Yield evaluation of sweet potato genotypes using SPAD Chlorophyll Meter Reading

Abstract

SPAD chlorophyll meter reading (SCMR) can be used for indirect observation for chlorophyll content which is in locator to storage root yield produce efficiency. SCMR may be an alternative trait to evaluate the storage root yield of sweet potato. The objectives of this study were 1) to evaluate the effect of environment and genotype on vine length, SCMR and storage root dry weight and 2) to evaluate the relationship between SCMR, vine length and storage root dry weight of sweet potato. The field experiments were located at three locations including Rajamangala University of Technology Isan (L1-RMUTI), Chompra (L2-Chompra) and Sanom district (L3-Sanom). Ten sweet potato genotypes were evaluated in a randomized complete block design with three replicates. SCMR and vine length were collected at 30 and 60 days after planting (DAP). At the harvest date (90-100 DAP), storage root dry weight was recorded. The results showed that environmental factor effected on vine length and SCMR at 30 and 60 DAP and storage root dry weight. High variations among sweet potato genotypes were found in almost all parameters, except for SCMR 60 DAP. Interactions between environments and genotypes were found in all parameters. There was a significantly positive correlation between SCMR at 30 DAP and vine length at 60 DAP at L3 (r = 0.37*). Positive correlation between SCMR at 30 DAP and storage root dry weight were found in all locations (L1-RMUTI; r = 0.56**, L2-Chomphra; r = 0.44* and L3-Sanom; r = 0.47**, respectively). In addition, positive correlation between vine length at 30 DAP and storage root dry weight at L1 (r = 0.55**). A positive correlation between vine length at 60 DAP and storage root dry weight was found in L2 (r = 0.36**) and L3 (r = 0.37*).