Comparative Study between Biocrystallization and Chemical Analyses of Carrots (<i>Daucus carota</i>L.) Grown Organically Using Different Levels of Green Manures

Abstract

ABSTRACT Carrots were grown organically using different levels of green manure, and examined by means of biocrystallization and chemical analyses. Firstly, to determine the ability of the biocrystallization method to discriminate the effects of green manure treatments (10), harvest times (4) and years (2), based on visual scoring of the morphological feature crystal coordination. Secondly, to examine the relationship between the biocrystallization variable and 11 chemical variables: Ca, Mg, fructose, glucose, sucrose, β-carotene, vitamin C, dry matter, total-N, nitrate-N and total amino acids. The field trial was designed in order to generate a wide range in N-availability. The chemical variables showed systematic differences in physiological and qualitative properties among the carrot samples. The biocrystallization variable discriminated the factors treatment and year (p < 0.01), with identical patterns of discrimination among the two years, and discriminated minor differences among the harvest times (p ~ 0.05). The lowest levels of coordination were found in samples from near-N-depleted plots, and vice versa; however the overall linear relationship to N-availability and the N-related variables was weak. In conditional covariance analyses, involving all 12 variables, the biocrystallization variable was in both years conditionally correlated only with total amino acids. When including treatment as discrete variable, the biocrystallization variable was conditionally correlated only with this variable. It was concluded that the biocrystallization variable detected differences among the treatments which could not be explained solely by differences in the chemical variables.