Mathematical approach to evaluation of the influence of different fertilization regimes on the main vegetative and generative development of carrot seed plants (Daucus carota L.)

Abstract

The present study aimed to use a mathematical approach (cluster, correlation and factor analysis) to assess the similarity and remoteness of the impact of different fertilization regimes and their grouping based on main morphological and generative indicators of carrot variety Tushon. Data obtained from field experiments conducted in the period 2017 – 2019 in an Experimental field at the Agricultural University – Plovdiv, Bulgaria were used. Increasing levels of nitrogen, phosphorus and potassium fertilization in two periods of application – once and twice, were studied. Height, diameter and weight of the carrot stalk, number and weight of leaves, and the number of umbels from I, II and III orders were investigated. It has been found that the twice application of mineral fertilizers causes better development of seed plants. The results of the cluster analysis are in line with the conclusions made in the analysis of the applied fertilization regimes and their impact on the vegetative and generative behaviors. As a result of the conducted correlation analysis, correlations between the studied indicators were established. The strongest positive correlation is between indicators of weight and the number of leaves. The main indicators that have the greatest influence on the division of fertilization variants into clusters are the weight and diameter of the stalk and leaf weight united in the first factor, explaining 45.196% of the total variance of the variables.