Chlorophyll is an indicator of crop health and productivity. Measuring chlorophyll is usually done directly and requires significant time and resources. Indirect measurement of chlorophyll density using a handheld portable chlorophyll meter can reduce time. However, this information is very limited for Jerusalem artichoke. The objectives of this study were to examine the stability of chlorophyll density and SPAD chlorophyll meter reading (SCMR) and to evaluate the relationships between chlorophyll density and SCMR for different plant genotypes, at different plant ages and planting dates. Three Jerusalem artichoke varieties were evaluated for chlorophyll density and SCMR in a greenhouse at 13 planting dates from September to March in 2008/09 and repeated in 2009/10. The treatments were replicated four times. The chlorophyll density and SCMR evaluation were carried out at 30, 60 and 90 days after transplanting (DAT). Differences among planting dates were observed for chlorophyll density and SCMR. Evaluation at 30 DAT could best discriminate the differences in chlorophyll density and SCMR among Jerusalem artichoke genotypes. High and consistent association between chlorophyll density and SCMR was found across planting dates. SCMR can be used as a surrogate trait for chlorophyll density to screen a large number of accessions in Jerusalem artichoke breeding program for high levels of chlorophyll density
