These results show that it may not be possible to recommend a generic optimal HA for different cultivars, as this will vary depending on region, the eldana infestation levels, and the eldana resistance rating of the cultivar. This implies that dedicated cultivar × HA screening for newly released cultivars in the target region(under prevailing eldana infestation levels) is needed. Alternate screening methods involving growth rate analyses may also be considered. The identified optimal harvest age of 15 and 22 months for the coastal and inland regions, respectively, may be used as target harvest ages with in the breeding programs for these regions.