Base temperature, thermal time and phyllochron of Cichorium endivia L.

Resumo

The objective of this work was to determine the base temperature of escarole and to apply it in phenological analysis of crop during four growing periods. The work was carried out with escarole (Cichorium endivia L.) Escarola Lisa cultivar, at the Federal University of Santa Maria campus of Frederico Westphalen - RS. The experiment was conducted in randomized block design, with 10 replicates, each replicate being one plant. The sowing was carried out in four periods, being: P1 (02/15/2015), P2 (04/29/2015), P3 (07/22/2015), P4 (10/16/2015). The evaluations consisted of counting the number of leaves, performed three times a week after transplanting to the harvesting point. For determination of base temperature, the following methods were used: standard deviation in degree-days (SDgd), standard deviation in days (SDd), coefficient of variation in degree-days (CVgd), coefficient of variation in days (CVd), regression coefficient (RC), X-intercept. Thus, the base temperature for emission of two successive leaves in the Cichorium endivia L. is 4.7°C, obtained through the values of 4.0 and 5.5°C, observed in the SDgd and RC methods. For two leaves emission, it is necessary between 16.6 and 27.8°C day leaf^-1.