Correlation coefficient analyses of horticultural characteristics of carrot genotypes (Daucus carota l.) in Southeastern Nigeria

A field experiment was conducted in 2018 and repeated in 2019 cropping season at the teaching and research farm of Crop Science, University of Nigeria, Nsukka to evaluate the horticultural characteristics of three genotypes of carrot. The experiment was a 3 x 5 split-plot laid out in a Randomized Complete Block Design and replicated four times. The treatments were three carrot genotypes (Safety Touchon France, Carotte Touchon AM and Carotte Touchon ETS) treated with organic and inorganic fertilizer combinations. The data collection and statistical analysis focused on key traits such as the number of harvested roots (NHR), root uniformity (RU), number of sorting groups (NSG), number of marketable roots (NMR), harvest index (HI), Root yield (RY) and whole plant biomass yield (WPBY). Results of the analysis of variance showed non-significant varietal effect for all characters in both years of study. Results of the correlation analysis indicated highly positive correlations between number of harvested roots and root uniformity (0.993) in 2018 and (0.729) in 2019, respectively. Root yield per plot exhibited similar positive correlations with NHR, RU, NMR, HI, FW, and WPBY during the two cropping seasons. Conversely, significant negative correlations were observed between number of sorting groups and number of harvested roots (-0.997) and number of marketable roots (-0.976). The harvest index showed highly negative relationships with NHR (-0.757) and percent marketable yield (-0.994). The principal component analysis (PCA) identified foliage weight, whole plant biomass yield and number of marketable roots as the major contributors of variation in both years.