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

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.