Establishment of carrot populations (Daucus carota L.) in areas naturally infested by root-knot nematodes

Abstract

The reduced quality and low production of carrot is usually caused by nematodes. In Brazil, the most significant damage results from the root-knot nematodes attack. These nematodes are normally Meloidogyne incognita and Meloidogyne javanica, which are species with a wider distribution in the country. Thus, the objective of this study was to preliminarily evaluate the Embrapa Vegetables’ carrot breeding program for resistance to the root-knot nematode (M. incognita race 1 and M. javanica) in naturally infested fields. The carrot population ‘1112603’ was evaluated using 59 progenies and the cultivars ‘Brasilia’, ‘BRS Planalto’ and ‘Kuronan’ were used as control. Initially, to identify and quantify the number of juveniles 150 cm‑3 of soil, sampling was performed in the experimentation area. After the harvest, screening for resistance to root-knot nematodes was made based on the commercial roots weight (WCR), final population (FP) and reproduction factor (final population in the soil collected during the harvest/ initial population in the soil before sowing). There were significant differences only for the commercial roots weight. Twenty-five progenies were statistically similar to cultivar ‘Brasilia’ (40.09 t ha(‑1), while 34 progenies were similar to cultivars ‘Kuronan’ and ‘BRS Planalto’, which were 33.11 and 30.06 t ha(‑1) respectively. There were no significant differences for the nematological variable final population (FP) and reproduction factor.