Radicchio (Cichorium intybus l.) variety selection for the Chilean central area

- Significant G × E interaction between radicchio varieties in 2 mega environments.
- 'Leonardo' was the best variety for Polpaico-Lampa-Santo Domingo mega environment.
- 'Ciro' was a good alternative for Polpaico-Lampa-Santo Domingo mega environment.
- 'Tullio' was the best variety for Padre Hurtado mega environment.
- Diseases were main cause of radicchio exportable yield loss in central Chile.

In the Chilean market there are hybrid varieties of radicchio (Cichorium intybus L.) with high yield and homogeneity, where its main limitation is the high cost of the seed. The most important variety is 'Leonardo', which represents 90% of the market. Moreover, it is believed that there are open-pollinated varieties that could be used as an alternative to hybrids at lower cost. The study aim was to select open-pollinated varieties with equal or better exportable yield than 'Leonardo', in order to establish bases on the recommendation of cultivars for the Chilean central area. Eleven varieties of radicchio were evaluated in a randomized complete block design with five replications. The trial was conducted in four locations of Chilean central area, during seasons 2007-2008. At each site, three planting dates were evaluated. The combination of locality × transplant date generated 12 environments. Exportable yield, head weight, percentage of sick plants, early flowering bolting and exportable color were evaluated. Combined analyzes of variance, stability, additive main effects and multiplicative interaction model (AMMI), sites regression analysis (SREG) and principal components were made. The exportable yield of the varieties ranged from 23.34 t ha−1 ('Leonardo') to 6.84 t ha−1 ('CH121'), and the environments ranged between 25.89 and 8.18 t ha−1. The analysis of the exportable yield variance showed significant G × E effect. The type of radicchio (Treviso or Chioggia) was the main cause of interaction for exportable yield. In terms of exportable yield, 'Ciro' (Chioggia) could be considered as a good alternative to 'Leonardo' in the mega environment formed by the three planting dates of Polpaico, Santo Domingo and Lampa, while 'Tullio' (Treviso) could be an alternative in the three planting dates of Padre Hurtado. 'Ciro' yield 18.7% less than 'Leonardo' (P < 0.05) but showed better stability than 'Leonardo'; and 'Tullio' yield 24% more than 'Leonardo' in the three planting dates of Padre Hurtado (P < 0.05). Exportable yield reduction is mainly due to diseases.