The effect of growing location on the iron concentration of potato and sweetpotato as determined by ICP-MS was evaluated using freeze dried and milled samples from peeled raw potato tubers and sweetpotato roots. Significant variation of the iron concentrations due to genotype (clone or variety), location and genotype × location interaction was found for potato and sweetpotato. However, for potato, the iron concentration levels were mostly attributed to genotype which account for 62.89% of the total variance whereas for sweetpotato the iron concentration levels were mostly attributed to location which account for 76.16% of the total variance.
Acidic soils seem to favor the iron absorption by the potato and sweetpotato plant while alkaline soils seem to diminish iron absorption. The mean iron concentration of the potato clones and varieties was higher in Yanamachay and Paltamachay, localities with acidic soils and high organic matter content; and was lower in Tacsana, the locality with the highest pH in the soil, lowest percentage of organic matter and highest proportion of sand. The mean iron concentration of the sweetpotato clones was drastically lower in Huaral, the locality with alkaline soil, than in San Ramon and Pucallpa. A broader and deeper designed study is planned to confirm the results found in this preliminary study.