The crop is considered as an annual or biennial plant and leaf harvesting is carried out periodically throughout its vegetative cycle. It also demands a lot of labor, as it needs staking, sprout removal and multiple harvests, which brings difficulties in the maintenance and evaluation of experiments. According to
Patcharin et al. (2013), the lack of information about the minimum number of harvests to adequately evaluate an experiment can lead the researcher to carry out more harvests than necessary to differentiate treatments (
Della Bruna et al., 2012). This can cause waste in the utilization of labor and financial resources (
Martuscello et al., 2007). The reliability of the good performance of a genotype throughout successive evaluations can be proven by the repeatability coefficient (
Neves et al., 2010), from which the ideal number of harvests can be estimated.