which incurs associated labor and input costs. The objective of this work was to identify acid-tolerant genotypes of Coffea arabica. For two contrasting soils in the coffee-growing area of Colombia (Andisol and Entisol), the effect of soil acidity on the growth of 20 genotypes of Coffea arabica during the seedling stage was evaluated. The genotypes were wild accessions that make up the Colombian Coffee Germplasm Collection and the Castillo® Naranjal Variety, used as commercial material. Six months after the seedlings were transplanted into soils treated with or without acidity correction additives, the weight of the dry matter of the roots, stems and leaves was recorded. Later, the acid-tolerant genotypes were identified by means of the quadrant method and the tolerance index. The Timor Hybrid and Rume Sudan genotypes were identified as tolerant of the acidity of the two soil types. These genotypes could be used as progenitors in a coffee breeding program leading to a commercial coffee variety tolerant to soil acidity. Key words: Andisol; entisol; Coffea arabica L.; timor hybrid; rume sudan.

Highlights

Soil acidity limits global crop production to approximately 30% of the Earth’s surface, which corresponds to 50% of the world’s potentially cultivable land
Fifty-two percent of coffee-growing areas corresponded to volcanic ash-derived, P-fixing, high organic matter content soils with iron and aluminum oxides, hydroxides and pH values lower than 5.5, all of which are factors that negatively affect nutrient availability for coffee plants (Valencia, 1999)
The Timor Hybrid, S-17 Irgalem and Rume Sudan genotypes were distributed in quadrant IV, indicating tolerance to acidity in Entisol (Figure 2)

Summary

Introduction

Soil acidity limits global crop production to approximately 30% of the Earth’s surface, which corresponds to 50% of the world’s potentially cultivable land. According to soil analysis records from the Colombian coffee grower zone performed over the last 20 years, a high percentage of the tested samples had pH values lower than 5.0 and Al3+ levels greater than 1.0 cmolc kg-1 (Sadeghian, 2013). Fifty-two percent of coffee-growing areas corresponded to volcanic ash-derived, P-fixing, high organic matter content soils with iron and aluminum oxides, hydroxides and pH values lower than 5.5, all of which are factors that negatively affect nutrient availability for coffee plants (Valencia, 1999). For the growth of coffee in Colombia, in relation to the seedling stage, soils with pH values between 4.9 and 5.7 and Al3+ contents of less than 1.10 cmolc kg-1 are considered adequate (Sadeghian; Díaz, 2020)

Objectives

Methods

Results